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  • Inorganic Chemistry  (668)
  • Coleoptera
  • Column liquid chromatography
  • Industrial Chemistry
  • Seismology
  • ddc:330
  • 1985-1989  (872)
  • 1950-1954
  • 1986  (872)
Collection
Keywords
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  • 1985-1989  (872)
  • 1950-1954
Year
  • 1
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    Unknown
    Two new species of Onthophagus Latreille from the Philippine island of Samar (Coleoptera: Scarabaeidae) (1986)
    In:  Zoologische Mededelingen vol. 60 no. 19, pp. 277-283
    Details
    Publication Date: 2024-01-12
    Description: Onthophagus dejongi and bistiniocelloides, new species from Samar, are described and illustrated.
    Keywords: Coleoptera ; Scarabaeidae ; Onthophagus ; Philippines ; new species
    Repository Name: National Museum of Natural History, Netherlands
    Type: info:eu-repo/semantics/article
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  • 2
    Electronic Resource
    Electronic Resource
    Defensive alkaloid in blood of Mexican bean beetle (Epilachna varivestis) (1986)
    Springer
    Cellular and molecular life sciences 42 (1986), S. 204-207 
    Details
    ISSN: 1420-9071
    Keywords: Coleoptera ; chemical defense ; feeding deterrent ; alkaloid ; homotropane
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The blood of the Mexican bean beetle (Epilachna varivestis) contains a homotropane alkaloid, euphococcinine (1). The beetles ‘reflex bleed’ when disturbed, thereby deploying the alkaloid, which is provenly deterrent to spiders and ants. Newly emerged adults lack the alkaloid, but the compound builds up to deterrent levels in their blood within days. Eggs and larvae ofEpilachna are devoid of the compound.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01952471
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  • 3
    Electronic Resource
    Electronic Resource
    A model for the temperature and density dependent reemergence of the bark beetle Ips typographus (1986)
    Springer
    Entomologia experimentalis et applicata 40 (1986), S. 81-88 
    Details
    ISSN: 1570-7458
    Keywords: Ips typographus ; spruce bark beetle ; Coleoptera ; Scolytidae ; model ; reemergence ; density dependent ; temperature dependent ; degree-days ; poikilotherm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Ce modèle décrit la réémergence d'adultes d'I. typographus L. (Coleoptera, Scolytidae) en fonction de la densité et de la température. Les résultats obtenus en laboratoire à des températures constantes fournissent la distribution des réémergences et pour les dates de réémergence moyenne les différentes combinaisons de température de seuil et de degré de jour (°D). De toutes ces combinaisons, 167.71 °D au-dessus de 7,5 °C fournit la meilleure concordance entre les prévisions du modèle et les observations dans la nature à partir d'arbres fortement attaqués. Le modèle a montré un bon accord avec la réémergence observée dans deux groupes de branches attaquées dans différentes conditions de la température quand il a été ajusté aux faibles densités d'élevage. La discussion examine les possibilités d'application du modèle à l'étude de la biologie de la reproduction d'I. typographus et à l'aménagement forestier. La méthode utilisée pour construire le modèle pourrait être employée pour en développer d'autres chez des poikilothermes.
    Notes: Abstract A model is presented that describes the reemergence of parent spruce bark beetles, Ips typographus, based on breeding density and temperature conditions. Laboratory data obtained at one constant temperature provide the distribution of reemergence time and different combinations of threshold temperatures and degreedays (°D) at mean reemergence. Of these combinations, 167.71 °D above 7.5 °C gave the best correspondence between model prediction and field data obtained from densely infested standing trees. The model was in good agreement with the reemergence pattern found for two groups of infested logs under different temperature conditions when adjusted for the lower breeding density. The applicability of the model in the study of bark beetle reproductive biology and in forest management is discussed. The method used to construct the model should be useful in developing other models for poikilothermic processes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00187026
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  • 4
    Electronic Resource
    Electronic Resource
    Genetic variation in adaptation to foodplants among populations of the southern cowpea weevil,Callosobruchus maculatus: Evolution of oviposition preference (1986)
    Springer
    Entomologia experimentalis et applicata 42 (1986), S. 201-212 
    Details
    ISSN: 1570-7458
    Keywords: Callosobruchus maculatus ; Bruchidae ; Coleoptera ; behavior ; evolution ; genetic variation ; insect-plant interactions ; oviposition preference
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Vingt-deux lignées deC. maculatus Fab., liées à 6 plantes-hôtes, ont été examinées quant à leurs préférences — sans choix—parmi les graines de 9 légumineuses. Ces préférences se sont révél'ees semblables à celles observées lors de choix binaires; 3 paramètres ont donné les mêmes résultats: nombre moyen d'oeufs pondus par l'ensemble des femelles, nombre moyen d'oeufs émis par l'ensemble de celles acceptant la plante, fréquence des femelles acceptant la plante. L'analyse en composantes principales des préférences pour les 9 plantes a révélé que la majorité des mesures se situe sur les 2 premiers axes, qui ont rendu compte de 89% de la variation. Les performances des lignées sur le premier axe suggèrent qu'il s'agit d'un critère général de préférence. La classification automatique des plantes a montré un aspect général semblable à celui des composantes principales. Par ces 2 méthodes, les plantes ne se sont pas classées nettement selon leurs affinités taxonomiques. Bien que la classification automatique n'ait pas mis en évidence une similarité de comportement chez les insectes liés au même hôte, ceci était apparemment le cas. Les lignées liées à des hôtes présentant de fortes — ou à l'opoosé — de faibles préférences, ont montré différents seuils d'acceptation pour les 9 substrats de ponte. A l'opposé, il n'y a aucune preuve d'altération évolutive de la hiérarchie de préférences. On en a déduit que ces insectes étaient motivés par un petit nombre de stimulus, tels que les allélochimiques et al texture de tégument, pour déceler l'adéquation des substrats potentiels. (La microscopie électronique a suggéré une corrélation entre la texture du tégument et la hiérarchie des préférences de ces populations). La confiance dans les stimulus recueillis contribue à limiter les stratégies évolutives disponibles pour la population. A partir de là, la sélection en faveur —ou contre — des plantes, à l'origine, faiblement préférées, peut conduire, dans la niche de ponte, à l'incorporation — ou à l'exclusion — d'un groupe d'espèces taxonomiquemment éloignées, mais phénétiquement semblables. La probabilité d'altérations importantes de la hiérarchie des préférences paraît extrémement faible.
    Notes: Abstract A survey of 22 strains ofCallosobruchus maculatus associated with six different leguminous hosts indicates extensive genetic differentiation for oviposition preference. Female behavior suggests the existence of two distinct host preference groups among the nine oviposition substrates tested. Strains associated with plants in these two groups show distinct preference profiles. Genetic differentiation of oviposition preference is due to evolutionary modification of the threshold of acceptance of host plants, not to alteration of the preference hierarchy. From principal components analysis of these results, it is likely that very few independent plant traits govern oviposition preference.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00629305
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  • 5
    Electronic Resource
    Electronic Resource
    Age-specific flight behavior in relation to body weight and lipid content of Ips calligraphus reared in slash pine bolts with thick or thin inner bark (phloem) (1986)
    Springer
    Entomologia experimentalis et applicata 40 (1986), S. 197-207 
    Details
    ISSN: 1570-7458
    Keywords: body weight ; flight ; Ips calligraphus ; lipid ; longevity ; phloem ; pine ; Scolytidae ; Coleoptera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Le comportement de vol d'Ips calligraphus GERMAR (Scolytidae) a été examiné au laboratoire par une technique de vol captif. La génération parentale avait été artificiellement introduite, suivant la taille des adultes (1,6 à 2,1 mm) dans des morceaux de Pinus elliottii Engelm. variété elliottii au phloeme épais (TK=2,5 à 3,5 mm) ou fin (TN=0,5 à 1,5 mm) les larves se sont développées dans ces morceaux de pin. Le poids et la teneur en lipide des adultes obtenus à partir de TN étaient significativement inférieure à ceux de TK. Le poids des mâles les plus gros a été plus réduit que celui des femelles; les mâles les plus petits semblaient être moins efficaces dans l'initiation des attaques sur les arbres, et les femelles les plus petites ont eu une fécondité réduite. Les durées de vol quotidiennes pendant la vie des mâles TK vierges étaient en moyenne deux fois plus longues que celles des mâles TN. Les durées de vol quotidiennes étaient très variables: en moyenne moins de 20 minutes, mais la plus longue a été de 173 mn. En moyennes les adultes TN et TK ont commencé à voler, et volaient en plus grand nombre, le premier et le second jour après l'émergence. Ensuite la fréquence d'adultes volants et le pourcentage de surviveants, ont graduellement diminué jusqu'à tomber à zéro le neuvième jour. Les mâles TN et TK avaient des vols quotidiens plus longs et volaient environ 1 jour de plus que les femelles. L'activité de vol accrue des mâles reflète leur besoin de trouver dans la nature des arbres convenables; les vols des femelles peuvent généralement être plus brefs, étant plus directement orientés comme une réponse aux phéromones mâles. Les voiliers ont vécu environ 2 fois plus longtemps que les non-voiliers. Parmi les voiliers TK et TN il y avait une corrélation positive étroite entre le poids du corps et la durée totale des vols. Il n'y en a qu'une faible corrélation entre cette durée totale des vols et la longévité, suggérant un faible coût physiologique du vol. L'influence de cette durée des vols et du prélèvement consécutif de lipides sur la fécondité n'a pas été examinée. L'initiation au vol chez les individus fécondés a été sérieusement retardée (maximum le sixième jour) par rapport aux vierges, ce qui suggère un dégénérescence des muscles du vol associée à la reproduction, suivie d'une régénération importante, comme cela a été signalé chez d'autres Scolytes. Ces résultats contribuent à notre compréhension des facteurs conditionnant le comportement de vol et d'autres aspects fondamentaux de la biologie des insectes des pins. Une telle connaissance est nécessaire au développement d'une politique efficace de protection.
    Notes: Abstract Rearing larvae of Ips calligraphus (Germar) (Coleoptera: Scolytidae) in bolts of typical slash pine, Pinus elliottii Engelm. var. elliottii, with ‘thin’ (TN; 0.5–1.5 mm) phloem (inner bark) relative to adult beetle body width significantly reduced body weight and lipid content of emerging adults compared with ‘thick’ (TK; 2.5–3.5 mm) phloem-reared adults. Unmated (pre-nuptial) TK beetles averaged 2-fold longer daily and life-time flight duration than TN beetles. Daily flights were highly variable, averaging 〈20 min (longest daily flight=173 min). TK and TN beetles initiated flight, and the greatest number flew, on the first or second day after emergence form their rearing bolt; % of beetles flying and survival gradually declined to zero by day 9. Males (both TK and TN) averaged 2.5 days of flight, ca. 1 day longer than females. Fliers lived ca. 2-fold longer than non-fliers. Among TK and TN fliers, significant but weak positive correlations occurred between body weight and lifetime flight duration. Poor correlation between lifetime flight duration and longevity suggests little physiological cost to flight, but effects on fecundity were not assessed. Flight by mated, egg-laying (post-nuptial) beetles was substantially delayed (peaking on day 6), suggesting degeneration and subsequent regeneration of flight muscles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00349216
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  • 6
    Electronic Resource
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    Response of walking spruce bark beetles Ips typographus to pheromone produced in different attack phases (1986)
    Springer
    Entomologia experimentalis et applicata 41 (1986), S. 219-230 
    Details
    ISSN: 1570-7458
    Keywords: Coleoptera ; Scolytidae ; Ips typographus ; Y-tube olfactometer ; bioassay ; pheromone ; attack phase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Un olfactomètre à tube en Y, dont la description est donnée, a été utilisé pour examiner les réactions d'I. typographus L. par la marche à la présence de phéromones de congénères creusant des galeries dans des bûches d'Epicéa (Picea abies L.). Les insectes dans les bûches ont été répartis en 7 classes séquentielles, depuis l'élaboration de la chambre nuptiale par le mâle (phases 1–3), l'accouplement (4), et la ponte jusqu'à ce que les galeries de ponte aient 5 cm (5–7). Les mâles dans les phases précoces (1–2) étaient attractifs pour les 2 sexes dès 0,5 à 2,5 h après leur introduction, et ils le restaient pendant plus de 2 semaines. Les femelles qui se déplacent par la marche ont préféré nettement les bûches avec des mâles vierges à des bûches non habitées. De même elles ont préféré des bûches avec des mâles unis aux femelles à des bûches sans Ips. Ayant à choisir entre des bûches infestées par des mâles vierges ou expérimentés, les femelles ont préféré nettement les mâles vierges. Les mâle ont présenté une plus faible attraction aussi bien pour les bûches avec mâles vierges qu'avec mâles expérimentés, ils n'ont pas manifesté de préférence entre les 2. Les résultats sont interprétés comme des réponses adaptatives des 2 sexes aux variations dans la libération de phéromones par les insectes pendant les phases successives d'attaque et de colonisation de l'hôte.
    Notes: Abstract A Y-tube olfactometer is described which was used to assay the response of walking Ips typographus (L.) towards the pheromone from beetles excavating galleries in logs of Norway spruce [Picea abies (L.) Karst]. Beetles in the logs were categorized into seven sequential attack phases. Males in the early attack phases were attractive as early as 0.5 to 2.5 h after their introduction. These logs remained attractive for more than 2 weeks. Walking females strongly preferred logs with unmated males over uninfested logs and over logs containing males and females. They also preferred logs with males and females over uninfested logs. Responding males showed a weaker attraction than females to logs with unmated males. The results are interpreted as adaptive responses of the sexes to variation of pheromone release from beetles in the host during subsequent phases of attack and colonization.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00221251
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  • 7
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    Toxicity of the insect growth regulator diflubenzuron to the rove beetle Aleochara bilineata, a parasitoid and predator of the cabbage maggot Delia radicum (1986)
    Springer
    Entomologia experimentalis et applicata 42 (1986), S. 179-185 
    Details
    ISSN: 1570-7458
    Keywords: Aleochara bilineata ; Staphylinidae ; Coleoptera ; Delia radicum ; carbofuran ; diflubenzuron ; Dimilin ; Furadan ; insect growth regulator
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Lorsqu' appliqué dans des concentrations efficaces contre la mouche du chou Delia radicum L. (0.1, 0.01, 0.001% p/v dans de l'eau distillée), le Dimilin (diflubenzuron), un régulateur de croissance des insectes, n'a pas affecté l'éclosion des oeufs de Aleochara bilineata Gyllenhal, un staphylin prédateur et parasite. En application externe, à la plus forte concentration (0.1% p/v dans de l'eau distillée), cet inhibiteur de synthèse de la chitine s'est avéré non toxique pour les larves du premier stade, les stades larvaires qui se développent à l'intérieur du puparium de l'hôte, et les adultes. Le traitement au Dimilin n'a pas affecté la fertilité des staphylins adultes. Cependant, lorsque le diflubenzuron était dissous dans du diméthylsulfoxyde et appliqué sur l'exosquelette du puparium de l'hôte, l'émergence des adultes de A. bilineata était éliminée. L'insecticide conventionnel Furadan (carbofurane), à une concentration égale à la plus faible concentration de Dimilin utilisée (0.001% p/v dans de l'eau distillée), s'est avéré toxique à la fois pour les oeufs et pour les larves de A. bilineata.
    Notes: Abstract The insect growth regulator Dimilin®, common name: diflubenzuron, applied at concentrations effective against the cabbage maggot Delia radicum L., did not affect the hatching of eggs of the staphylinid predator and parasite, Aleochara bilineata Gyllenhal. Applied externally in distilled water, Dimilin was non-toxic to first instar larvae, to larval instars developing within host puparia, and to adults. When Dimilin was dissolved in dimethylsulfoxide, then applied to the exoskeleton of host puparia, emergence of A. bilineata adults was suppressed. The conventional insecticide Furadan, at a concentration (0.001% in distilled water) equal to the lowest concentration of Dimilin used, was toxic to both eggs and larvae of A. bilineata.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00343545
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  • 8
    Electronic Resource
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    Cantharidin biosynthesis in a blister beetle: Inhibition by 6-fluoromevalonate causes chemical disarmament (1986)
    Springer
    Cellular and molecular life sciences 42 (1986), S. 853-854 
    Details
    ISSN: 1420-9071
    Keywords: Coleoptera ; Lytta polita ; chemical defense ; cantharidin ; terpenoids ; fluorine ; metabolism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Biosynthesis of cantharidin in a blister beetle,Lytta polita, is effectively inhibited by 6-fluoromevalonate. Inhibition is attributed specifically to the fluorine substituent. Biochemical inhibition has not been demonstrated previously for an arthropod's defensive substance.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01941552
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  • 9
    Electronic Resource
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    The species composition and diversity of tree-dwelling beetles in deciduous oak and evergreen forests in central Japan; Relationship between the diversity index and sample size (1986)
    Springer
    Ecological research 1 (1986), S. 269-278 
    Details
    ISSN: 1440-1703
    Keywords: Coleoptera ; Community structure ; Species composition ; Species diversity ; Tree-dwelling beetles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract During the period fromlate May through December 1981, tree-dwelling beetles were regularly surveyed at three deciduous oak and two evergreen forests in the vicinity of Gifu City. Chrysomelidae and Curculionidae were abundant in these forests. The species diversity and the seasonal succession of species were most apparent in May and June. The three deciduous oak forests, with many species and high equitability, showed more diverse community structure, but fewer individuals, when compared with the two evergreen forests. Furthermore, the species compositions of the deciduous oak forests were seasonally and spatially more heterogeneous than those of the evergreen forests. A few dominant species, however, had a strong influence on the community structure. The relationship between the diversity index and sample size was examined. The diversity index changed with the sample size, and the range of the variation diminished as the sample size increased. However, equilibrium was not reached even in the largest sample size used in this study (20 samples). There was a significantly high correlation (P〈0.001) in diversity index between the smaller sample sizes (5, 10, 15) and the largest. It was, therefore, shown that community structures can be compared on the basis of the diversity indices from samples of constant size, even when the samples are small.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02348684
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  • 10
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    Economics of chemical defense in chrysomelinae (1986)
    Springer
    Journal of chemical ecology 12 (1986), S. 1189-1203 
    Details
    ISSN: 1573-1561
    Keywords: Defensive secretion ; egg defense ; allomones ; Salix ; salicin ; Coleoptera ; Chrysomelidae ; monoterpenes ; salicylaldehyde
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Chemical defense in chrysomelid larvae (subtribe Chrysomelina and Phyllodectina) is reviewed. Most species secrete autogenous monoterpenes. The diversity of their secretion is interpreted as a mechanism to reduce adaptation by predacious arthropods. The consequences of a host plant shift to the Salicacae are explored. Salicin from these host plants is used as a precursor for the salicylaldehyde secreted by the larvae of many species. This offers several advantages. It provides the larvae with an inexpensive and efficient defense. The recovery of the glucose moiety of the salicin contributes significantly to the larval energy budget. Adults sequester salicin in the eggs at concentrations which are toxic to ants. Owing to this maternal provisioning, neonate larvae produce salicylaldehyde from hatching onwards, whereas other species secreting monoterpenes are not protected at hatching. The secretion of salicylaldehyde by different species is considered to be chemical mimicry reinforcing visual aposematic signals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01639004
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  • 11
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    Reinvestigation of anhydroserricornin, (2S,3S)-2,6-diethyl-3,5-dimethyl-3,4-dihydro-2H-pyran, as a sex pheromone component for male cigarette beetle (1986)
    Springer
    Journal of chemical ecology 12 (1986), S. 179-186 
    Details
    ISSN: 1573-1561
    Keywords: Sex pheromone ; cigarette beetle ; Lasioderma serricorne (F.) ; Coleoptera ; Anobiidae ; serricornin ; 7-hydroxy-4,6-dimethyl-3-nonanone ; anhydroserricornin ; 2,6-diethyl-3,5-dimethyl-3,4-dihydro-2H-pyran
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Reinvestigation of the pheromonal activity of anhydroserricornin, (2S,3S)-2,6-diethyl-3,5-dimethyl-3,4-dihydro-2H-pyran, showed that the magnitude of its activity was less than 1/103 of that of serricornin, 7-hydroxy-4,6-dimethyl-3-nonanone, the sex pheromone of the cigarette beetleLasioderma serricorne (F.). Neither a synergistic nor an inhibitory effect of anhydroserricornin addition on the action of serricornin was observed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01045601
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  • 12
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    Identification of a volatile attractant forDiabrotica andAcalymma spp. from blossoms ofCucurbita maxima duchesne (1986)
    Springer
    Journal of chemical ecology 12 (1986), S. 687-699 
    Details
    ISSN: 1573-1561
    Keywords: Attractant ; Diabrotica virgifera virgifera ; Diabrotica undecimpunctata howardi ; Acalymma vittatum ; indole ; Cucurbita maxima ; electroantennogram ; floral volatile ; Chrysomelidae ; Cucurbitaceae ; Coleoptera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Fractionation of headspace volatiles fromCucurbita maxima blossoms by high-performance liquid chromatography resulted in the isolation of a single component which was highly active in an electroantennogram bioassay onDiabrotica undecimpunctata howardi antennae. This compound was identified as indole by gas chromatography-mass spectrometry. Field-trapping bioassays were conducted which indicated that indole is a potent attractant of the western corn rootworm,D. virgifera virgifera, and the striped cucumber beetle,Acalymma vittatum. The southern corn rootworm,D. u. howardi, did not respond, despite its strong EAG response. The sex ratio ofD. v. virgifera found in indole-baited traps varied seasonally. Males were trapped in abundance in late July and later September, 1983, while females were more abundant August and early September. The effectiveness of indole as aD. v. virgifera attractant also varied seasonally. A prolonged period of depressed trap catches occurred in early August 1983, during the silking and tasseling period of the corn in the field where trapping was carried out.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01012102
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  • 13
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    Electroantennogram responses by mountain pine beetles,Dendroctonus ponderosae Hopkins, exposed to selected semiochemicals (1986)
    Springer
    Journal of chemical ecology 12 (1986), S. 1603-1621 
    Details
    ISSN: 1573-1561
    Keywords: Mountain pine beetle ; Dendroctonus ponderosae ; Coleoptera ; Scolytidae ; electroantennograms ; pheromones ; kairomones ; inhibitors ; host selection ; aggregation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Electroantennograms (EAGs) were obtained forD. ponderosae to the bark beetle pheromonestrans-verbenol,cis-verbenol,exo-brevicomin,endo-brevicomin, frontalin, verbenone; to the kairomones, α-pinene, β-pinene, camphene, Δ-3-carene, limonene, myrcene; to a blend (1∶1∶1) oftrans-verbenol,exo-brevicomin, and myrcene; and to diacetone-alcohol. Male and female responses, in general, did not differ significantly over the whole EAG dose-response curves but differed at a few concentrations on many of the curves. There were more differences noted for pheromones than kairomones. The blend yielded among the largest EAGs in both sexes and appeared to show synergism. Responses of females were lower than those for males in most instances. Significant differences in responses by the two sexes were much fewer for the kairomones than the pheromones. EAG recovery rates tested at only one concentration showed significant differences between males and females for three pheromones,trans-verbenol,cis-verbenol, and verbenone, and two kairomones, camphene and Δ-3-carene. Thresholds were quite low for most of the odorants exceptcis-verbenol, camphene, verbenone, and diacetone-alcohol in females, andcis-verbenol, verbenone, α-pinene, and diacetone-alcohol in males. The results, using at least one EAG parameter, support behavioral and field studies involvingexo-brevicomin,trans-verbenol, frontalin, and the blend.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01020267
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  • 14
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    Determination of urinary 5-S-cysteinyldopamine by high-performance liquid chromatography with electrochemical detection (1986)
    Springer
    Chromatographia 21 (1986), S. 645-647 
    Details
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Electrochemical detection ; Cysteinyldopamine ; Tyrosinase ; Autoxidation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary 5-S-Cysteinyldopamine, a new metabolite of dopamine, was determined in urine by high-performance liquid chromatography with electrochemical detection. The catechol was detected in 14 of 21 melanoma patients and 7 of 21 normal subjects; the highest values were 657 μg/day for melanoma patients and 44 μg/day for normal subjects. These results suggest that the cysteine conjugate may arise from autoxidation of dopamine but tyrosinase may also participate in the oxidation.
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    URL: http://dx.doi.org/10.1007/BF02311920
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    Optimization of a reaction detector for analysis at the femtomol level of carbamate insecticides by HPLC (1986)
    Springer
    Chromatographia 21 (1986), S. 136-142 
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    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Chemical reaction detector ; Carbamate insecticides ; Quantitation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary For the determination of trace amounts of carbamate insecticides in vegetables the combination of liquid chromatography with post column chemical derivatization (chemical reaction detector) is used. In a two step reaction detector the carbamates are firstly saponified in 0.01 M sodium hydroxide at 80°C with a reaction time of 30sec. To this mixture OPA reagent is added to detect the methylamine generated in the saponification. Optimization strategies for this reaction are demonstrated. At a temperature of 80 °C a reaction time of 80 sec is sufficient for quantitative transformation of the methylamine. The peak dispersion can be reduced and hence the detection limit improved by decreasing the diameter of the tubes and by diminishing dilution through the addition of reagent. A 1∶24 ratio of reagent to column (reactor) effluent is possible with cyclone-type mixers. The quantitation of carbamates in different vegetables is demonstrated. The detection limit is 20ppb at a signal to noise ratio of 10∶1.
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    URL: http://dx.doi.org/10.1007/BF02311741
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    Optimization of enantiomeric separations with chiral bonded phases (1986)
    Springer
    Chromatographia 21 (1986), S. 205-213 
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    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Chiral phases ; Optimization of separation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The preparation and properties of chiral bonded phases with amino acid groups are described. These phases were used in non-polar eluents and in aqueous systems in the presence of Cu2+ ions in the ligand-exchange mode. The optimization of chiral resolution is demonstrated for both cases. With non-polar eluents similarity between bonded groups and solutes is required. The elution could be accelerated by non-protonic moderators. Ligand-exchange separation is influenced by the copper content of the eluent and the stationary phase, the organic moderator concentration, the pH and ionic strength of the buffer and by the temperature. Structural requirements of both the bonded groups and of the solutes for chiral separation are discussed.
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    URL: http://dx.doi.org/10.1007/BF02311888
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    Linear solvation energy relationships. A comparison of molar volume and intrinsic molecular volume as measures of the cavity term in reversed phase liquid chromatography (1986)
    Springer
    Chromatographia 21 (1986), S. 473-477 
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    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Reversed-phase capacity factors ; Cavity term ; Molar volumes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Reversed-phase liquid chromatographic capacity factors are well correlated by an equation of the form: $$logk' = (logk')_0 + mV/100 + s\pi ^* + b\beta + a\alpha $$ wheremV/100 measures the cavity term and π*, β, and α are the solvatochromic parameters that measure solute dipolarity/polarizability, hydrogen bond acceptor basicity, and hydrogen bond donor acidity respectively. Liquid molar volume (molecular weight divided by liquid density at 20°C) $$\bar V$$ , and computer-calculated intrinsic (van der Waals) molecular volume, $$\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{V} _I $$ , are compared as measures of the cavity term in a number of correlations. $$\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{V} _I $$ leads to more precise correlations as well as to a “cleaner” dissection of the multiple solute/solvent interactions. The opposing exoergic effect of solvent donor/solute acceptor hydrogen bonding, and endoergic cavity term are the main factors influencing HPLC capacity factors.
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    URL: http://dx.doi.org/10.1007/BF02341273
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    Determination of pyridate and its main metabolite CL-9673 in plant materials (1986)
    Springer
    Chromatographia 22 (1986), S. 40-42 
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    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Pyridate ; CL-9673 ; Reversed phase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The application of a simple reversed-phase, HPLC-UV method for the determination of the contact herbicide pyridate and its main metabolite 3-phenyl-4-hydroxy-6-chloropyridazine-known as CL-9673-in green cereals, grains and straw is described. The method is based on a simple extraction, separation of pyridate from its metabolite, hydrolysis of pyridate to CL-9673, high-performance liquid chromatographic separation of CL-9673 in both fractions using only one reversed phase column and UV-detection. The method is sensitive down to 3 ngg−1 CL-9673 in green plants and grain and 5ngg−1 in straw. In the range 0.05–1.0mgkg−1 recoveries are between 73.7% and 109% from green plants, between 77.7% and 102% from grains and between 77.3% and 87.5% from straw.
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    URL: http://dx.doi.org/10.1007/BF02257294
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    Liquid chromatographic capacity factor as an indicator of lipophilicity in a series of betablocker drugs (1986)
    Springer
    Chromatographia 22 (1986), S. 48-50 
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    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Betablocker drugs ; Lipophilicity ; Capacity factors ; Distribution coefficients
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The reverse-phase, high-pressure liquid chromatographic capacity factors (k') of a series of 18 betablocking agents were determined in order to establish correlations with their distribution coefficient values (D), obtained from four bibliographic sources. Under the three pH conditions studied (3.5, 6.2 and 7.5) statistically significant linear correlations (p〈 0.002) between log k' and log D values were obtained for the four series studied. In this series it is concluded that the k' factor is a useful and reliable relative lipophilicity parameter.
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    A limit to alternate column recycle chromatography (1986)
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    Chromatographia 22 (1986), S. 81-87 
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    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Recycle chromatography ; Pressure dependence ; Capacity factor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary It was found experimentally that the potential for routine, rapid high-efficiency separations by alternate column, recycle, reversed-phase chromatography is limited by the increase of capacity factors with pressure.
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    URL: http://dx.doi.org/10.1007/BF02257304
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  • 21
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    Specific retention behaviour of metal (III) tetraphenylporphyrins in non-aqueous, reversed high-performance liquid chromatography (1986)
    Springer
    Chromatographia 22 (1986), S. 43-47 
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    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Metalloporphyrins ; 5,10,15,20-Tetraphenylporphine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The Co(II), Ni(II), Fe(III) and V(IV) complexes of tetraphenylporphine (TPP) can be eluted at short retention times from a LiChrosorb RP-18 column with pure ethanol. However, both Mn(III) and Co(III) complexes of metal TPP chloride type are so strongly retained on the column that they cannot be eluted. While the retention of other metal teraphenylporphine complexes was not affected, that of the metal(III) complexes of the TPP chloride type especially MnTPPCl and CoTPPCl, decreases dramatically with an increase in the concentration of NH4Cl added into the mobile phase; a linear relationship between logk' and log[NH4Cl], with the slope of about−1, has been observed for these two metal(III) complexes in the NH4Cl concentration range from 2.5×10−4 to 1.3×10−2 mol/l. Thus, the specific control of the retention of the metal(III) complexes is enabled by conditioning the NH4Cl content of the mobile phase, and the chromatographic separation is demonstrated.
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    Factors affecting adsorption of organic solutes on cellulose acetate in an aqueous solution system (1986)
    Springer
    Chromatographia 22 (1986), S. 55-58 
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    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; 1-Octanol/water partition coefficient ; Cellulose acetate ; Reverse osmosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The adsorption properties of esters, aldehydes, ethers and amides on cellulose acetate, which is commonly used as a reverse osmosis membrane material, in an aqueous solution system were measured by high-performance liquid chromatography. The adsorption property was characterized with the specific retention volume. For a noncyclic homologous series the logarithm of the specific retention volume was linearly correlated with the logarithm of the partition coefficient between 1-octanol and water. The fact that the slopes of these regression lines are almost identical confirms that the dominant effect on adsorption is the hydrophobic interaction between cellulose acetate and the solute molecule. The intercept represents the effect of the polar groups on adsorption. The effect of the polar group decreases as follows: ―C(O)O―, ―CO―, HCON〈 〉 CH3CON〈 〉 ―OH, ―O―.
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    Equilibrium between α- and β-isomers of dihydroartemisinine and its multiple-peaks in high-performance liquid chromatography (1986)
    Springer
    Chromatographia 22 (1986), S. 77-80 
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    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Dihydroartemisine ; Interconversion equilibrium ; Multiple-peaks
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The interconversion between the α- and β-isomers and the multiple-peaks of dihydroartemisinine (dihydroqinghaosu) were investigated in reversed-phase, highperformance liquid chromatography. A convenient method using the Gaussian distribution function instead of the Schmidt graphical method for the theoretical calculation of the “diffuse” probability curves versus the fraction of the dead time on column as β form was introduced. Based on the theoretical probability curves and the experimental multiple-peak chomatograms, the effects of temperature and flow velocity on the accuracy and precision of analysis of dihydroartemisinine are indicated and the activation energy of the interconversion between α- and β-isomers of dihydroartemisinine is estimated.
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    Nucleotide pools and energy charges of smooth molluscan muscles analysed by reversed-phase, ion-pair, high-performance liquid chromatography (1986)
    Springer
    Chromatographia 22 (1986), S. 99-102 
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    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Nucleotides ; Mytilus edulis ; Smooth muscle
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A method is described for the analysis of the 5′ mono-, di- and triphosphates of adenosine, guanosine, uridine and cytidine, as well as uridinediphosphate-glucose and cyclic AMP. Separation is achieved by reversed-phase ion-pair chromatography with linear gradient elution. Application of this method to the analysis of nucleotides in smooth molluscan muscles is described, including the determination of cAMP-levels and the calculation of energy charges for all of the four nucleotide systems.
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    High-performance liquid chromatographic separation of hematoporphyrin and its nickel, copper and zinc complexes on octadecyl-bonded stationary phase (1986)
    Springer
    Chromatographia 22 (1986), S. 132-134 
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    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Porphyrin ; Metalloporphyrin ; Hematoporphyrin IX
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The feasibility of reversed-phase high-performance liquid chromatography for the separation of metal complexes of hematoporphyrin IX (Hp) is described. The retention order, Zn-complex〈Hp (free acid)〈 Ni-complex〈Cu-complex, is regular on an octadecylbonded stationary phase with different compositions of an aqueous methanol mobile phase. These four compounds can be successfully separated within about 8 min on a LiChrosorb RP-18 column (250×4-mm i.d.) with a 85:15 (vol/vol) mixture of methanol and phosphate buffer (pH 3) at a flow rate of 1 ml/min.
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    Analysis of flavonol aglycones in wine extracts by high performance liquid chromatography (1986)
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    Chromatographia 22 (1986), S. 157-159 
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    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Flavonol aglycones ; Isocratic elution ; Wine phenolics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary An HPLC isocratic elution procedure which allows the separation of flavonol aglycones in wine without interference from other phenolics of low molecular weight is described. The method has been applied to the separation, identification and quantitative estimation of flavonol aglycones in ether extracts of different Spanish wines (red and white table wines and Sherry finos). The results suggest that these determinations, associated with other analyses, would permit the chemical characterization of wines.
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    Trace analysis of selected benzidine and diaminodiphenylmethane derivates in urine by means of liquid chromatography using precolumn sample preconcentration, UV and electrochemical detection (1986)
    Springer
    Chromatographia 22 (1986), S. 138-146 
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    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Benzidine+diaminodiphenyl methane derivatives ; Preconcentration from urine ; UV and electrochemical detection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary For the title compounds 4,4′-DADPM, MOCA, 3,3′-DCB, 4-ADP and 4-ADPA listing on the EPA priority pollutant list, an analytical practicable, reliable, reproducible and sensitive procedure is required. Therefore a new method has been developed for the routine determination of these toxic aromatic amines in urine at the ppb level. The quantitative determination of amines is a suitable procedure of occupationally exposed persons. Urine sample preparation is done using simple liquid-liquid extraction followed by a precolumn enrichment (PRP1-material; Hamilton). Breakthrough measurements were done using an enrichment column packed with PRP1 material. The capacities of the studied amines ranged from 21.9mg/g to 96.6mg/g, while influent concentrations differed from 28.3mg/l to 332.0mg/l. The advantages of electrochemical detection regarding to selectivity and sensitivity are clearly indicated in this paper. Separation has been achieved applying reversed-phase-high-performance-liquid chromatography (LiChrosorb RP 18/5μm) followed by electrochemical or UV-detection. The detection limits employing an electrochemical detector at a potential of 1 V range from 2.2ng to 12.1ng. UV detection at 254 nm and 280 nm is about 10–100 times less sensitive. Recoveries from spiked water samples at the 5ppb levels were 75% to 96% respectively. The standard deviation of the developed procedure varies from 5.3% to 14%. Day-to-day repeatability is good.
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    Non-aqueous, reversed-phase, high-performance, thin-layer chromatography and column liquid chromatography of metal complexes of porphine (1986)
    Springer
    Chromatographia 22 (1986), S. 160-164 
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    ISSN: 1612-1112
    Keywords: Thin layer chromatography ; Column liquid chromatography ; 21H, 23H-Porphine ; Metalloporphyrin complexes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The chromatographic mobility of 21H, 23H-porphine and its Ni(II), Cu(II), Zn(II) and Pd(II) complexes were investigated by high-performance thin-layer chromatography on an octadecyl-bonded, silica gel plate with various polar organic solvents including alcohols, acetonitrile, dimethylsulfoxide and propylenecarbonate. The mobility generally decreases according to the central metal ion of the complex as follows: Zn(II)〉(free porphine)〉Ni(II)〉Pd(II)〉Cu(II). Methanol is a good choice of solvent for the separation of these metal porphine complexes. Successful separation of porphine and the four metal complexes is accomplished within 13 min on a LiChrosorb RP-18 column with methanol eluent.
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    Retention prediction of polycyclic aromatic hydrocarbons in reversed phase liquid chromatography with various mobile phase compositions and column temperatures (1986)
    Springer
    Chromatographia 22 (1986), S. 13-18 
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    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Mobile phase composition and column temperature ; Retention prediction ; Polycyclic aromatic hydrocarbons
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The relationship between the logarithmic capacity factor measured in reversed-phase liquid chromatography and the operating conditions including the mobile phase composition and the column temperature is investigated. The strategy described herein can offer the possibility to predict the retention of polycyclic aromatic hydrocarbons without any experiments and standard materials, by utilizing equations describing the relationships between retention, temperature, mobile phase composition and physicochemical properties of the solutes previously stored in the program of the microcomputer-assisted retention prediction system. This concept is one of the most promising techniques for the optimization of the separation conditions in reversed-phase liquid chromatography.
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    Crocheted PTFE reactors for post-column photochemistry in HPLC (1986)
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    Chromatographia 22 (1986), S. 231-234 
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    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Post-column reactor ; Crosheted PTFE construction ; Photochemical reaction detection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Construction of crocheted photochemical reactors for use in high performance liquid chromatography is described. The design of these reactors is optimal for low intensity light sources because of their cylindrical configuration. Band broadening is minimized by the use of tightly crocheted narrow bore tubing and fittings modified to reduce dead volume. These reactors are suitable for most post-column photochemical reactions with the additional possibility of serving as mixing/delay coils, deoxygenation devices for electrochemical detectors, and as low dispersion detector cells for chemiluminesckent reactions.
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    Inhibitory action of (4S,6S,7R)-isomer to pheromonal activity of serricornin, (4S,6S,7S)-7-Hydroxy-4,6-dimethyl-3-nonanone (1986)
    Springer
    Journal of chemical ecology 12 (1986), S. 83-89 
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    ISSN: 1573-1561
    Keywords: Sex pheromone ; cigarette beetle ; Lasioderma serricorne (F.) ; Coleoptera ; Anobiidae ; serricornin ; 7-hydroxy-4,6-dimethyl-3-nonanone ; inhibitory action of diastereoisomer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract By adding the effects of a series of the stereoisomers to the pheromonal activity of serricornin, (4S,6S,7S)-7-hydroxy-4,6-dimethyl-3-nonanone, the sex pheromone of the cigarette beetleLasioderma serricorne (F.) was investigated. The experiments using synthetic enantiomeric mixtures and optically active stereoisomers showed that the (4S,6S,7R)-isomer inhibited significantly the pheromonal activity of serricornin.
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    Components of moribund American elm trees as attractants to elm bark beetles,Hylurgopinus rufipes andScolytus multistriatus (1986)
    Springer
    Journal of chemical ecology 12 (1986), S. 583-608 
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    ISSN: 1573-1561
    Keywords: Hylurgopinus rufipes ; Scolytus multistriatus ; Coleoptera ; Scolytidae ; sesquiterpenes ; host attractants ; Dutch elm disease ; kairomone ; pheromone ; elm bark beetles ; Ulmus americana
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Hylurgopinus rufipes male and female beetles were attracted to American elms infected with Dutch elm disease, and to American elms killed by injection of cacodylic acid.H. rufipes was also attracted to solvent extracts of elm, or to Porapak Q-trapped volatiles from elm. The major components of attractive fractions of Porapak Q-trapped volatiles were isolated, identified, and tested in field bioassays. Several artificially compounded mixtures of sesquiterpenes were attractive toH. rufipes, although no bait tested was as attractive as diseased tree controls. Laboratory bioassays withH. rufipes were marginally successful. In laboratory bioassays, nine of 14 sequiterpenes identified from active fractions of Porapak extracts elicited significant response fromScolytus multistriatus male and female beetles: δ- and γ-cadinene, α-cubebene, γ-muurolene, and β-elemene were most active. However, in field tests, none of the sesquiterpenes alone or in combination significantly attractedS. multistriatus, nor did they significantly enhance the attraction ofS. multistriatus to female-produced pheromone components (4-methyl-3-heptanol [H] and α-multistriatin [M]). In other field tests, α-cubebene (C) significantly enhanced response ofS. multistriatus to H plus M, but foliage, logs, or chips of healthy elm did not enhance trap catch to HMC.
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    Isolation of feeding deterrents against argentine stem weevil from ryegrass infected with the endophyteAcremonium loliae (1986)
    Springer
    Journal of chemical ecology 12 (1986), S. 647-658 
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    ISSN: 1573-1561
    Keywords: Perennial ryegrass ; Lolium perenne ; Gramineae ; Argentine stem weevil ; Listronotus bonariensis ; Coleoptera ; Curculionidae ; Acremonium loliae ; Acremonium coenophialum ; endophyte ; bioassay ; induced resistance ; feeding deterrent ; peramine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Infection of ryegrass (Lolium perenne) by an endophytic fungus (Acremonium loliae) confers resistance against the Argentine stem weevil (Listronotus bonariensis). Extracts from ryegrass clones, infected and uninfected withA. loliae, were compared in a feeding choice bioassay, and several fractions were identified which affected stem weevil feeding behavior. One stem weevil feeding deterrent, peramine C12H17N5O, has been isolated from infected ryegrass and partially characterized as a basic indole derivative. Extracts from culturedA. loliae had no effect on stem weevil feeding behavior nor was peramine detected in the fungal cultures examined. Peramine and the other active substances are hydrophilic in contrast to the lipophilic properties reported for the neurotoxic lolitrems also isolated from ryegrass infected withA. loliae and associated with causing ryegrass staggers disorder in livestock. It is suggested that ryegrass staggers and stem weevil feeding deterrency may arise by different biochemical mechanisms.
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    Necrodols: Anti-insectan terpenes from defensive secretion of carrion beetle (Necrodes surinamensis) (1986)
    Springer
    Journal of chemical ecology 12 (1986), S. 1407-1415 
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    ISSN: 1573-1561
    Keywords: Coleoptera ; Silphidae ; Necrodes surinamensis ; carrion beetle ; monoterpenes ; iridoids ; necrodols ; defensive secretion ; insect repellent ; insect irritant ; bioassay
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Two compounds recently isolated from the defensive gland ofNecrodes surinamensis, α-and β-necrodol, first representatives of a new category of monoterpenes (the necrodanes), are shown to be repellent to ants and other insects and irritating to cockroaches and flies. The compounds doubtless play a defensive role inNecrodes. The possible long-range applied significance of research on insect repellents is discussed.
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    Defensive mechanisms of loblolly and shortleaf pine against attack by southern pine beetle,Dendroctonus frontalis Zimmermann, and its fungal associate,Ceratocystis minor (Hedgecock) Hunt (1986)
    Springer
    Journal of chemical ecology 12 (1986), S. 1397-1406 
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    ISSN: 1573-1561
    Keywords: Dendroctonus frontalis ; Coleoptera ; Scolytidae ; Ceratocystis minor ; Pinus ; bark beetle ; fungus ; defense ; monoterpenes ; soluble sugars ; resin flow ; hypersensitive lesion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Loblolly and shortleaf pine growing on a single site in the North Carolina piedmont were examined to determine similarities and differences in their defensive mechanisms against the southern pine beetle,Dendroctonus frontalis Zimmermann, and its fungal associate,Ceratocystis minor (Hedgecock) Hunt. Both species responded to wounding and fungal inoculation by forming a hypersensitive lesion around the wound site. There were significantly less soluble sugars and more monoterpenes in the lesion tissue than in unwounded inner bark. The two species were similar in resin flow rate and inner bark soluble sugar content, but the loblolly pines had thicker bark, longer hypersensitive lesions, and a higher concentration of inner bark monoterpenes. Inner bark monoterpene composition was also significantly different between the two pine species. It is hypothesized that two different defensive strategies against southern pine beetle attack may be utilized.
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    Identification of cantharidin in false blister beetles (Coleoptera, Oedemeridae) from florida (1986)
    Springer
    Journal of chemical ecology 12 (1986), S. 741-747 
    Details
    ISSN: 1573-1561
    Keywords: Cantharidin ; defense ; chemical ; vesicant ; antifeedant ; Heliocis repanda ; Oxycopis thoracica ; Coleoptera ; Oedemeridae ; sexual dimorphism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Cantharidin, a potent vesicant and antifeedant, is identified for the first time in two oedemerid beetles from the western hemisphere. Amounts of the substance per beetle were found to range from 2 to 7 μg inHeliocis repanda and from 15 to 35 μg inOxycopis thoracica. Females had two to three times more cantharidin than males of the same species. Cantharidin loads of these beetles are sufficient to irritate human skin.
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    Orientation of boll weevil,Anthonomus grandis boh. (Coleoptera: Curculionidae), to pheromone and volatile host compound in the laboratory (1986)
    Springer
    Journal of chemical ecology 12 (1986), S. 91-98 
    Details
    ISSN: 1573-1561
    Keywords: Boll weevil ; pheromone ; host odor ; olfactometer ; preference ; Anthonomus grandis ; Coleoptera ; Curculionidae ; cotton ; behavior ; bioassay ; orientation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Behavioral responses of male and female boll weevils to the aggregation pheromone, grandlure, and the major volatile of cotton, β-bisabolol, were investigated using a new dual-choice olfactometer. Dosage-response experiments revealed both males and females to be attracted by the aggregation pheromone at the 1.0 μg dosage. However, only males were attracted to β-bisabolol (1.0 μg). Both sexes were repelled by the highest dosage ofβ-bisabolol tested (10 μg). In preference experiment, males chose grandlure over β-bisabolol, while both sexes chose the combination of grandlure + β-bisabolol over β-bisabolol alone. There was some evidence for synergism between pheromone and plant odor for the females. The results correlate well with previous electrophysiological and behavioral experiments.
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    Sex-specific production of ipsdienol and myrcenol byDendroctonus ponderosae (Coleoptera: Scolytidae) exposed to myrcene vapors (1986)
    Springer
    Journal of chemical ecology 12 (1986), S. 1579-1586 
    Details
    ISSN: 1573-1561
    Keywords: Dendroctonus ponderosae ; bark beetle ; Coleoptera ; Scolytidae ; myrcene ; aggregation pheromones ; ipsdienol ; myrcenol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Male mountain pine beetles,Dendroctonus ponderosae Hopkins, produced ipsdienol [97.0% ± 0.3S-(+)] and myrcenol (90.3% ± 4.0E) when exposed to myrcene vapors. Females which were exposed to myrcene vapors did not produce any ipsdienol, but did produce low levels of myrcenol (98.0% ± 0.7E). Neither sex produced detectable levels of ipsdienol or myrcenol when fed for 24 hr on lodgepole pine,Pinus contorta var.latifolia Engelmann. The sex-specific conversion of myrcene to ipsdienol and myrcenol suggests that these compounds may have behavioral significance within the species. In addition, the S-(+)-ipsdienol produced by maleD. ponderosae probably functions as a repellent allomone againstIps pini (Say).
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    Cellulose digestion inMonochamus marmorator Kby. (Coleoptera: Cerambycidae): Role of acquired fungal enzymes (1986)
    Springer
    Journal of chemical ecology 12 (1986), S. 1057-1070 
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    ISSN: 1573-1561
    Keywords: Cellulases ; xylophagy ; cellulolysis ; acquired enzymes ; nutritional ecology ; Monochamus marmorator ; Trichoderma harzianum ; Coleoptera ; Cerambycidae ; Moniliaceae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Larvae of the balsam fir sawyer,Monochamus marmorator Kby. (Coleoptera, Cerambycidae), contain midgut digestive enzymes active against hemicellulose and cellulose. Cellulases from larvae fed on balsam fir wood infected with the fungus,Trichoderma harzianum Rifai (Deuteromycetes, Moniliales, Moniliaceae), were found to be identical to those of the cellulase complex produced by this fungus when compared using chromatography, electrophoresis, and isofocusing. When larvae are maintained on a fungus-free diet, their midgut fluids lack cellulolytic activity, and they are unable to digest cellulose. Cellulolytic capacity can be restored by feeding the larvae wood permeated by fungi. We conclude that the enzymes which enableM. marmorator larvae to digest cellulose are not produced by the larvae. Instead, the larvae acquire the capacity to digest cellulose by ingesting active fungal cellulases while feeding in fungus-infected wood.
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    Coevolutionary adaptations of rootworm beetles (Coleoptera: Chrysomelidae) to cucurbitacins (1986)
    Springer
    Journal of chemical ecology 12 (1986), S. 1109-1124 
    Details
    ISSN: 1573-1561
    Keywords: Rootworm beetle ; Diabrotica spp ; Aulacophora spp ; Coleoptera ; Chrysomelidae ; Cucurbita spp ; Cucumis spp ; cucurbitacin, allomone ; kairomone ; Chinese mantis ; Tenodera aridifolia sinensis ; predator ; Orthoptera ; Mantidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The cucurbitacins are oxygenated tetracyclic triterpenoids produced as secondary plant compounds by nearly all genera of Cucurbitaceae. The very bitter and toxic cucurbitacins are effective semiochemicals acting ecologically as allomones to protect the Cucurbitaceae from attack by a variety of invertebrate and vertebrate herbivores. For the Luperini (Coleoptera: Chrysomelidae: Galerucinae) the cucurbitacins have become kairomones for host selection, affecting the behavior of this large group of 1500 species of Aulacophorina (Old World) and Diabroticina (New World) by arrest and compulsive feeding. When feeding on bitter cucurbits these beetles sequester large amounts of cucurbitacins in their blood and tissues, and these act as allomones to deter predation. Specific detoxification and excretory mechanisms of the Diabroticina enable these beetles to avoid the toxic effects of the cucurbitacins.
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    Hauptgruppenelement-Übergangsmetall-Mehrfachbindungen, IV. Katalytische Assistenz von [Cp(CO)3Mo]2 bei der Aggregation von Metallo-arsanen über Arsen-Metall-Doppelbindungskomplexe (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 378-382 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Main Group Element Transition Metal Multiple Bonds, IV. Catalytic Assistance by [Cp(CO)3Mo]2 in the Aggregation of Metallo-arsanes via Arsenic Metal Double Bond Complexes2)The metallo-arsanes Cp(CO)3M—AsMe2 (1a, b) (M = Mo, W) are converted to the double arsenido-bridged dinuclear complexes [(μ-AsMe2)Mo(CO)2Cp]2 (3a, b) in the presence of [Cp(CO)3Mo]2. Due to the unusual mild conditions of aggregation the intermediate formation of the double bonded species Cp(CO)2M=AsMe2 (2a, b) is postulated. The crystal structure of 3a is reported, which shows mutual trans arrangement of the cyclopentadienyl and CO ligands.
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    URL: http://dx.doi.org/10.1002/cber.19861190133
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    Aliphatische Flüssigkristalle, 7. Einige mesogene Tercyclohexylderivate (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 387-400 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Aliphatic Liquid Crystals, 7. Some Mesogenic Tercyclohexyl DerivativesStarting from bicyclohexyl-4-one 1 the tercyclohexyl-3-one 6 is synthesized via the acetyl derivatives 3a,b. Methoxycarbonylation of 6 gives the keto ester 12 which on the one hand is tranformed to the esters 15a,b and 17 - 20 and the nitriles 21a,b, on the other hand to the methylated keto esters 23a,b and 24a,b. From 23a the ester 26 with an axial 1-methyl group is obtained. Nearly all the products are mesogenic.
    Notes: Aus dem Bicyclohexyl-4-on 1 wird über die Acetylderivate 3a,b das Tercyclohexyl-3-on 6 aufgebaut, daraus durch Methoxycarbonylierung der Ketoester 12, der einerseits zu den Estern 15a,b und 17 - 20 und den Nitrilen 21a,b, andererseits zu den methylierten Ketoestern 23a,b und 24a,b umgesetzt wird. Aus 23a erhält man den Ester 26 mit axialer 1-Methylgruppe. Fast alle Produkte sind mesogen.
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    URL: http://dx.doi.org/10.1002/cber.19861190202
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    Beiträge zur Chemie des Bors, 169. Sterisch anspruchsvolle N-Lithioaminoborane: Reagentien zur Synthese symmetrisch und unsymmetrisch substituierter Diborylamine (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 1361-1373 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Chemistry of Boron, 169. Sterically Demanding N-Lithioaminoboranes: Reagents for the Synthesis of Symmetrically and Unsymmetrically Substituted DiborylaminesN-Metalation of R2BNH2 or R2BNMeH yields lithium amides R2BNR′Li with sterically demanding R groups (R = tBu, iPr). These compounds are synthons for symmetrically or unsymmetrically substituted diborylamines as well as for B-functional diborylamines. NMR data reveal the conformation of these diborylamines. Compounds of the type tBu2B—NMe—BR2 contain tBu2B groups whose BC2 plane stands nearly orthogonal to the B2NC skeleton. In contrast, the BRX group in diborylamines of the type tBu2B—NH—BRX is strongly twisted with respect to the B2NH plane.
    Notes: Durch N-Metallierung erhältliche Lithiumamide R2BNR′Li mit sperrigen Substituenten R = tBu, iPr eignen sich sowohl zur Darstellung symmetrisch und unsymmetrisch substituierter Diborylamine als auch zur Gewinnung B-funktioneller Diborylamine. Kernresonanzspektroskopische Untersuchungen zeigen, daß Diborylamine tBu2B—NMe—BR2 eine tBu2B-Gruppe enthalten, deren BC2-Ebene weitgehend orthogonal zur B2NC-Gerüstebene steht. In Diborylaminen tBu2B—NH—BRX ist hingegen die BRX-Gruppe gegen die B2NH-Ebene verdrillt.
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    URL: http://dx.doi.org/10.1002/cber.19861190423
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    Mehrfachbindungen zwischen Hauptgruppenelementen und Übergangsmetallen, XXV. Aufbau und Reaktivität von Se1- und Se2-Brücken in Organochrom-Komplexen (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 1437-1440 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Multiple Bonds Between Main Group Elements and Transition Metals, XXV. Synthesis and Reactivity of Se1- and Se2-Bridges in Organochromium CompoundsReaction of the ionic complex K[(η5-C5Me5)Cr(CO)3] (1) with selenium(I) with selenium(I) chloride, Se2Cl2, yields the diselenium compounds 2 of composition (η5-C5Me5)Cr(CO)5Se2 which is converted to the Se1 derivative (μ-Se)[η5-C5Me5)Cr2(CO)2]2 (3) with triphenylphosphane. 3 exhibits a linear, multiple bonded CrSeCr core structure. Reaction of 2 with diazomethane gives the novel mononuclear, paramagnetic selenoformaldehyde complex (η5-C5Me5)-Cr(CO)2(SeCH2) (4).
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    Masthead (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986) 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19861190501
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    N-tert-Butylpivalohydroxamsäure: s-trans-Konformation und H-Brückenbindungen im Kristall (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 1441-1444 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: N-tert-Butylpivalohydroxamic Acid: s-trans-Conformation and H-Bonding in the CrystalIt is shown by an X-ray crystal structure analysis that, in the crystal, teh title compound has the s-trans-conformation and the molecules are linked by strong intermolecular H-bonds to linear chains.
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    URL: http://dx.doi.org/10.1002/cber.19861190431
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    Synthesen von 2,6,7-Triazabicyclo[2.2.2]oct-2-en-5,8-dionen und 4(3H)-Pyrimidinonen durch 1,4-Dipolare Cycloadditionen von Pyrimidinium-4-olaten an Nitrile (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 1445-1454 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses of 2,6,7-Triazabicyclo[2.2.2]oct-2-ene-5,8-diones and 4(3H)-Pyrimidinones via 1,4-Dipolar Cycloaddition Reactions of Pyrimidinium-4-olates to NitrilesThe 3,6-dihydro-6-oxo-1-pyrimidinium-4-olate 1a, which carry no substituent in the 2 position, undergoes 1,4-dipolar cycloaddition reactions with ethyl cyanoformate (2a) and benzoyl cyanide (2b) to produce novel bicyclic primary adducts 3a, b, respectively, which at higher temperature fragment into 4(3H)-pyrimidinones 4a, b with elimination of phenyl isocyanate. However, pyrimidinium-4-olates 1b - h or 5, which are substituted in the 2 position, react directly with nitriles 2a - c to form high yields of 4(3H)-pyrimidinone derivatives of type 4 or 7, respectively. Furthermore, the reactions of 1a with isocyanic acid as well as with cyan amide are described.
    Notes: Das in 2-Position unsubstituierte 3,6-Dihydro-6-oxo-1-pyrimidinium-4-olat 1a geht mit Cyanameisensäure-ethylester (2a) und Benzoylcyanid (2b) 1,4-Dipolare Cycloadditionen zu neuen bicyclischen Primäraddukten 3a bzw. b ein, die bei höherer Temperatur unter Phenylisocyanat-Abgabe in 4(3H)-Pyrimidinone 4a, b fragmentieren. Dagegen reagieren die in 2-Stellung substituierten Pyrimidinium-4-olate 1b - h oder 5 mit Nitrilen 2a - c in hohen Ausbeuten direkt zu den 4(3H)-Pyrimidinon-Derivaten vom Typ 4 bzw. 7. Weiterhin werden die Reaktionen von 1a mit Isocyansäure sowie mit Cyanamid beschrieben.
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    Über sterisch gehinderte freie Radikale, XV. Das erste unsymmetrische Dimere aus zwei stabilen Radikalen: 3-(tert-Butylphenylmethylen)-6-(triphenylmethyl)-1,4-cyclohexadien aus tert-Butyldiphenylmethyl und Triphenylmethyl (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2006-2012 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Sterically Hindered Free Radicals, XV. The First Unsymmetrical Dimer from Two Different Stable Radicals: 3-(tert-Butylphenylmethylene)-6-(triphenylmethyl)-1,4-cyclohexadiene from tert-Butyldiphenylmethyl and TriphenylmethylThe quinonoid title compound 6 is formed in an equilibrium to 95% and can be isolated, when the two title radicals 1 and 3 are generated in solution. The reason for this is the sterically less strained position of the bulky tBu group at the sp2-C atom of the methylene group. The structure of 6 is proved by 1,5-H migration giving 8 and autoxidation of the latter at -10°C giving tBuOH and 4-tritylbenzophenone (12). The synthesis of several analogous compounds are described.
    Notes: Die chinoide Titelverbindung 6 entsteht im Gleichgewicht zu 〉95% und kann isoliert werden, wenn die beiden Titelradikale 1 und 3 in Lösung erzeugt werden. Ursache hierfür ist die räumlich günstigere Unterbringung der sperrigen tBu-Gruppe am sp2-C-Atom der Methylengruppe. Die Struktur von 6 wird durch 1,5-H-Verschiebung zu 8 sowie dessen Autoxidation bei -10°C zu tBuOH und 4-Tritylbenzophenon (12) bewiesen. Synthesen analoger Verbindungen werden beschrieben.
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    URL: http://dx.doi.org/10.1002/cber.19861190621
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    Der Einfluß von Phenylgruppen auf die Homokonjugation im Bicyclo[3.2.1]octa-3,6-dien-2-yl-Anion. Eine 13C-NMR-Studie (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2025-2049 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Effect of Phenyl Groups on the Homoconjugation in the Bicyclo[3.2.1]octa-3,6-dien-2-yl Anion. A 13C NMR StudyThe effects of deuterium atoms in the positions 2 and 4 of exo-6-bromo- (11) and endo-6-methoxytricyclo[3.2.1.02,7]oct-3-ene (12) as well as exo-4-methoxybicyclo[3.2.1]octa-2,6-diene (13) on their 13C chemical shifts are in line with the previous interpretation of the effects in correspondingly deuterated bicyclo[3.2.1]octa-3,6-dien-2-yl anions 1, and thus provide evidence for the homoconjugative interaction in 1. 3-Phenylbicyclo[3.2.1]octa-2,6-diene (16) and endo- (19a) as well as exo-4-phenylbicyclo[3.2.1]octa-2,6-diene (19b) have been prepared from bicyclo[3.2.1]oct-6-en-3-one (14) and bicyclo[3.1.0]hex-2-ene-endo-6-carbaldehyde (17), respectively. 2,4-Diphenylbicyclo[3.2.1]octa-2,6-diene (6) and 19a, b were deprotonated by methyllithium and n-butyllithium, respectively, whereas the proton abstraction from tricyclo[6.3.1.02,7]dodeca-2,4,6,9-triene (4) and from 16 required potassium tert-butoxide/n-butyllithium. As products the corresponding bicyclo[3.2.1]octa-3,6-dien-2-yl anion derivatives have been identified. By means of potassium tert-butoxide/n-butyllithium 19a, b were converted into 21K, i.e. the anion with K+ as counterion. The NMR spectra of 21Li turned out to depend upon the temperature in the range between +45 and -30°C in contrast to those of 21K. The 13C NMR spectra of the anions and of the corresponding hydrocarbons are discussed in detail in relation to the spectra of the unsubstituted species 1 and 2. In particular, the wide variations of the chemical shifts of C-6,7 depending upon the substituents of the allylic moiety of the bicyclo[3.2.1]octa-3,6-dien-2-yl anion system give strong support for the bishomoaromatic nature of these anions.
    Notes: Die Effekte von Deuteriumatomen in den Positionen 1 und 4 von exo-6-Brom- (11) und endo-6-Methoxytricyclo[3.2.1.02,7]oct-3-en (12) sowie exo-4-Methoxybicyclo[3.2.1]octa-2,6-dien (13) auf deren 13C-chemische Verschiebungen stützen die frühere Interpretation der Effekte bei entsprechend deuterierten Bicyclo[3.2.1]octa-3,6-dien-2-yl-Anionen 1 und belegen so die homokonjugative Wechselwirkung in 1.  -  Ausgehend von Bicyclo[3.2.1]oct-6-en-3-on (14) und Bicyclo[3.1.0]hex-2-en-endo-6-carbaldehyd (17) stellte man 3-Phenyl- (16) bzw. endo-4-Phenyl-(19a) und exo-4-Phenylbicyclo[3.2.1]octa-2,6-dien (19b) dar. 2,4-Diphenylbicyclo[3.2.1]octa-2,6-dien (6) und 19a, b wurden mit Methyllithium bzw. n-Butyllithium, Tricyclo[6.3.1.02,7]dodeca-2,4,6,9-tetraen (4) sowie 16 mit Kalium-tert-butoxid/n-Butyllithium deprotoniert, wobei die entsprechenden Bicyclo[3.2.1]octa-3,6-dien-2-yl-Anionderivate 7, 21Li, 5 und 22 entstanden. Aus 19a, b wurde mit Kalium-tert-butoxid/n-Butyllithium auch 21K, d. h. das zugehörige Anion mit K+ als Gegenion erhalten. Die NMR-Spektren von 21Li erwiesen sich im Gegensatz zu jenen von 21K im Bereich von +45 bis -30°C als temperaturabhängig. Die 13C-NMR-Spektren der Anionen und der zugehörigen Kohlenwasserstoffe werden im Vergleich mit den Spektren der unsubstituierten Verbindungen 1 und 2 ausführlich diskutiert. Insbesondere die starken Variationen der chemischen Verschiebungen von C-6,7 in Abhängigkeit von den Substitutenten am Allylteil des Bicyclo[3.2.1]octa-3,6-dien-2-yl-Anionsystems bieten ein starkes Argument für die bishomoaromatische Natur dieser Anionen.
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    Synthese und physikalische Eigenschaften neuer 1,3-Dithiolylium-4-methanide und 1,3-Thiazolium-5-methanide (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2094-2103 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Physical Properties of Novel 1,3-Dithiolylium-4-methanides and 1,3-Thiazolium-5-methanidesThe synthesis and physical properties of the novel title compounds of type 9 from carboxylic acid derivatives 3 and CH acidic compounds 4 are described.
    Notes: Die Synthese und physikalischen Eigenschaften der neuen Titelverbindungen vom Typ 9 aus Carbonsäure-Derivaten 3 und CH-aciden Verbindungen 4 werden beschrieben.
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    URL: http://dx.doi.org/10.1002/cber.19861190704
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    Metallaheterocumulene, IV. 2-Azaallyliden-Komplexe  -  neuartige Verbindungen mit einem gewinkelten CNCR2-Fragment als Komplexligand (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2080-2093 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Metallaheterocumulenes, IV. 2-Azaallylidene Complexes  -  Novel Compounds with a Bent CNCR2 Fragment as Complex Ligand(2-Azoniaallenylidene)pentacarbonyltungsten tetrabromoaluminate complexes [(CO)5W(CNCR2)]+AlBr4- (2-AlBr4) (CR2=C(C6H4Br-4)2 (a), CPh2 (b), C(C6H4OMe-4)2 (c), C(C6H4)2O (d), C(2,4,6-C6H2Me3)2 (e)) Which are synthesized by the reaction of (CO)5W[C(OEt)N=CR2] (1) with AlBr3, react with freshly distilled tetrahydrofuran to give neural trans-bromo(2-azaallylidene) complexes trans-Br(CO)4W(CNCR2) (3) and small amounts of (CO)5W—C≡N—[CR2]2—N≡C—W(CO)5 (4). The compounds 4 correspond to the product of a reductive dimerization of two cations 2. If 1b (or the corresponding methoxy compound 5) reacts with BBr3 instead of AlBr3/THF 4b is the main product. The spectroscopic data of 3 and the results of an X-ray analysis of 3b show that the replacement of a CO ligand in the cations 2 by Br- with formation of 3 results in a drastic change of the bonding situation within the CNCR2 ligand. 3a-e are the first compounds in which a strongly bent CNCR2 fragment functions as a complex ligand. The aminocarbyne complex trans-Br(CO)4W≡CNPh2 (7) was synthesized by BBr3-induced fragmentation of (CO)5W[C(NPh2)N=C(Ph)OMe] (6).
    Notes: (2-Azoniaallenyliden)pentacarbonylwolfram-tetrabromoaluminat-Komplexe [(CO)5W(CNCR2)]+AlBr4- (2-AlBr4) (CR2=C(C6H4Br-4)2 (a), CPh2 (b), C(C6H4OMe-4)2 (c), C(C6H4)2O (d), C(2,4,6-C6H2Me3)2 (e))  -  darstellbar durch Umsetzung von (CO)5W[C(OEt)N=CR2] (1) mit Albr3  -  reagieren mit frisch destillierten Tetrahydrofuran zu neutralen trans-Bromo(2-azaallyliden)-Komplexen trans-Br(CO)4W(CNCR2) (3) und wenig (CO)5W—C≡N—[CR2]2—N≡C—W(CO)5 (4). Die Verbindungen 4. entsprechen dem Produkt einer reduktiven Dimerisierung zweier Kationen 2. 4b wird zum Hauptprodukt der Umsetzung, wenn 1b (oder der entsprechende Methoxy-Komplex 5) mit BBr3 anstatt AlBr3/THF umgesetzt wird. Wie die spektroskopischen Daten von 3 sowie die Ergebnisse der an 3b durchgeführten Röntgenstrukturanalyse zeigen, führt der Austausch eines CO-Liganden in den Kationen 2 gegen Br- unter Bildung von 3 zu einer drastischen Veränderung der Bindungsverhältnisse im CNCR2-Liganden. 3a-e sind die ersten Verbindungen, in denen ein stark gewinkeltes CNCR2-Fragment als Komplexligand fungiert. Durch BBr3-induzierte Fragmentierung von (CO)5W[C(NPh2)N=C(Ph)OMe] (6) wurde der Aminocarbin-Komplex trans-Br(CO)4W≡CNPh2 (7) dargestellt.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19861190703
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  • 52
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    Heterocyclische β-Enaminoester, 41. Vinylogieprinzip bei 6,7-Dihydro-1H-azepinen; Cycloaddition und neuartige Umlagerung zu 2,3,3a,7a-Tetrahydroindolen.  -  Thermische [2 + 2]-Cycloadditionen mit 4-R-TAD (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2114-2126 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Heterocyclic β-Enamino Esters, 41. Vinylogeous Principle on 6,7-Dihydro-1H-azepines; Cycloaddition and Novel Rearrangement to 2,3,3a,7a-Tetrahydroindoles.  -  Thermal [2 + 2]-Cycloadditions with 4-R-TADThe conjugated π-Systems of 6,7-dihydrooxepines, -thiepines, and -azepines (1-5) show a remarkable alternance of their 13C NMR shifts. In a cycloaddition-ring enlargement sequence the 6,7-dihydroazepine 3 reacts with acetylenedicarboxylates at the 4,5-double bond to afford first the intermediary 8,9-dihydro-1H-azonines 6B. These give in turn the indoles 7a,b via thermal 6π-electron cyclization. Under subsequent rearrangement 2,3,3a,7a-tetrahydroindoles 8a,b are formed. The structure of 8a is established by X-ray diffraction. In a polar [2 + 2]-cycloaddition 4-R-1,2,4-triazoline-3,5-dione (4-R-TAD) gives with 3 and 5 the [1,2,4]triazolo[1′,2′:1,2]diazet-[3,4-d]azepines 10a-d and 11a,b resp., and with the bis-TAD 12 the 2:1-adduct 13. Treatment of 10a with phenyl isocyanate originates the carbodiimide 14 which is converted with basic ring closure into the pyrimido[4,5-b]azepine 15.
    Notes: 6,7-Dihydrooxepine, -thiepine und -azepine (1-5) zeigen eine ausgeprägte Alternanz ihrer 13C-NMR-Verschiebungen im konjugierten π-System. Das 6,7-Dihydroazepin 3 reagiert mit Acetylendicarbonsäureestern zunächst unter Cycloaddition-Ringerweiterung an der 4,5-Doppelbindung zu den intermediären 8,9-Dihydro-1H-azoninen 6b. Diese ergeben sogleich unter thermischem 6π-Elektronenringschluß die Indole 7a,b. Nach erneuter Umlagerung entstehen 2,3,3a,7a-Tetrahydroindole 8a,b; die Konstitution von 8a wird durch Röntgenstrukturanalyse ermittelt. Mit 4-R-1,2,4-Triazolin-3,5-dionen (4-R-TAD) entstehen aus 3 und 5 in polarer [2 + 2]-Cycloaddition die [1,2,4]Triazolo[1′,2′:1,2]diazet[3,4-d]azepine 10a-d und 11a,b mit dem Bis-TAD 12 das 2:1-Addukt 13. 10a ergibt mit Phenylisocyanat das Carbodiimid 14 und beim basischen Ringschluß das Pyrimido[4,5-b]azepin 15.
    Additional Material: 5 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19861190706
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    Neue Reagenzien, XXXVII. (α-Lithioalkyl)diphenylarsanoxide: Synthese und Anwendung zur indirekten nucleophilen Haloalkylierung (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2135-2142 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: New Reagents, XXXVII. (α-Lithioalkyl)diphenylarsane Oxides: Synthesis and Application for the Indirect Nucleophilic HaloalkylationDue to ready accessibility and high nucleophilicity (α-lithioalkyl)diphenylarsane oxides (2) are favorable reagents for the synthesis of many organoarsenic compounds. In organic synthesis they are recommendable as reagents for indirect nucleophilic haloalkylation reactions (Hal=Cl, Br, I).
    Notes: (α-Lithioalkyl)diphenylarsanoxide (2) sind wegen ihrer bequemen Zugänglichkeit und hohen Nucleophilie günstige Reagenzien zur Darstellung zahlreicher Organoarsenverbindungen. In der organischen Synthese sind sie als Reagenzien für indirekte nucleophile Haloalkylierungen (Hal=Cl, Br, I) empfehlenswert.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19861190708
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  • 54
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    Synthesen mit Cyclobutadienen, 13. Azapentafulvene aus 2,3,4-Tri-tert-butylcyclobutadien-1-carbonsäureestern und Isonitrilen (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2159-2172 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthese with Cyclobutadienes, 13. Azapentafulvenes from 2,3,4-Tri-tert-butylcyclobutadiene-1-carboxylic Esters and IsonitrilesFrom kinetically stabilized cyclobutadienes 6a and b and isonitriles 7a-c the azapentafulvenes 9a-d are obtained. In contrast, 6a reacts with 7d exclusively to form the constitution isomeric azapentafulvene 11e. Both isomers (9f and 11f) are realized in the reaction of 6a with 7e. The structural assignment of the isomers 9 and 11 is based on 13C NMR investigations as well as on an X-ray analysis performed for 9a. Hydrolysis of 9 and 11 yields the tri-tert-butyl substituted cyclopentadienones 20a,b and 21. By photochemical means 21 is transformed into the isomer 20a, which can also be obtained directly from the cyclobutadiene 6a and carbon monoxide.
    Notes: Aus den kinetisch stabilisierten Cyclobutadienen 6a bzw. b und den Isonitrilen 7a-c erhält man die Azapentafulvene 9a-d. Im Gegensatz dazu reagiert 6a mit 7d ausschließlich unter Bildung des konstitutionsisomeren Azapentafulvens 11e. Beide Möglichkeiten (9f und 11f) werden bei der Umsetzung von 6a mit 7e wahrgenommen. Die Strukturzuordnung der Isomeren 9 und 11 beruht auf 13C-NMR-Untersuchungen sowie auf der Röntgenstrukturanalyse für 9a. Hydrolyse von 9 und 11 macht die tri-tert-butylsubstituierten Cyclopentadienone 20a,b und 21 zugänglich. Photochemisch läßt sich 21 in das Isomere 20a umwandeln, das auch unmittelbar aus dem Cyclobutadien 6a und Kohlenmonoxid erhalten werden kann.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19861190711
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    Enantioselective diastereospecific synthesis of anti-α-alkyl-β-hydroxy esters through cuprate opening of glycidic esters (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2178-2190 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Enantioselektive diastereospezifische Synthese von anti-α-Alkyl-β-hydroxycarbonsäureestern durch Cuprat-Ringöffnung von GlycidesternEine über die Zwischenglieder 4-7 ablaufende diastereospezifische Kettenverlängerung von Aldehyden 1 zu anti-α-Alkyl-β-hydroxyestern 2 wird beschrieben. Durch Verwendung der Sharpless-Epoxidierung kann 2 mit Enantiomerenüberschüssen von 〉90% in Form beider Antipoden erhalten werden.
    Notes: A diastereospecific chain elongation of the aldehydes 1 of anti-α-alkyl-β-hydroxy esters 2 via the intermediates 4-7 is described. By means of the Sharpless epoxidation, 2 may be obtained with 〉90% ee in either enantiomer.
    Additional Material: 4 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19861190713
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  • 56
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    Stereoselektive Aldolreaktion mit chiralen sekundären Acetamiden (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2191-2207 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stereoselective Aldol Reaction with Chiral Secondary AcetamidesThe deprotonated acetamides 4a-c und 5a-c are added to prochiral carbonyl compounds. The influence of the solvent, of the reaction temperature, and of the enolate gegenion on the ratio of the isomeric products 8/9, 18/19, and 26/27, respectively, are studied. The highest degrees of diastereoselectivity are observed, when the titanium enolate of the acetamide 4a or the threefold deprotonated N-acetyl-α-phenylglycinol (5a) is used. The diastereomers 18a-d, formed in excess in the addition of 5a to aldehydes, are isolated in a pure form by a single recrystallization, and afford the enantiomerically pure β-hydroxy carboxylic acids 3a-d. Thereby, the chiral auxiliary, α-phenylglycinol (14), is recovered.
    Notes: Die deprotonierten Acetamide 4a-c und 5a-c werden an prochirale Carbonylverbindungen addiert. Dabei wird der Einfluß von Lösungsmittel, Temperatur und Enolat-Gegenion auf das jeweilige Verhältnis der isomeren Produkte 8/9, 18/19 und 26/27 untersucht. Die höchsten Diastereoselektivitäten lassen sich mit dem Titan-enolat des Amids 4a und dem dreifach deprotonierten N-Acetyl-α-phenylglycinol (5a) erzielen. Die bei der Addition von 5a an Aldehyde im Überschuß gebildeten Diastereomeren 18a-d können durch einmaliges Umkristallisieren rein erhalten werden und liefern nach alkalischer Hydrolyse die enantiomerenreinen β-Hydroxycarbonsäuren 3a-d. Dabei wird der chirale Hilfsstoff, α-Phenylglycinol (14), zurückgewonnen.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19861190714
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    Synthesis of ketene aminals with an imidazolidine ring by condensation of 4,5-dihydro-2-(methylithio)-1H-imidazoles with active methylene compounds and some addition and cyclocondensation reactions (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2208-2219 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthese von Ketenaminalen mit Imidazolidinring durch Kondensation von 4,5-Dihydro-2-(methylthio)-1H-imidazolen mit CH-aciden Methylenverbindungen und einige Additions-und Cyclokondensations-Reaktionen4,5-Dihydro-2-(methylthio)-1H-imidazole 1a, b reagieren mit aktiven Methylenverbindungen 2a-f unter Eliminierung von Methanthiol zu den entsprechend substituierten Methylenimidazolidinen 3a-f und 4c-f. Die Verbindungen 2g-j, die eine aktivere Carbonylgruppe enthalten, ergeben mit 1a unter Eliminierung einer Methylthio- und Acylgruppe 3g-i. 3a, g-i reagieren mit Estern ungesättigter Säuren in einer Additions- und Cyclokondensations-Sequenz zu den entsprechenden Imidazo[1,2-a]pyridinen 5,6 und 7, ergeben aber mit Azodicarbonsäure-diethylester nur die Additionsprodukte 8.
    Notes: The 4,5-dihydro-2-(methylthio)-1H-imidazoles 1a,b react with active methylene compounds 2a-f to afford the corresponding substituted methyleneimidazolidines 3a-f and 4c-f by elimination of methanethiol. The reaction of compounds 2g-j, which contain a more active carbonyl group, with 1a gives 3g-i by elimination of a methylthio group as well as an acyl group, too. 3a,g-i react with esters of α,β-unsaturated acids to afford the corresponding imidazo[1,2-a]pyridines 5,6, and 7 in an addition and cyclocondensation reaction sequence, but with diethyl azodicarboxylate only to give the addition product 8.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19861190715
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    Desaminierungsreaktionen, 43. Zum Einfluß von Trifluormethylgruppen auf die Reaktionen aliphatischer Diazonium-Ionen und Carbokationen (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2233-2248 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Deamination Reactions, 43. The Effect of Trifluoromethyl Groups on the Reactivity of Aliphatic Diazonium Ions and CarbocationsVarious trifluoroalkanamines (9, 26, 35, 38, 45, 56, and 67) have been prepared and diazotized (water, pH 3.5) to probe the effect of trifluoromethyl groups on the reactivity of aliphatic diazonium ions. The product distributions reveal that α-CF3 groups enhance inverting displacement and enforce rearrangements (hydride shifts) separating the positive charge from CF3. Migrations of the positive charge from the β- to the γ-position are less strongly promoted than those from α to β. Enhancement factors of ca. 15 (α → β) and 4 (β → γ) may be derived by comparison with analogous alkanediazonium ions. The positive charge does not migrate in the reverse direction (β → α) except for minor amounts of a pinacolic rearrangement (68 → 7). A migration of the positive charge from γ to β has been detected with 36 but a tenfold decrease as compared to the analogous butanediazonium ion 37 is indicated. All observations are reasonably explained in terms of the relative stabilites of the intermediate trifluoroalkyl cations.
    Notes: Eine Reihe von Trifluoralkanaminen (9, 26, 35, 38, 45, 56 und 67) wurde dargestellt und diazotiert (Wasser, pH 3.5), um den Einfluß von Trifluormethylgruppen auf die Reaktionsweise aliphatischer Diazonium-Ionen zu untersuchen. Die Produktverteilungen zeigen, daß α-CF3-Gruppen die invertierende Substitution verstärken und Umlagerungen (Wasserstoffverschiebungen) fördern, welche die positive Ladung von der CF3-Gruppe trennen. Die Wanderung der positiven Ladung von der β- zur γ-Position wird weniger stark gefördert als die von α nach β. Aus dem Vergleich mit analogen Alkandiazonium-Ionen lassen sich Beschleunigungsfaktoren von ca. 15 (α → β) und 4 (β → γ) ableiten. In umgekehrter Richtung (β → α) wandert die positive Ladung nicht, abgesehen von einem kleinen Anteil Pinakol-Umlagerung (68 → 7). Eine Ladungsverschiebung von der γ- zur β-Position wurde bei 36 gefunden; im Vergleich zum analogen Butandiazonium-Ion 37 ist sie um den Faktor 10 verringert. Alle Beobachtungen sind im Einklang mit der relativen Stabilität der intermediären Trifluoralkyl-Kationen.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19861190717
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    Neuartige 2,6-disubstituierte Azulene (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2272-2288 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Novel 2,6-Disubstituted AzulenesMethods are described to introduce varying residues into 2- and 6-positions of azulene, starting from diethyl 6-bromo-2-methoxy-1,3-azulenedicarboxylate (1). 2-Substitution is achieved by Grignard reaction or exchange of the alkoxy group and by aldol condensation of 2-methyl compounds whereas 6-substitution is conducted by nucleophilic displacement and by homo- and hetero-aromatic coupling. Consecutive dealkoxycarbonylation yields azulenes 20 with free 1,3-positions. Biazulenes 9a-c and 201, 20m, styryl- and bis(styryl)-azulenes 15-18 and 20i-k, and finally the azulenedialdehyde 19 are novel compounds which were difficult to prepare or were inaccessible so far.
    Notes: Ausgehend von 6-Brom-2-methoxy-1,3-azulendicarbonsäure-diethylester (1) werden Methoden zur Einführung unterschiedlicher Reste in 2- und 6-Position entwickelt. 2-Substitution gelingt durch Grignard-Reaktion oder Austausch der Alkoxygruppe sowie durch Aldol-Kondensation von 2-Methylverbindungen, während 6-Substitution durch nucleophilen Austausch und durch Homo- und Kreuz-Aromaten-Kupplungen erfolgt. Anschließende Dealkoxycarbonylierung erbringt Azulene 20 mit freien 1,3-Stellungen. Die Biazulene 9a-c und 201, 20m, die Styryl- und Bis(styryl)azulene 15-18 und 20i-k sowie der Azulendialdehyd 19 sind Verbindungen, die bisher schwierig oder nicht zugänglich waren.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19861190720
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    Zur Frage der Stellungsisomerie bei disubstituierten Bullvalenen (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2339-2349 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Concerning the Question of Positional Isomerism in Disubstituted BullvalenesWe report about 15 new disubstituted bullvalenes (2, 4, 5, 11, 12, 14-20, 22-24) and discuss their substitution pattern together with 9 known species (1, 3, 6-10, 13, 21). The results which are partly unexpected are put together phenomenologically. We have no reasonable explanation for some results, i.e. only a few substituents with „complementary“ properties like the pair CH2OH/Br or CH3/CN in compounds 16 and 18, respectively, prefer a vicinal arrangement at a double bond.
    Notes: Wir berichten über 15 neue disubstituierte Bullvalene (2, 4, 5, 11, 12, 14-20, 22-24) und diskutieren ihr Substitutionsmuster gemeinsam mit dem von 9 bekannten Vertretern (1, 3, 6-10, 13, 21). Die teilweise unerwarteten Ergebnisse werden phänomenologisch geordnet. Für einige Befunde fehlen befriedigende Erklärungen. So bevorzugen z. B. nur manche Substituenten mit „komplementären“ Eigenschaften wie das Paar CH2OH/Br oder CH3/CN in den Verbindungen 16 bzw. 18 eine vicinale Anordnung an der Doppelbindung.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19861190724
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    Zur Regio- und Stereoselektivität neuer thermischer [3 + 2]-Cycloadditionen mesoionischer 1,3-Oxathiol-4-one an Alkine und Alkene (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2317-2338 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Regio- and Stereoselectivity of Novel Thermal [3 + 2] Cycloaddition Reactions of Mesonionic 1,3-Oxathiol-4-ones to Alkynes and AlkenesAs potential carbonyl ylides, the 1,3-oxathiolyium-4-olates 1c or 1d combine with dibenzoylacetylene or 1-(diethylamino)-1-propyne via nonisolable [3 + 2] primary adducts of type 2, which release COS to give the furan derivatives 3a or b, respectively. On the other hand, some representative of 1 reacts with symmetrically and unsymmetrically substituted olefinic substrates with regio- and/or stereoselective formation of the isolable [3 + 2] primary adducts 4-16. In the example of the reactions of 1c with trans- and cis-cyclooctene, the stereospecificities and the competition constant are determined. Furthermore, the thermolyses of the cycloadducts 4b,5,6, and 7a,b are investigated. The addition directions, derived from the FMO and PMO theory, are compared with the experimentally realized regiochemistry.
    Notes: Als potentielle Carbonyl-ylide vereinigen sich die 1,3-Oxathiolylium-4-olate 1c oder 1d mit Dibenzoylacetylen oder 1-(Diethylamino)-1-propin über nicht isolierbare [3 + 2]-Primäraddukte vom Typ 2 unter COS-Abspaltung zu Furan-Derivaten 3a bzw. b. Demgegenüber reagieren einige Vertreter von 1 mit symmetrisch und unsymmetrisch substituierten olefinischen Substraten regio- und/oder stereoselektiv zu isolierbaren [3 + 2]-Primäraddukten 4-16. Am Beispiel der Umsetzung von 1c mit trans- und cis-Cycloocten werden die Stereospezifitäten und die Konkurrenzkonstante ermittelt. Weiterhin werden die Thermolysen der Cycloaddukte 4b, 5, 6 und 7a,b untersucht. Die aus der FMO- und PMO-Theorie abgeleiteten Additionsrichtungen werden mit der experimentell realisierten Regiochemie verglichen.
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    URL: http://dx.doi.org/10.1002/cber.19861190723
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    Synthese und Reaktion von α-(Dimethylamino)alkanaldimethylhydrazonen (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2397-2413 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Reaction of α-(Dimethylamino)alkanal DimethylhydrazonesSeveral α-(dimethylamino)aldehyde hydrazones of the general structure 11 have been obtained by alkylation of the lithium salt of 9 or by addition of Grignard reagents to 15 or 17. The compounds react with acyl chlorides to give hydrazones of unsaturated aldehydes. The same products 27 are obtained by thermal degradation of the ammonium salts 26. In the hydrazonoammonium salts 26a, g the trimethylammonium group can be substituted by a variety of nucleophiles (→ 34-39).
    Notes: Verschieden substituierte α-(Dimethylamino)aldehyd-hydrazone der allgemeinen Struktur 11 lassen sich aus dem Lithium-Salz des (Dimethylamino)acetaldehyd-dimethylhydrazons durch Alkylierung sowie durch Addition von Grignard-Verbindungen an das Ammoniumsalz 15 oder das N,O-Acetal 17 darstellen. Die Verbindungen 11 enthalten eine leicht eliminierbare Dimethylaminogruppe und gehen mit Säurechloriden oder nach Methylierung thermisch in Hydrazone 27 α,β-ungesättigter Aldehyde über. In den Salzen 26a, g läßt sich die Trimethylammoniumgruppe durch verschiedene Nucleophile verdrängen (→ 34-39).
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    Intramolekulare Wechselwirkungen in Radikalkationen von Di- und Tetra(α-methoxy)-9,10-dihydro-9,10-ethanoanthracenen (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2414-2429 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Intramolecular Interactions in Radical Cations of Di- and Tetra(α-methoxy)-9,10-dihydro-9,10-ethanoanthracenes[4 + 2]-Cycloaddition of maleic anhydride, 2-chloropropenoyl chloride and (E)-dichloroethene to 1,4-di- (3a) and 1,4,5,8-tetramethoxyanthracene (3b) yields the dihydroethanoanthracenes 4, 5, and 8, respectively. The predominant maleic anhydride adduct 4a is assigned the exo-configuration on the basis of the ESR spectrum of the radical cations 4a+·. The cycloadducts 5 and 8 are converted to the dihydroethanoanthracenes 10 via the ketones 6 or the dihydroethenoanthracenes 9, respectively. Aluminium chloride in nitromethane oxidizes the α-methoxydihydroethanoanthracenes 4, 6a, 8, and 10 to radical cations the ESR spectra of which are analyzed. Besides the expected proton hyperfine splittings of the 1,4-dimethoxybenzene moiety, one observes long-range transfer of spin density to the unsubstituted benzene ring [a(4H) = 0.008-0.010 mT] as well as to the syn-[10a+·: a(2H) = 0.013 mT] and anti-protons [a(2H) = 0.059-0.069 mT] of the ethano bridge. Of the radical cations possessing two 1,4-dimethoxybenzene rings, 4b and 10b do not exhibit dynamic ESR spectroscopic phenomena. On the other hand, the unpaired electron is exchanged rapidly (with respect to the hyperfine splitting time scala) between the 1,4-dimethoxybenzene rings of the radical cation 8b+·. The dependence of the exchange frequency on the temperature and the aluminium chloride concentration is indicative of ion-pair effects.
    Notes: Durch [4 + 2]-Cycloaddition von Maleinsäureanhydrid, 2-Chlorpropenoylchlorid bzw. (E)-Dichlorethen an 1,4-Di- (3a) und 1,4,5,8-Tetramethoxyanthracen (3b) entstehen die Dihydroethanoanthracene 4, 5 bzw. 8. Dem überwiegenden der Maleinsäureanhydrid-Addukte 4a wird aufgrund des ESR-Spektrums der Radikalkationen 4a+· die exo-Konfiguration zugeordnet. Die Cycloaddukte 5 und 8 werden über die Ketone 6 bzw. Dihydroethenoanthracene 9 in die Dihydroethanoanthracene 10 übergeführt. Aluminiumchlorid in Nitromethan oxidiert die α-Methoxydihydroethanoanthracene 4, 6a, 8 und 10 zu Radikalkationen, deren ESR-Spektren analysiert werden. Neben den erwarteten Protonen-Hyperfeinaufspaltungen des 1,4-Dimethoxybenzolrings beobachtet man weitreichenden Transfer von Spindichte zum unsubstituierten Benzolring [a(4H) = 0.008-0.010 mT] sowie zu den syn-[10a+·: a(2H) = 0.013 mT] und anti-Protonen [a(2H) = 0.059-0.069 mT] der Ethanobrücke. Von den Radikalkationen mit zwei 1,4-Dimethoxybenzolringen zeigen die aus 4b und 10b erhaltenen keine dynamischen ESR-spektroskopischen Phänomene. Dagegen wird in 8b+· das ungepaarte Elektron rasch bezüglich der Hyperfeinaufspaltungs-Zeitskala zwischen den 1,4-Dimethoxybenzolringen ausgetauscht. Die Abhängigkeit der Austauschfrequenz von der Temperatur und der Aluminiumchlorid-Konzentration weist auf Ionenpaar-Effekte hin.
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    Synthesen, Struktur und Eigenschaften von N-(Alkoxymethylen)carbamidsäureestern (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2444-2457 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses, Structures, and Properties of N-(Alkoxymethylene)carbamatesN-(Alkoxymethylene)carbamates 1 are synthesized from the imidate hydrochlorides 7 or from the imidates 8 and formates 9 in the presence of amine bases in mostly satisfactory yields (two optimized procedures, 10 examples).—An X-ray analysis of the derivative 1dbc shows an almost planar EtO—RC=N—C skeleton with an exo-s-cis-ethoxy function; the carboxylic group is nearly perpendicular to that plane.  - Quantum mechanical ab initio optimizations (3-21 G//3-21 G) were performed for nine conformations of the model substances 11; the calculated rotational barrier around the amide type bond is estimated to be ca. 5 kcal/mol. The ground state energy of the conformers of 11 is ca. 20 kcal/mol higher than that of the model for 10, N-formylcarbamic acid (12). —IR, 1H, and 13C NMR data for solutions of 1 are discussed.
    Notes: N-(Alkoxymethylen)carbamidsäureester 1 können durch Umsetzung der Imidsäureester-hydrochloride 7 oder der Imidsäureester 8 mit Chlorameisensäureestern 9 in Gegenwart von Aminbasen in meist guten bis sehr guten Ausbeuten hergestellt werden (zwei optimierte Syntheseverfahren, 10 Beispiele). Schonende Hydrolyse der Verbindungen 1 ergibt die N-Acylcarbamidsäureester 10.  - Die Röntgenstrukturanalyse des Derivates 1dbc zeigt ein planares RO—RC=N—C-Molekülgerüst mit exo-ständiger s-cis-orientierter Ethoxygruppe; die Carboxylgruppe steht annähernd senkrecht auf dieser Ebene.  - Mit Hilfe quantenmechanischer ab-initio-Berechnungen (3-21G//3-21 G) wurden Strukturen und Energien der Modellverbindungen 11 bestimmt und deren Rotationsbarriere um die amidische -Bindung abgeschätzt (ca. 5 kcal/mol). Im Vergleich mit N-Formylcarbamidsäure (12) (Modell für 10) besitzen die Verbindungen 11 eine um ca. 20 kcal/mol höhere Grundzustandsenergie. —IR-, 1H- und 13C-NMR-Daten von Lösungen von 1 werden diskutiert.
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    Relative Reaktivität Alkyl-substituierter Alkene und Cycloalkene gegenüber Diarylcarbenium-Ionen (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2473-2496 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Relative Reactivities of Alkyl-Substituted Alkenes and Cycloalkenes towards Diarylcarbenium IonsThe relative reactivities of alkyl-substituted alkenes 4 towards diarylmethyl cations 2 generated in situ from diarylmethyl chlorides 1 and Lewis acids were determined by competition experiments. The relative reactivities were almost independent of the nature of the Lewis acid. Eventual differences of the solvation free enthalpies of various activated complexes are, therefore, independent of the nature of the gegen ions. The rate acceleration by methyl groups - 6-50 by CH3 at the attacked vinylic position and approximately 104 at the developing carbenium centre - indicates a scarcely bridged transition state.
    Notes: Nach der Konkurrenzmethode wurden die relativen Reaktivitäten Alkyl-substituierter Alkene 4 gegenüber Diarylmethyl-Kationen 2 bestimmt, die in Gegenwart von Alken-Gemischen aus Diarylmethylchloriden 1 und Lewis-Säuren erzeugt wurden. Die Konkurrenz-konstanten werden durch die Art der Lewis-Säure nur wenig beeinflußt, so daß eine eventuelle Differenz der freien Solvatationsenthalpie verschiedener aktivierter Komplexe von der Natur des Gegenions unabhängig sein muß. Aus der 6-50fachen Reaktionsbeschleunigung durch Methylgruppen, die sich am angegriffenen Alken-Kohlenstoff befinden und der 104fachen Reaktivitätssteigerung durch Methylgruppen am neuen Carbeniumzentrum wird auf einen wenig verbrückten Übergangszustand geschlossen.
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    Synthese von 2,5-Diazido-3,6-dicyan- und 2,6-Diazido-3,5-dicyan-1,4-benzochinon zur Darstellung von Dicyanketen (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 844-849 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses of 2,5-Diazido-3,6-dicyano- and 2,6-Diazido-3,5-dicyano-1,4-benzoquinone for the Preparation of DicyanoketeneTwo short syntheses of 2,5-diazido-3,6-dicyano- (1) and 2,6-diazido-3,5-dicyano-1,4-benzo-quinone (3) as starting materials for the preparation of dicyanoketene in situ are reported; beyond that the compounds 14, 15, and 16a, b are synthesized.
    Notes: Es wird über zwei wenigstufige Synthesen von 2,5-Diazido-3,6-dicyan- (1) und 2,6-Diazido-3,5-dicyan-1,4-benzochinon (3) als Ausgangssubstanzen zur Darstellung von Dicyanketen in situ berichtet; darüber hinaus werden die Verbindungen 14, 15 und 16a, b dargestellt.
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    Ester der Ferrocendithiocarbonsäure (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 850-856 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Esters of Ferrocenedithiocarboxylic AcidTwo methods were used to prepare esters of ferrocenedithiocarboxylic acid: 1. Alkylation of the ferrocenedithiocarboxylate anion in the piperidinium salt [C5H10NH2]+[Fc—CS2]- (1) by CH3I, C2H5I, and ethylene oxide gave mononuclear esters Fc—C(S)SR (R = CH3 (2), C2H5 (3), CH2CH2OH (4)), whereas the dinuclear methylene diester [Fc—C(S)S]2CH2 (9a) was formed using either CH2Cl2 or CH2I2. 2. The reaction of ferrocenecarbonyl chloride, Fc—C(O)Cl, with methanethiol, CH3SH, to give Fc—C(O)SCH3 (7) and subsequent sulfuration by P4S10 furnished Fc—C(S)SCH3 (2). The analogous reactions with dithiols, HS[CH2]nSH (n = 2 - 4), led to the dinuclear compounds [Fc—C(S)S]2[CH2]n (n = 2 (9b), 3 (9c), 4 (9d)). All the intermediates of the composition Fc—C(O)S[CH2]nSH (11b - d), [Fc—C(O)S]2[CH2]n (12b - d), and Fc—C(S)S[CH2]nSC(O) - Fc (13b - d) could be isolated. The new compounds were characterized on the basis of their 1H and 13C NMR spectra.
    Notes: Zwei Methoden wurden zur Darstellung von Estern der Ferrocendithiocarbonsäure angewandt: 1. Die Alkylierung des Ferrocendithiocarboxylat-Anions im Piperidinium-Salz [C5H10NH2]+ [Fc—CS2]- (1) mit CH3I, C2H5I und Ethylenoxid ergab einkernige Ester, Fc—C(S)SR (R = CH3 (2), C2H5 (3), CH2CH2OH (4)), während mit CH2Cl2 oder CH2I2 der zweikernige Methylendiester [Fc—C(S)S]2CH2 (9a) entstand. 2. Die Umsetzung von Ferrocencarbonsäurechlorid, Fc—C(O)Cl, mit Methanthiol, CH3SH, zu Fc—C(O)SCH3 (7) und anschließende Sulfurierung mit P4S10 lieferte Fc—C(S)SCH3 (2). Die analoge Reaktion mit Dithiolen HS[CH2]nSH (n = 2 - 4) führte zu den Zweikernverbindungen [Fc—C(S)S]2[CH2]n (n = 2 (9b), 3 (9c), 4 (9d)); alle Zwischenstufen der Zusammensetzung Fc—C(O)S[CH2]nSH (11b - d), [Fc—C(O)S]2[CH2]n (12b - d) und Fc—C(S)S-[CH2]nSC(O) - Fc (13b - d) konnten isoliert werden. Die neuen Verbindungen wurden anhand der 1H- und 13C-NMR-Spektren charakterisiert.
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    Synthese und Eigenschaften von substituierten 1-Alkoxy-2-azaallenium-Salzen (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 857-871 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Properties of Substituted 1-Alkoxy-2-azaallenium Salts12 novel substituted 1-alkoxy-2-azaallenium salts 1 have been prepared by reaction of the N-methyleneamides 3 with trialkyloxonium salts 4. During the alkylation reaction of the N-benzylideneamides 3m, n a formal disproportionation takes place to yield higher and lower oxidized 2-azaallenium salts (13, 14 from 3n) as the major products. The salts 1n, r, which are therefore not easily accessible by the alkylation route, can be prepared successfully by an acylation cleavage reaction of the N-(alkoxymethyl)imidates 8. The protonation of the substances 3 takes place exclusively at the nitrogen atom to give the N-acyliminium salts 19. Detailed spectroscopic data (IR, 1H, 13C NMR, MS) are included.
    Notes: Durch Umsetzung der N-Methylencarbonsäureamide 3 mit den Trialkyloxonium-Salzen 4 wurden 12 bislang nicht beschriebene substituierte 1-Alkoxy-2-azaallenium-Salze 1 hergestellt. Bei der Alkylierung der N-Benzylidencarbonsäureamide 3m, n tritt eine formale Disproportionierung zu höher und niedriger oxidierten 2-Azaallenium-Salzen (13, 14 bei 3n) als Hauptreaktion ein, deren Mechanismus untersucht wurde. Die durch Alkylierung nur schlecht zugänglichen Salze 1n, r können besser durch eine Acylspaltung von N-(Alkoxy-methyl)imidsäureestern 8 hergestellt werden. Die Protonierung der Verbindungen 3 erfolgt am Stickstoffatom unter Bildung der N-Acyliminium-Salze 19. Ausführliche spektroskopische Daten (IR, 1H- und 13C-NMR, MS) werden mitgeteilt.
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    Sieben- (N2O2Si3) und achtgliedrige (N2O2Si4) Ringe aus einem (Hydroxysilyl)hydrazin und 1-Amino-3-fluorsiloxanen (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 872-877 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Seven- (N2O2Si3) and Eight-membered (N2O2Si4) Rings from a (Hydroxysilyl)hydrazine and 1-Amino-3-fluorosiloxanesHalogeno-functional siloxanes [(Me3C)2SiCl—O—SiHalR2, Hal = F, R = CMe3 (2), Hal = Cl, R = Ph (3)] are obtained in the reaction of dihalogenosilanes with (Me3C)2Si(Cl)OLi (1a). (Me3C)2Si(Cl)OH reacts smoothly with ammonia to form the aminosilanol (Me3C)2Si(NH2)OH (4). With fluorosilanes its lithium salt 4a yields the amino- and fluoro-functional siloxanes 5 - 8 [(Me3C)2Si(NH2) —O—SiFRR′, R = R′ = Me (5), R = R′ = CMe3 (6), R = F, R′ = CMe3 (7), R = F, R′ = N(SiMe3)2 (8)]. Primary amines react with 1 by intermolecular HCl elimination to give the 1-chloro-3-hydroxysiloxane 9, hydrazine reacts to form the N,N′-bis(hydroxysilyl)hydrazine 10, methylhydrazine to yield the N-(hydroxysilyl)-N-methylhydrazine 11, and N,N′-dimethylhydrazine to give 9. The reaction of the dilithium salt 10a with F3SiN(SiMe3)2 leads to the formation of the seven-membered N2O2Si3 ring 12. The 1,5,3,7,2,4,6,8-dioxadiazatetrasilocanes 13 and 14 are obtained by LiF elimination from lithiated 5 and 7, respectively.
    Notes: Halogenfunktionelle Siloxane [(Me3C)2SiCl - O—SiHalR2, Hal = F, R = CMe3 (2), Hal = Cl, R = Ph (3)] werden durch Reaktion der Dihalogensilane mit (Me3C)2Si(Cl)OLi (1a) erhalten. Mit Ammoniak reagiert (Me3C)2Si(Cl)OH (1) glatt unter Bildung des Aminosilanols (Me3C)2Si(NH2)OH (4), dessen Lithiumsalz 4a mit Fluorsilanen die amino- und fluorfunktionellen Siloxane 5 - 8 [(Me3C)2Si(NH2) - O—SiFRR′, R = R′ = Me (5), R = R′ = CMe3 (6), R = F, R′ = CMe3 (7), R = F, R′ = N(SiMe3)2 (8)] bildet. Primäre Amine reagieren mit 1 unter intermolekularer HCl-Abspaltung zum 1-Chlor-3-hydroxysiloxan 9, Hydrazin zum N,N′-Bis(hydroxysilyl)hydrazin 10, Methylhydrazin zum N-(Hydroxysilyl)-N′-methyl-hydrazin 11 und N,N′-Dimethylhydrazin zu 9. Die Reaktion des Dilithiumsalzes 10a mit F3SiN(SiMe3)2 führt zur Bildung des siebengliedrigen N2O2Si3-Ringes 12. Durch LiF-Eliminierung aus lithiiertem 5 und 7 entstehen die 1,5,3,7,2,4,6,8-Dioxadiazatetrasilocane 13 und 14.
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    Chemie der Übergangsmetall-Heterocyclen-Komplexe, II. Synthese und Elektrochemie von Carbonylchrom-Komplexen der Bithiophen-Reihe (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 878-886 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Chemistry of Transition Metal Heterocyclic Complexes, II. Synthesis and Electrochemistry of Carbonyl Chromium Complexes in the Bithiophen SeriesThe (substituted) (bithiophene)tricarbonylchromium complexes 4a - g are formed in yields up to 95% upon treatment of tricarbonyltris(γ-picoline)chromium with 2,2′-bithiophene (1a) and its derivatives 1b - e and 1g, respectively, in the presence of the Lewis acid BF3. The oxidation of the new compounds, as investigated by means of cyclovoltammetry, is irreversible and effects decomposition of the complexes.
    Notes: Durch Umsetzung von Tricarbonyltris(γ-picolin)chrom (3) mit 2,2′-Bithiophen (1a) und seinen Derivaten 1b - e und 1g bilden sich in Gegenwart der Lewis-Säure BF3 die (substituierten) Bithiophen-Chromtricarbonyl-Komplexe 4a - g in Ausbeuten bis 95%. Die cyclovoltametrisch untersuchte Oxidation der neuen Verbindungen verläuft irreversibel unter Zerfall der Komplexe.
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    Oxidative aminomercuration of 2-propyn-1-ols. Stereoselective syntheses and structures of cis-[1,4]oxazino[3,2-b]-1,4-oxazine derivatives (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 887-899 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Oxidative Aminomercurierung von 2-Propin-1-olen. Stereoselektive Synthese und Struktur von cis-[1,4]Oxazino[3,2-b]-1,4-oxazin-DerivatenDie Reaktion von 2-Propin-1-olen 1 mit 2-Aminoalkoholen 7 in Gegenwart von Quecksilber(II)-chlorid beginnt mit einer oxidativen Aminomercurierung, gefolgt von hoch stereo-selektiven Reaktionsschritten, die zu cis-[1,4]Oxazino[3,2-b]-1,4-oxazin-Derivaten 10 führen. Nach den Röntgenstrukturanalysen von 10c,f,g zeigen diese Verbindungen die gleiche Anordnung um die zentrale Bindung, und zwar so, daß die anomere Stabilisierung ein Maximum erreicht.
    Notes: The reactions of 2-Propin-1-ols 1 with 2-amino alcohols 7 and mercury(II) chloride start with an oxidative aminomercuration step followed by a series of highly stereoselective processes leading to cis-[1,4]oxazino[3,2-b]-1,4-oxazine derivatives 10. X-Ray analyses of 10c,f,g show that these compounds have the same geometrical arrangement around their central fusion bond in such a way that anomeric stabilisation reaches a maximum.
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    Decabenzylgermanocen, -stannocen und -plumbocen. Synthese und Struktur von luftstabilen Metallocenen der 4. Hauptgruppe des Periodensystems der Elemente (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2656-2667 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Decabenzylgermanocene, -stannocene and -plumbocene. Synthesis and Structure of Air-stable Metallocenes of Main Group IVGermanium diiodide, tin dichloride, or lead diacetate reacts with pentabenzylcyclopentadienyllithium (1) to give decabenzylgermanocene (2), decabenzylstannocene (3) or decabenzylplumbocene (4), respectively. The air-stable metallocenes were characterized by IR, Raman, NMR, tin-119m-Mössbauer (3), and mass spectroscopy. The X-ray structural analysis shows for all three compounds an angle of 31 to 36° between the planes of the two cyclopentadienyl rings and a shielding of the lone pair of electrons at the metal atom by three of the ten benzyl groups each.
    Notes: Germaniumdiiodid, Zinndichlorid bzw. Bleidiacetat reagiert mit Pentabenzylcyclopentadienyllithium (1) unter Bildung von Decabenzylgermanocen (2), Decabenzylstannocen (3) bzw. Decabenzylplumbocen (4). Die luftstabilen Metallocene wurden durch IR-, Raman-, NMR-, 119mSn-Mößbauer- (3) und Massenspektren charakterisiert. Die Röntgenstrukturanalyse der Verbindungen zeigt, daß die Ebenen der beiden Cyclopentadienylringe einen Winkel zwischen 31 und 36° einschließen, und daß eine Abschirmung des freien Elektronenpaares am Metallatom jeweils durch drei der zehn Benzylgruppen erfolgt.
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    URL: http://dx.doi.org/10.1002/cber.19861190822
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    Asymmetrische reduktive Aminierung von Cycloalkanonen, 5. Synthese und absolute Konfiguration 2-substituierter Cyclopentanamine (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2668-2677 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Asymmetric Reductive Amination of Cycloalkanones, 5. Synthesis and Absolute Configuration of 2-Substituted CyclopentanaminesIn an asymmetric synthesis 2-substituted cyclopentanamines are obtained from racemic cyclopentanones by means of reductive amination in a three-step procedure. Condensation of the ketones 3(n) with optically active 1-phenylethylamines yields imine mixtures 4(n), which are hydrogenated with Raney nickel to give the optically active, diastereomerically pure secondary amines 5(n). Hydrogenolysis with Palladium-on-charcoal leads to high grade enantiomerically pure primary amines 6(n) with good yields. The relative configuration of the amines 5(n) and 6(n) is elucidated by 1H and 13C NMR techniques. The absolute configuration is determined by X-ray analysis of the 4-bromobenzamide 8 of the primary amine (+)-6(n)e and with the help of CD of the salicylidenes 9(n). The kinetically controlled asymmetric hydrogenation with a first order transformation as proved reaction mechanism in the cyclohexanamine line is confirmed for this investigation. The hydrogenation runs like-induced to the cis-configurated amines 5(n) and 6(n), respectively.
    Additional Material: 5 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19861190823
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    Electron transfer reactions. Reaction of furanones and bifurandiones with potassium and oxygen (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 917-928 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Elektronen-Übertragungs-Reaktionen. Reaktion von Furanonen und Bifurandionen mit Kalium und SauerstoffBei der Behandlung von Furanonen (1a - c, 25, 34) und Bifurandionen (23, 37) mit Kalium in THF entstehen Radikalanion-Zwischenstufen, die mit Sauerstoff zu Superoxid reagieren, das seinerseits mit den Ausgangsfuranonen und -bifuranonen weiterreagiert. So ergab die Reaktion von 1a mit Kalium eine Mischung von 4-Oxo-2,2,4-triphenylbutansäure (7a), 1,3,3-Triphenyl-2-propen-1-on (11a) und Benzoesäure (12). Unter ähnlichen Bedingungen reagierte 11a selbst zu einer Mischung von Benzophenon (18a) und 12. Ähnliche Ergebnisse wurden im Falle von 1b und c erhalten. Das Bifurandion 23 ergab mit Kalium eine Mischung von 2(5H)-Furanon 25, 2,3-Diphenylpropensäure (31) und 12. 25 selbst reagierte mit Kalium unter ähnlichen Bedingungen zur selben Mischung von 31 und 12. 3-Phenyl-2(3H)-benzofuranon (34) führte mit Kalium jedoch zu keinem isolierbaren Produkt; nur Ausgangsmaterial wurde zurückgewonnen. Unter vergleichbaren Bedingungen lieferte das Bifurandion 37 das Fragmentierungsprodukt 34. Mit Hilfe der cyclischen Voltammetrie wurden die zu den Radikalanionen führenden Reduktionspotentiale gemessen. Die Radikalanion-Zwischenstufen wurden durch ihre Elektronenspektren charakterisiert.
    Notes: Treatment of furanones (1a - c, 25, 34) and bifurandiones (23, 37) with potassium in THF gave rise to radical anion intermediates, which reacted with oxygen to give superoxide and ultimately products derived through the reaction of superoxide with the starting furanones and bifurandiones. Thus, the reaction of 1a with potassium gave a mixture of 4-oxo-2,2,4-triphenylbutanoic acid (7a), 1,3,3-triphenyl-2-propen-1-one (11a), and benzoic acid (12). The reaction of 11a itself, under similar conditions, gave a mixture of benzophenone (18a) and 12. Similar reactions have been observed in the case of 1b and c. The bifurandione 23, on treatment with potassium, gave a mixture of the 2(5H)-furanone 25, 2,3-diphenylpropenoic acid (31), and 12. The reaction of 25 itself with potassium under similar conditions gave the same mixture of 31 and 12. Treatment of 3-phenyl-2(3H)-benzofuranone (34) with potassium, however, did not give any isolable product; only the starting material could be recovered. Under similar conditions, the bifurandione 37 gave the fragmentation product 34. Cyclic voltammetric studies have been employed to measure the reduction potentials, leading to radical anions, and these intermediates have been characterized through their electronic spectra.
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    Reactions of uracils, 7. Synthesis and novel consecutive thermal [1,5]-sigmatropic rearrangements of 6-(alkylamino)-5-ethenyluracils (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 943-949 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reaktionen von Uracilen, 7. Synthese und eine neue Sequenz thermischer [1,5]-sigmatroper Umlagerungen von 6-(Alkylamino)-5-ethenyluracilenNeue 6-(Alkylamino)-5-ethenyluracile (2d und 7) werden dargestellt, um Substituenteneffekte bei thermischen Reaktionen zu untersuchen. Ähnlich 2a werden 2d und 7 beim Erhitzen in Dowtherm® A und nach anschließender Verseifung in die 6-Amino-5-(ethoxycarbonyl[phenyl]ethyl)uracile 4 bzw. 8 übergeführt. Erhitzen in Xylol liefert die intermediären Imine 11 und 12. Deuterierungsexperimente belegen aufeinanderfolgende thermische [1,5]-H-Wanderungen (2a-D1 → 4-D1 und 4-D2; 2a′-D2 → 4′-D1). Die Mechanismen werden diskutiert.
    Notes: Additional 6-(alkylamino)-5-ethenyluracils (2d, 7) have been prepared for investigating substituent effects in thermal reactions. Like 2a, upon heating in Dowtherm® A 2d and 7 afford after saponification 6-amino-5-(ethoxycarbonyl[phenyl]ethyl)uracils 4 and 8, respectively. After refluxing in xylene the intermediary imines 11 and 12 can be isolated. Deuteration experiments reveal consecutive thermal [1,5]H-migrations (2a - D1 → 4-D1, and 4-D2; 2a′-D2 → 4′-D1). The mechanism is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19861190317
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    1-Methylbenzvalen - Synthese und einige Reaktionen (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 960-970 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 1-Methylbenzvalene - Synthesis and Several Reactions1-Methylbenzvalene (1) has been obtained in preparatively useful quantities from the reaction of cyclopentadienyllithium with 1,1-dichloroethane and n-butyllithium. Hydrogenation of 1 by means of diimine afforded 1-methyltricyclo[3.1.0.02,6]hexane (3). Addition of benzonitrile oxide and 2,4,6-trimethylbenzonitrile oxide to the double bond of 1 gave rise to the formation of a mixture of the isomeric Δ2-isoxazoline derivatives 4 and 5. 4-Methyl-4H-1,2,4-triazole-3,5-dione and 1 reacted to give the rearranged adducts 6 - 8. At temperatures as low as 20°C 8 transformed slowly into the dihydrodiazasemibullvalene derivative 9. Using [6-D]-1-methylbenzvalene (1a) the mechanisms of the reactions leading to 6 - 9 have been studied.
    Notes: Aus der Reaktion von Cyclopentadienyllithium mit 1,1-Dichlorethan und n-Butyllithium ging in präparativ brauchbaren Mengen 1-Methylbenzvalen (1) hervor. Seine Hydrierung mit Diimin erbrachte 1-Methyltricyclo[3.1.0.02,6]hexan (3). Benzonitriloxid und 2,4,6-Trimethylbenzonitriloxid addierten sich an die Doppelbindung von 1 unter Bildung von Gemischen der isomeren Δ2-Isoxazolin-Derivate 4 und 5. 4-Methyl-4H-1,2,4-triazol-3,5-dion ergab mit 1 die umgelagerten Addukte 6 - 8. Schon bei 20°C wandelte sich 8 langsam in das Dihydrodiazasemibullvalen-Derivat 9 um. Durch Einsatz von [6-D]-1-Methylbenzvalen (1a) wurden die Mechanismen der zu 6 - 9 führenden Reaktionen untersucht.
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    Additionen von Benzvalen an Nitriloxide. Eine Synthese für Benzvalen-3-carbonitril (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 950-959 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Additions of Benzvalene to Nitrile Oxides. A Synthesis for Benzvalene-3-carbonitrile2,4,6-Trimethylbenzonitrile oxide, benzonitrile oxide, and fulminic acid undergo cycloaddition to benzvalene (1) to give the Δ2-isoxazolines 2a - c in high yields. By means of competition experiments the ratio of the rate constants for the reactions of 1 and norbornene with benzonitrile oxide has been determined to be kbenzvalene/knorbornene ≈ 1. The adduct 2c of fulminic acid was transformed to benzvalene-3-carbonitrile (4) by the following simple sequence: ring opening by sodium methoxide to yield the β-hydroxycarbonitrile 3, tosylation of 3, and, finally, elimination of toluenesulfonic acid with potassium tert-butoxide. - From the X-ray structure analysis of 2b the dihedral angle and the length of the central bond of the bicyclo[1.1.0]butane moiety have been determined to be 111.8° and 1.464 Å, respectively.
    Notes: 2,4,6-Trimethylbenzonitriloxid, Benzonitriloxid und Knallsäure ergaben mit Benzvalen (1) in hohen Ausbeuten die Δ2-Isoxazoline 2a - c. Durch Konkurrenzexperimente wurde das Verhältnis der Geschwindigkeitskonstanten der Additionen von Benzonitriloxid an 1 und Norbornen kBenzvalen/kNorbornen ≈ 1 bestimmt. Das Knallsäure-Addukt 2c ließ sich in der folgenden einfachen Reaktionssequenz in Benzvalen-3-carbonitril (4) umwandeln: Ringöffnung durch Natrium-methoxid zum β-Hydroxynitril 3, dessen Tosylierung und schließlich Eliminierung von Toluol-sulfonsäure mit Kalium-tert-butoxid. - Mit Hilfe der Röntgenstrukturanalyse wurden für das Bicyclo[1.1.0]butan-Gerüst von 2b der Interplanarwinkel zu 111.8° und die Länge der Zentral-bindung zu 1.464 Å ermittelt.
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    URL: http://dx.doi.org/10.1002/cber.19861190318
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    Reaktive π-Übergangsmetallkomplexe der 8. Nebengruppe, I. (η6-Aren)(η5-2,5-dihydro-1,2,5-thiadiborol)eisen: Synthesen aus Bis(aren)eisen und Aren-bis(ethen)eisen (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 971-979 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactive π-Complexes of the Group VIII Transition Metals, I. (η6-Arene)(η5-2,5-dihydro-1,2,5-thiadiborol)iron: Syntheses from Bis(arene)iron and Arene-bis(ethene)ironBis(arene)iron 1a - e, (arene = p-xylene, benzene, benzotrifluoride, 1,4-difluorobenzene) react in the temperature range of -100 to -60°C with 3,4-diethyl-2,5-dihydro-2,5-dimethyl-1,2,5-thiadiborole (thiadiborolene, 2) to form reactive intermediates which decompose at -30°C and (η6-arene)(η5-thiadiborolene)iron 3a - e are obtained. Alternatively, the synthesis is achieved via arene-bis(ethene)iron 4a,c (arene = p-xylene, benzene), which is formed from 1a,c and ethene at low temperature. Reactions, spectroscopic data, and the crystal structure of (η6-benzene)(η5-thiadiborolene)iron (3c) are reported.
    Notes: Bis(aren)eisen 1a - e (Aren = p-Xylol, Toluol, Benzol, Benzotrifluorid, 1,4-Difluorbenzol) reagieren im Temperaturbereich von - 100 bis -60°C mit 3,4-Diethyl-2,5-dihydro-2,5-di-methyl-1,2,5-thiadiborol (Thiadiborolen, 2) zu reaktiven Zwischenverbindungen, die durch Zersetzung bei -30°C (η6-Aren)(η5-thiadiborolen)eisen 3a - e ergeben. Alternativ gelingt die Synthese über Aren-bis(ethen)eisen 4a, c (Aren = p-Xylol, Benzol), welche bei tiefen Temperaturen aus 1a, c und Ethen darstellbar sind. Reaktionen, spektroskopische Daten und die Kristallstruktur von (η6-Benzol)(η5-thiadiborolen)eisen (3c) werden mitgeteilt.
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    URL: http://dx.doi.org/10.1002/cber.19861190320
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    Darstellung, ESR- und ENDOR-Untersuchung von Radikalkationen des Tetraphenylhydrazins, des 5,6-Dihydro-5,6-diphenylbenzo[c]cinnolins und des Benzo[c]benzo[3,4]cinnolino[1,2-a]cinnolins (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 980-990 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Generation, ESR and ENDOR Study of Radical Cations Derived from Tetraphenylhydrazine, 5,6-Dihydro-5,6-diphenylbenzo[c]cinnoline, and Benzo[c]benzo[3,4]cinnolino[1,2-a]cinnolineRadical cations of the title compounds (1a·+, 2·+, 3·+) and of a series of derivatives (1b·+, 1ċ+, 6a·+ - ċ+) representing hydrazine radical cations were generated by oxidation. ENDOR studies of the tetraarylhydrazine radical cations 1a·+ - ċ+ confirm the hindered rotation of the aryl groups and yield a partial assignment of the hyperfine splitting constants. According to the ESR-ENDOR results of 1a·+ and 3·+ linkage of the N,N′-phenyl groups through their o-positions does not considerably flatten the conjugation system.
    Notes: Die Hydrazin-Radikalkationen der Titelverbindungen (1a·+, 2·+, 3·+) sowie einer Reihe von Derivaten (1b·+, 1c·+, 6a·+ - e·+) wurden durch Oxidation erzeugt. ENDOR-Untersuchungen der Tetraarylhydrazin-Radikalkationen 1a·+ - c·+ bestätigen die gehinderte Rotation der Arylreste und liefern eine partielle Zuordnung der HFS-Kopplungskonstanten. Nach den ESR- und ENDOR-Ergebnissen von 1a·+ und 3·+ führt die Verknüpfung der N,N′-Phenylreste über ihre o-Positionen zu keiner beträchtlichen Einebnung des Konjugationssystems.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19861190321
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    Über die Konfigurations- und Substituenten-Abhängigkeit der Pt — Cl-Valenzschwingungsfrequenzen und der 31P-NMR-Parameter in substituierten cis- und trans-Dichlorobis-(triphenylphosphan)platin(II)-Verbindungen (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 1694-1703 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Configurational and Substituent Dependence of the Pt—Cl Stretching Frequencies and of the 31P NMR Parameters in Substituted cis- and trans- Dichlorobis(triphenylphosphane)platinum(II) CompoundsCorrelations between substituent constants σ, Pt — Cl vibrational frequencies and 31P NMR parameters 1J[195Pt,31P] und δ[31P] for compounds of the type cis- and trans-{Pt-[P(aryl)(aryl′)(aryl″)]2 Cl2} (aryl, aryl′, aryl″ = substituted phenyl rings) are reported and discussed with respect to bonding properties.
    Notes: Zusammenhänge zwischen Substituenten-Konstanten σ, Pt—Cl-Valenzschwingungsfrequenzen und 31P-NMR-Parameter 1J[195Pt, 31P] und δ[31P] für die Verbindungen des Typs cis- und trans-{Pt[P(aryl)(aryl′)(aryl″)]2 Cl2} (aryl, aryl′, aryl″ = substituierte Phenyl-Ringe) werden beschrieben und im Hinblick auf die Bindungseigenschaften diskutiert.
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    URL: http://dx.doi.org/10.1002/cber.19861190521
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    Photochemie des 1,3-Distyrylbenzols  -  Ein neuer Weg zu syn-[2.2](1,3)Cyclophanen (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 1704-1715 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Photochemistry of 1,3-Distyrylbenzene  -  A New Route to syn-[2.2](1,3)CyclophanesDepending on the reaction conditions the irradiation of the title compound 1 leads to cyclodimerization 1 → 6, dehydrogenating cyclization 1 → 11, 12 or a combination of both processes 1 → 13, 14, 15. The stereoisomeric [2.2](1,3)cyclophanes 6a - c as well as the access into the pyrene series 15, 16, 18 are of special synthetic interest.
    Notes: In Abhängigkeit von den Reaktionsbedingungen beobachtet man bei der Photolyse der Titelverbindung 1 Cyclodimerisierung 1 → 6, dehydrierende Cyclisierung 1 → 11, 12 oder eine Kombination von beiden 1 → 13, 14, 15. Von besonderem synthetischem Interesse sind dabei die stereoisomeren [2.2](1,3)Cyclophane 6a - c und der Zugang in die Pyrenreihe 15, 16, 18.
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    URL: http://dx.doi.org/10.1002/cber.19861190522
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    Reaction of trialkyl orthoformates with the aluminium derivatives of some α-unsaturated bromides. Preparation of β-unsaturated acetals (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 1725-1730 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reaktion von Trialkylorthoformaten mit den Aluminium-Derivaten einiger α-ungesättigter Bromide. Darstellung von β-ungesättigten AcetalenDie Aluminium-Derivate 2, 4 und 7 α-ungesättigter Bromide, dargestellt in Ether, sind sehr reaktionsfähig gegenüber Trialkylorthoformaten. Mit Hilfe dieser Reaktion, durchgeführt bei -80°C, können auf einfache Weise β-ungesättigte Acetale 3, 5 bzw. 8 dargestellt werden.
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    URL: http://dx.doi.org/10.1002/cber.19861190524
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    Fluoreszenz-Untersuchungen an styrylsubstituierten Benzolen (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 1716-1724 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Investigations on the Fluorescence of Styryl-substituted BenzenesFluorescence decay measurements of the stilbene-like compounds 1 - 4 demonstrate that the average lifetimes of these molecules in the electronically excited singlet state are about 102 times higher than for trans-stilbene itself. According to UV absorption and excitation spectra this is due to a new S1 state, which corresponds to a forbidden S0 → S1 transition on the long-wavelength edge of the intense absorption.
    Notes: Die Fluoreszenz-Abklingzeiten der stilbenartigen Verbindungen 1 - 4 zeigen, daß die mittleren Lebensdauern dieser Moleküle im elektronisch angeregten Singulettzustand um rund zwei Zehnerpotenzen höher sind als bei trans-Stilben selbst. Anhand von UV-Absorptions-und Anregungsspektren wird das auf einen neu gefundenen S1-Zustand zurückgeführt, der einem verbotenen Übergang S0 → S1 auf der langwelligen Seite der intensiven Absorption entspricht.
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    URL: http://dx.doi.org/10.1002/cber.19861190523
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    Enantioselektive katalytische Hydrierung von α-(Acetylamino)-zimtsäure mit einem Rhodium-Phosphankomplex in wäßriger Lösung (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 1731-1733 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Enantioselective Catalytic Hydrogenation of α-(Acetylamino)cinnamic Acid with a Rhodium Phosphane Complex in Aqueous SolutionThe synthesis of [(3R,4R)-3,4-bis(diphenylphosphino)-1,1-dimethylpyrrolidinium-P,P′](1,5-cyclooctadiene)rhodium bis(tetrafluoroborate) (5) is described. With this water-soluble catalyst the sodium salt 6c of α-(Acetylamino)cinnamic acid (6a) is hydrogenated in aqueous solution to give (S)-N-acetylphenylalanine with 90% ee.
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    McMurry-Reaktion der 2-Alkyl-3-ethoxyacroleine (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 1734-1736 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: McMurry Reaction of 2-Alkyl-3-ethoxyacroleinsMcMurry reductive coupling of 2-alkyl-3-ethoxyacroleins 1 yields 2,5-dialkylhexadienedials 6. (E) Configuration at the 2,3- and 4,5-double bonds of these dialdehydes is derived from three-bond carbon-13 proton coupling. A mechanism similiar to that discussed for McMurry coupling of carbonyl compounds is proposed.
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    Masthead (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986) 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19861190601
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    Oxopropenylierung von Alkylmagnesiumhalogeniden mit 3-(Trimethylsilyloxy)acroleinen (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 1737-1744 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Oxopropenylation of Alkylmagnesium Halides by 3-(Trimethylsilyloxy)acroleinsOxopropenylation of alkylmagnesium halides 4 by 3-(trimethylsilyloxy)acroleins 3 selectively yields the (E)-isomers of α,β-unsaturated aldehydes such as 4-phenyl-2-butenals 9, 3-cyclopropylpropenals 10, 3-cyclohexylpropenals 11, 3-(3-menthyl)propenals 12, and 2,5-hexadienals 13. 3-Hydroxyenolsilylethers 6 are isolated when allylmagnesium chloride is used as carbon nucleophile; to conclude, the reaction primarily involves nucleophilic addition of the Grignard reagent at the aldehyde carbon of the acrolein 3.
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    URL: http://dx.doi.org/10.1002/cber.19861190527
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  • 88
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    Metallkomplexe mit verbrückten permethylierten Cyclopentadienylliganden (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 1750-1754 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Metal Complexes with Bridged Permethylated Cyclopentadienyl LigandsThe preparation of the permethylated silyl-bridged dicyclopentadienyl ligands Me2Si(Me4C5H)2 (1) and C2H4(Me2Si(Me4C5H))2 (2) is reported. Reaction of dimetalated 1 with TiCl4 and ZrCl4 yielded the corresponding metallocenophane dihalides 3 and 4, while treatment of the dilithio derivative of 2 with GeCl2 · dioxane, SnCl2, and FeCl2 yielded the bridged metallocenes 5, 6, and 7.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19861190529
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    Synthese neuer 1λ6,2,6-Thiadiazine durch Kondensationsreaktion mit S,S-Dialkylschwefeldiimiden (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 1745-1749 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis of New 1λ6,2,6-Thiadiazines by Condensation with S,S-Dialkylsulfur DiimidesReactions of ketene mercaptals 1a, b, d with S,S-dialkylsulfur diimides 2a - c lead to colourless 1λ6,2,6-thiadiazines 4a - i; reaction of 1c with 2a - c leads to ring-open products 3a - c. 5-Methyl-substituted 1λ6,2,6-thiadiazines 6a, c, d can be prepared by condensation of S,S-dialkylsulfur diimides 2a, c, d with acrylic acid derivative 5.
    Additional Material: 2 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19861190528
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    Diazoverbindungen, 68. Dibenzo[a,c]cyclooctene und Dibenzo[a,c]heptafulvene aus 5-(Diazomethyl)-5H-dibenzo[a,c]cycloheptenen (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 1755-1765 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Diazo Compounds, 68. Dibenzo[a,c]cyclooctenes and Dibenzo[a,c]heptafulvenes from 5-(Diazomethyl)-5H-dibenzo[a,c]cycloheptenes5,6-Dichloro-5H-dibenzo[a,c]cycloheptene (11) reacts with the silver (diazomethyl)phosphoryl compounds 12a-d and the mercury bis(diazomethylcarbonyl) compounds 12e-h, respectively, by electrophilic diazoalkane substitution to yield the 5-(diazomethyl)-5H-dibenzo[a,c]cycloheptenes 14a-h. The copper(II) acetylacetonate-catalyzed decomposition of 14a, c, e and g in toluene leads to the formation of both dibenzo[a,c]cyclooctenes 16a-d and 17a, b by ring enlargement and of dibenzo[a,c]heptafulvenes 18a-d by 1,2-H-shift.
    Notes: 5,6-Dichlor-5H-dibenzo[a,c]cyclohepten (11) geht mit den Silber-(diazomethyl)phosphorylverbindungen 12a-d bzw. den Quecksilber-bis(diazomethylcarbonyl)verbindungen 12e-h elektrophile Diazoalkansubstitution zu den 5-(Diazomethyl)-5H-dibenzo[a,c]cycloheptenen 14a-h ein. Kupfer(II)-acetylacetonat-katalysierte Zersetzung von 14a,c,e und g in Toluol führt über Ringerweiterung zu den Dibenzo[a,c]cyclooctenen 16a-d und 17a,b sowie unter 1,2-H-Shift zu den Dibenzo[a,c]heptafulvenen 18a-d.
    Additional Material: 5 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19861190602
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    Trimethylsilylcyanid als Umpolungsreagens, XI. Über den ambidenten Charakter substituierter Allyl-Anionen (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 1772-1800 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Trimethylsilyl Cyanide  -  A Reagent for Umpolung, XI. On the Ambident Character of Substituted Allylic AnionsThe dependence of the α/γ-ratio of alkylation products on several factors has been determined with 1-cyano-3-aryl-1-(trimethylsiloxy)allylic anions. Increasing amounts of γ-product are found in more polar solvents, with larger alkali ions, on addition of HMPT, with smaller alkyl groups in the electrophile, and especially with p-cyanophenyl groups. In contrast, temperature and leaving groups have minor effects. On substitution of the O-silyl group by O-methyl and O-ethoxycarbonyl, α-alkylation predominates strongly. The results are compared to known allylic anions. Furthermore, the isomerisation of compounds of type C to type B is described as well as a new addition reaction of cyanoformates to aldehydes.
    Notes: An 1-Cyan-3-aryl-1-(trimethylsiloxy)allyl-Anionen (6) wird das Verhältnis der α/γ-Alkylierung in Abhängigkeit von verschiedenen Faktoren bestimmt. Dabei wird der γ-Anteil durch stärker polare Solventien, größere Alkali-Ionen, Zusatz von HMPT, kleinere Alkylreste im Elektrophil und besonders p-Cyanphenylreste erhöht, während Abgangsgruppen des Elektrophils und die Temperatur wenig Einfluß ausüben. Ersatz der O-Silylgruppe durch die O-Methyl- und O-Ethoxycarbonylgruppe bewirkt α-Alkylierung. Die Ergebnisse werden im Vergleich mit literaturbekannten Allyl-Anionen diskutiert. Außerdem werden die Isomerisierung der Verbindungen vom Typ C zu Typ B sowie eine neue Additionsreaktion von Cyanameisensäureester an Aldehyde beschrieben.
    Additional Material: 13 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19861190604
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    Norpinene (Bicyclo[3.1.1]hept-2-ene) aus Homobenzvalenen (Tricyclo[4.1.0.02,7]hept-3-enen) (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 3027-3044 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Norpinenes (Bicyclo[3.1.1]hept-2-enes) from Homobenzvalenes (Tricyclo[4.1.0.02,7]hept-3-enes)4,5-Dibromo-(1b) and 4,5-dichlorohomobenzvalene (1c) were converted into the tetrahalonorpinenes 2b, c by elemental bromine. In the case of unsubstituted homobenzvalene (1a) the analogous reaction could be achieved in 1% yield only by pyridinium perbromide. Treatment of 1a, b as well as of chlorohomobenzvalenyl nitrobenzoate 1d with iodine furnished the diiodonorpinenes 3a-c. However, 7,7-dibromotetracyclo[4.1.0.02,4.03,5]heptane (4) and bromine gave the tetrabromo-trans-tricyclo[4.1.0.02,4]heptane derivative 5. - On irradiation in the presence of thiophenol, the homobenzvalenes 1a, c, e, f were transformed into the 6-(phenylthio)norpinenes 6a-d. The hydroxyhomobenzvalenes 1g, h afforded the 6-(phenylthio)norpinenes 6e, g as major products, the configuration at C-4 of which is inverted as compared to that of 6b-d. By using [D2]-1a it was shown that with respect to stereochemistry the addition of thiophenol does not proceed uniformly. Without irradiation, 1a was consumed by thiophenol rather slowly at 20°C with formation of the norcarene derivatives 9 and 10 in addition to 6a. - By treatment with LiAlH4 the dichloro compound 6b gave the monochloro derivative 6h. Both 6b and 6h, however the latter one with a better yield, were converted into unsubstituted norpinene (11a) by means of sodium in liquid ammonia, thus providing a new and preparatively useful synthesis for 11a. Analogously, 6c, d furnished 4-phenylnorpinene (11b). The reaction of norpinenes 3a and 11a with N-bromosuccinimide produced the allylbromides 3d and 11c, respectively. - The 13C NMR spectra of the 4-substituted norpinenes revealed a diagnostically important γ-anti-substituent effect.
    Notes: 4,5-Dibrom-(1b) und -Dichlorhomobenzvalen (1c) wurden durch elementares Brom in die Tetrahalogennorpinene 2b, c umgewandelt. Die analoge Reaktion konnte bei unsubstituiertem Homobenzvalen (1a) mit 1% Ausbeute nur durch Pyridiniumperbromid erzielt werden. Aus 1a, b sowie dem Chlorhomobenzvalenyl-nitrobenzoat 1d und Iod gingen die Diiodnorpinene 3a-c hervor. Dagegen erbrachte 7,7-Dibromtetracyclo[4.1.0.02,4.03,5]heptan (4) mit Brom das Tetrabrom-trans-tricyclo[4.1.0.02,4]heptan-Derivat 5. - Beim Belichten in Gegenwart von Thiophenol ergaben die Homobenzvalene 1a, c, e, f die 6-(Phenylthio)norpinene 6a-d. Die Hydroxyhomobenzvalene 1g, h lieferten überwiegend die 6-(Phenylthio)-norpinene 6e, g, deren Konfiguration an C-4 im Vergleich zu derjenigen von 6b-d invertiert ist. Der Einsatz von [D2]-1a zeigte, daß die Addition von Thiophenol stereochemisch nicht einheitlich verläuft. Bei der Einwirkung von Thiophenol auf 1a bei 20°C ohne Belichtung bildeten sich in langsamer Reaktion neben 6a auch die Norcaren-Derivate 9 und 10. - Die Umsetzung der Dichlorverbindung 6b mit LiAlH4 führte zur Monochlorverbindung 6h. 6b und mit besserer Ausbeute 6h gingen mit Natrium in flüssigem Ammoniak in unsubstituiertes Norpinen (11a) über, für das somit eine ergiebige neue Synthese zur Verfügung steht. Auf diese Weise wurden auch 6c, d in 4-Phenylnorpinen (11b) umgewandelt. Die Reaktionen der Norpinene 3a und 11a mit N-Bromsuccinimid ergaben die Allylbromide 3d und 11c. - Die 13C-NMR-Spektren der 4-substituierten Norpinene brachten einen diagnostisch wichtigen γ-anti-Substituenteneffekt an den Tag.
    Additional Material: 3 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19861191011
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    Tricyclo[5.1.0.02,8]oct-3-en, -oct-4-en und -octan: Darstellung und Thermolyse der Hydroderivate des Octavalens (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 3045-3058 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Tricyclo[5.1.0.02,8]-oct-3-ene, -oct-4-ene, and -octane: Preparation and Thermolysis of the Hydro Derivatives of OctavaleneOn treatment of 2,3,7,8-tetrabromobicyclo[4.1.1]oct-3-ene (7) with LiAlH4 an allylic rearrangement occurred with formation of tribromide 8, which was converted into 4-bromotricyclo[5.1.0.02,8]oct-3-ene (9) by n-butyllithium. Sodium/tert-butyl alcohol and 9 reacted to give tricyclo[5.1.0.02,8]oct-3-ene (4). Hydrogenation of 4 was achieved with diimine and afforded tricyclo[5.1.0.02,8]octane (6) along with some bicyclo[5.1.0]oct-2-ene (10). Sodium iodide transformed 7 into the unrearranged iodide 12. Reduction of 7 with sodium in liquid ammonia led to bicyclo[4.2.0]octa-3,7-diene (11) in low yield. An allylic rearrangement took place when 7 was treated with AgNO3 to give nitrate 13. In another allylic rearrangement tribromide 14 was formed from 13 and LiAlH4. The reaction of 14 with n-butyllithium afforded 4-bromotricyclo[5.1.0.02,8]oct-4-ene (15), and from 15 tricyclo[5.1.0.02,8]oct-4-ene (5) was obtained by means of sodium/tert-butyl alcohol. By treatment of 4-bromooctavalene (16) with tert-butyllithium and subsequent hydrolysis, a new route to octavalene (1) was elaborated with virtually no formation of cyclooctatetraene as side product. - At 100°C 4 rearranged (t1/2 ≍ 40 min) almost quantitatively to dihydrosemibullvalene (17). The decomposition of 5 at 200°C (t1/2 ≍ 25 h) gave a complex mixture, in which only 11 has been identified. The saturated hydrocarbon 6 was converted virtually quantitatively into a 5.5:1 mixture of 3-methylenecycloheptene (18) and 1,3-cyclooctadiene (19) at 160°C (t1/2 ≍ 8 h). Possible mechanisms of these rearrangements are discussed.
    Notes: 2,3,7,8-Tetrabrombicyclo[4.1.1]oct-3-en (7) ging mit LiAlH4 unter Allylumlagerung in das Tribromid 8 über, das bei der Einwirkung von n-Butyllithium 4-Bromtricyclo[5.1.0.02,8]oct-3-en (9) lieferte. Letzteres ergab mit Natrium/tert-Butylalkohol Tricyclo[5.1.0.02,8]oct-3-en (4). Die Hydrierung von 4 zu Tricyclo[5.1.0.02,8]octan (6) wurde mit Diimin ausgeführt und war von der Bildung von Bicyclo[5.1.0]oct-2-en (10) begleitet. Mit Natriumiodid brachte 7 das nicht umgelagerte Iodid 12 hervor, und die Reduktion von 7 mit Natrium in flüssigem Ammoniak führte in geringer Ausbeute zu Bicyclo[4.2.0]octa-3,7-dien (11). AgNO3 wandelte 7 unter Allylumlagerung in das Nitrat 13 um, das mit LiAlH4, wieder unter Allylumlagerung, das Tribromid 14 ergab. Bei der Behandlung von 14 mit n-Butyllithium fiel 4-Bromtricyclo[5.1.0.02,8]oct-4-en (15) an, und daraus wurde mit Natrium/tert-Butylalkohol Tricyclo[5.1.0.02,8]oct-4-en (5) gewonnen. Ein neuer Weg zu Octavalen (1), auf dem praktisch kein Cyclooctatetraen als Nebenprodukt entsteht, wurde durch Umsetzung von 4-Bromoctavalen (16) mit tert-Butyllithium und anschließende Hydrolyse gefunden. - Bei 100°C ging 4 praktisch quantitativ in Dihydrosemibullvalen (17) über (t1/2 ≍ 40 min). Der Zerfall von 5 lieferte bei 200°C (t1/2 ≍ 25 h) ein komplexes Gemisch, in dem nur 11 identifiziert wurde. Der gesättigte Kohlenwasserstoff 6 lagerte bei 160°C nahezu quantitativ in ein 5.5:1-Gemisch aus 3-Methylencyclohepten (18) und 1,3-Cyclooctadien (19) um (t1/2 ≍ 8 h). Mögliche Mechanismen dieser Thermolysen werden diskutiert.
    Additional Material: 2 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19861191012
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    Laserfarbstoffe, IV. Synthese planar fixierter Nonamethin-Cyaninfarbstoffe (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 3102-3108 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Laser Dyes, IV. Synthesis of Plane Rigidized Nonamethine Cyanine DyesThe one-pot synthesis of symmetrical and unsymmetrical nonamethine cyanine dyes 2 with a plane rigidized methine chain is described.
    Notes: Es wird ein Eintopf-Verfahren zur Darstellung von symmetrischen und unsymmetrischen Nonamethin-Cyaninfarbstoffen 2 mit planar fixierter Methinkette beschrieben.
    Additional Material: 2 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19861191017
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    Reaktionen der Cyclopropene, VII. Nickel(0)-katalysierte Cotrimerisierungen von 3,3-Dimethylcyclopropen mit Methylacrylat (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 3089-3101 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Cyclopropenes, VII. Nickel(0)-catalyzed Cotrimerisation of 3,3-Dimethylcyclopropene with Methyl AcrylateThe cotrimerisation of 3,3-dimethylcyclopropene (1) with methyl acrylate is catalyzed by phosphane- or phosphite-Ni(0) compounds under mild conditions (40-50°C). Depending on the nature of the phosphane or phosphite 1 and methyl acrylate cotrimerise mainly in the ratio 2:1 or 1:2 to give cis/trans-5 or cis/trans-6 and cyclic cis/trans-7. trans-5 and trans-6 are thermally more labile than the corresponding cis compounds. Heating to 200°C for two hours induces their complete rearrangement to 12 and 13 or 14 via 1,5-homodienyl-hydrogen shift.
    Notes: Triorganylphosphan- und -phosphit-haltige Nickel(0)-Verbindungen katalysieren die Cotrimerisierung von 3,3-Dimethylcyclopropen (1) mit Methylacrylat unter milden Bedingungen (40-50°C). In Abhängigkeit von der Art des Phosphans bzw. Phosphits entstehen bevorzugt offenkettige Cotrimere aus einem Mol 1 und zwei Mol Methylacrylat (cis/trans-5) oder offenkettige und cyclische Cotrimere aus zwei Mol 1 und einem Mol Methylacrylat (cis/trans-6 und cis/trans-7). trans-5 und trans-6 sind thermisch deutlich labiler als die entsprechenden cis-Derivate. Im Zuge einer 1,5-Homodienylwasserstoffwanderung lagern sie sich bereits nach zweistündigem Erhitzen auf 200°C quantitativ in die entsprechenden 1,4-Diene um (12 und 13 aus trans-5 bzw. 14 aus trans-6).
    Additional Material: 7 Tab.
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    Umlagerungen und komplexe Eliminierungen mit 1,5-Benzothiazepin-4-onen (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 3109-3120 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Rearrangements and Complex Eliminations with 1,5-Benzothiazepin-4-onesThe 1,5-benzothiazepin-4-ones 3, 5, and 7-10 are pyrolyzed (with proton catalysis in part). New or rarely documented rearrangements and complex eliminations occur. These are classified and mechanistically discussed. The products and by-products are spectroscopically characterized (IR, UV, NMR, MS). Their configurations are elucidated via photolysis experiments. 4 photodimerizes in solution and in the crystalline state with great ease to give 14. 11 is remarkably insensitive towards hydrolysis.
    Notes: Die 1,5-Benzothiazepin-4-one 3, 5 und 7-10 werden pyrolysiert (z. T. bei Protonenkatalyse). Es treten neue oder selten dokumentierte Umlagerungsreaktionen und komplexe Eliminierungsreaktionen auf, die klassifiziert und mechanistisch diskutiert werden. Die Produkte und Nebenprodukte werden spektroskopisch charakterisiert (IR, UV, NMR, MS) und mittels Photolyse in ihrer Konfiguration geklärt. 4 photodimerisiert sehr leicht in Lösung oder im Kristall zu 14. 11 ist erstaunlich hydrolyseunempfindlich.
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    Übergangsmetall-substituierte Acylphosphane und Phosphaalkene, IX. Zur Synthese von Phosphaalkenyl-, Mono- und Diacyl- phosphidokomplexen aus [Bis(trimethylsilyl)phosphido]-dicarbonyl(pentamethylcyclopentadienyl)eisen und Carbonsäurechloriden (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 1857-1867 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Transition-Metal-Substituted Acylphosphanes and Phosphaalkenes, IX. On the Synthesis of Phosphaalkenyl-, Mono- and Diacylphosphido Complexes from the Reaction of [Bis(trimethylsilyl)phosphido]dicarbonyl(pentamethylcyclopentadienyl)iron and Carbonyl ChloridesReaction of the title compound (η5-C5Me5)(CO)2FeP(SiMe3)2 (4) with 2,4,6-trimethylbenzoyl chloride (2a) yields the phosphaalkenyl complex (η5-C5Me5)(CO)2FeP=C(OSiMe3)(Mes) (5a). Treatment of 4 with benzoyl chloride affords the phosphaalkenyl complex 5b and (η5-C5Me5)(CO)2FeP[C(O)Ph]2 (6b), whereas with pivaloyl chloride (2c) 6c is formed as the sole product. The monoacylphosphido complexes 8a-c are generated from the reaction of 4 with acyl chlorides 2a-c in the presence of ethanol. Lithiation by LiCH3 and subsequent acylation with 2,4,6-trimethylbenzoyl chloride converts compound 8a into 6a. Similarily the lithiation product of 8 is transformed into the phosphaalkenyl complexes 5a-c by treatment with Me3SiCl.
    Notes: Die Titelverbindung (η5-C5Me5)(CO)2FeP(SiMe3)2 (4) reagiert mit 2,4,6-Trimethylbenzoylchlorid (2a) zu dem Phosphaalkenylkomplex (η5-C5Me5)(CO)2FeP=C(OSiMe3)(Mes) (5a). Demgegenüber führt die Umsetzung von 4 mit Benzoylchlorid neben dem Phosphaalkenylkomplex 5b zu (η5-C5Me5)(CO)2FeP[C(O)Ph]2 (6b). Aus 4 und Pivaloylchlorid (2c) wird nur noch der Dipivaloylphosphidokomplex 6c gebildet. Führt man die Umsetzungen von 4 mit den Säurechloriden 2a-c in Gegenwart von Ethanol durch, so erhält man die Monoacylphosphidokomplexe (η5-C5Me5)(CO)2FePH[C(O)R] (8a-c). Komplex 8a wird von Methyllithium lithiiert und durch 2,4,6-Trimethylbenzoylchlorid in 6a übergeführt. Desgleichen ergeben die Lithiierungsprodukte von 8 mit Me3SiCl die Phosphaalkenylkomplexe 5a-c.
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    Additionsreaktionen von 1,1-Dicyan-2,2-bis(trifluormethyl)ethen (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 3150-3157 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Addition Reactions of 1,1-Dicyano-2,2-bis(trifluoromethyl)etheneBy the reaction of the title compound (CF3)2C=C(CN)2 with PCl5 the (phosphoranyliden-amino)ethene 1 is obtained. The phosphorane 1 reacts with Me3SiNMe2 to form 2. WCl6 and MoCl5 react with (CF3)2C=C(CN)2 to give the acyclic nitrenes 3 and 4. The X-ray structure analysis of 3a, an acetonitrile adduct of 3, is reported.
    Notes: Die Titelverbindung (CF3)2C=C(CN)2 reagiert mit PCl5 zu dem (Phosphoranylidenamino)-ethen 1. Daraus entsteht 2 durch Reaktion mit Me3SiNMe2. Umsetzungen von (CF3)2C=C(CN)2 mit WCl6 und MoCl5 ergeben die acyclischen Nitrenkomplexe 3 und 4. Von 3a, einem Acetonitriladdukt von 3, wird eine Röntgenstrukturanalyse mitgeteilt.
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    URL: http://dx.doi.org/10.1002/cber.19861191022
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    Thieno[3,4-f]-2,1-benzisothiazol.  -  Synthese und physikalische Eigenschaften eines neuen kondensierten 14π-Heteroarens sowie dessen thermisches Cycloadditions-verhalten gegenüber N,N-Doppelbindungssystemen (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 3158-3164 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thieno[3,4-f]-2,1-benzisothiazole.  -  Synthesis and Physical Properties of a Novel Fused 14π Heteroarene as well as its Thermal Cycloaddition Reactions with N,N-Double Bond SystemsThe synthesis of the novel condensed title compound 2, which contains three masked dipolar systems, as well as its cycloaddition reactions with 1,2,4-triazoline-3,5-diones 3a, b and azo-dicarboxylic esters 5a, b with formation of 4 and 6, respectively, are described.
    Notes: Die Darstellung der neuen kondensierten Titelverbindung 2, die drei maskierte dipolare Systeme beinhaltet, sowie deren Cycloadditionen an 1,2,4-Triazolin-3,5-dione 3a, b und Azo-dicarbonester 5a, b unter Bildung von 4 bzw. 6 werden beschrieben.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19861191023
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    Electronic Resource
    Synthesis of benzo[1,2-b′:4,5-b′]dithiophene and its 4,8-Dimethoxy and 4,8-dimethyl derivatives (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 3198-3203 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthese von Benzo[1,2-b:4,5-b′]dithiophen und seinen 4,8-Dimethoxy- und 4,8-Dimethyl-DerivatenEine einfache Synthese für Benzo[1,2-b:4,5-b′]dithiophen (4) und die Synthese seines bisher unbekannten 4,8-Dimethoxy- (7) und 4,8-Dimethylderivates (13) wird beschrieben. IR-, 1H-NMR-, UV- und MS-Daten werden mitgeteilt.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19861191025
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