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  • 1
    Electronic Resource
    Electronic Resource
    Synthese und Konformationsanalyse von Pyranophanonen und Pyrylophanium-Verbindungen mit intraannularen Substituenten (1993)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 335 (1993), S. 503-514 
    Details
    ISSN: 0941-1216
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis and Conformational Analysis of Pyranophanones and Pyrylophanium Compounds with Intraannular SubstituentsThe synthesis of [3.3]dithiapyranophanone 6 and 11 is accomplished by use of the two-components-dilution-principle. Pyrolysis of their bis(sulfones) 7 and 12 gives the [2.2]pyranophanones 8, 9 and 13. Under preservation of conformation the intraannular carbonyl-function is used for the synthesis of methylpyranophanoles 14, 16 and 17. The synthesis of pyrylophanium compounds 15 and 18 is possible by elimination in trifluoroacetic acid.6 exhibits anti-conformation within its crystal-structure and like 7 reveals temperature-dependent behavior in solution. Using 6 as an example, a combination of 13C-NMR-spectroscopy, forcefield-calculation and computer-simulation is applied for the first time to give evidence for molecular-dynamic processes of cyclophanes.8 and 9 are the syn- and anti-conformers of the desired product, as shown by X-ray structural analysis. 13 reveals anti-conformation within its crystal structure as well as in solution. The conformational analysis of other new phanes described here is based on the 1H-NMR-spectra of these pyrolysis products.As expected the intraannular substituents of Pyrylophanium-lons 15 and 18 show the characteristic upfield-shift within their 1H-NMR-spectra.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19933350603
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  • 2
    Electronic Resource
    Electronic Resource
    Reactions of 3,5-Diaryl-1,2-dithiolium Salts and 3,5-Diaryl-1,2,4-dithiazolium Salts with Metal Cyclopentadienides (1997)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1997 (1997), S. 221-228 
    Details
    ISSN: 0947-3440
    Keywords: 3,5-Diaryl-1,2-dithiolium salts ; 3,5-Diaryl-1,2,4-dithiazolium salts ; Metal cyclopentadienides ; 3,7-Dithiatricyclo[4.4.0.02,8]deca-4,9-diene ; 3,5-Dithiatricyclo[4.2.2.02,6]deca-7,9-diene ; 3,7-Dithia-5-azatricyclo[4.4.0.02,8]deca-4,9-diene ; Diels-Alder reactions ; Nitrogen heterocycles ; Sulfur heterocycles ; Polycycles ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reaction of the 3,5-diaryl-1,2-dithiolium salts 2 with the metal cyclopentadienides 4 and 9 leads to the formation of the tricyclic compounds 6 and 10 via a ring-opened intermediate, which undergoes an intramolecular Diels-Alder cyclization. Compounds 6 and 10 rearrange by treatment with boron trifluoride-diethyl ether to the isomeric compounds 7 and 11. The structures 6f and 7f were confirmed by X-ray analysis. Condensation of the 3,5-diaryl-1,2,4-dithiazolium salts 3 with the metal cyclopentadienides 4 affords the tricyclic compounds 12, which do not rearrange by Lewis acid catalysis.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.199719970133
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  • 3
    Electronic Resource
    Electronic Resource
    Positional and Facial Selectivity in Diels-Alder Reactions of (-)-(aS,7S)-Colchicine: Synthesis of Novel Analogues of the Alkaloid (1997)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1997 (1997), S. 851-857 
    Details
    ISSN: 0947-3440
    Keywords: Colchicine, diene properties of ; Positional selectivity ; Stabilized exciplex through hydrogen bonding ; π-Facial diastereoselectivity ; Photooxygenation ; Solvent effects ; Cycloadditions ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Positional and facial selectivity in Diels-Alder reactions of several hetero- and carbodienophiles with (-)-(aS,7S)-colchicine (1) has been examined. In all cases, cycloaddition occurred with high positional selectivity at the 8,12-positions of the alkaloid and preferentially from the diene face syn to the allylic substituent at the stereogenic center C-7. The observed high π-facial diastereoselectivity is independent of the polarity of the solvent used and is therefore probably a consequence of steric factors. The structures of the Diels Alder-adducts of 1 with singlet oxygen, N-phenyl-1,2,4-triazolinedione (PTAD) and trans-cyclooctene, 4,5, and 15, respectively, were assigned on the basis of spectral data and verified by X-ray crystallography.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.199719970510
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  • 4
    Electronic Resource
    Electronic Resource
    Synthesen mit aliphatischen Dialdehyden, XLII. (2,4,6-Cycloheptatrien-1-yliden)malonaldehyd (8,8-Diformylheptafulven)  -  Herstellung, Struktur und Reaktionen (1985)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1985 (1985), S. 1997-2011 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses with Aliphatic Dialdehydes, XLII.  -  (2,4,6-Cycloheptatrien-1-ylidene)malonaldehyde (8,8-Diformylheptafulvene)  -  Synthesis, Structure, and Reactions8,8-Diformylheptafulvene (5) was synthesized for the first time by hydride abstraction from sodium salts of(cycloheptatrienyl)malonaldehydes (2 and 3). In solution, 5 exists in a solventdependent equilibrium with its valence isomer 6. The structure of 5 was determined by means of its 1H and 13C NMR spectrum, dipole moment (5.24 D), and an X-ray analysis; its dipole moment and chemical reactivity were also estimated by MNDO calculations.  -  Reactions of 5 with electrophiles (→7) and with nucleophiles (→ 8 - 14 are described.
    Notes: 8,8-Diformylheptafulven (5) wurde zum ersten Mal hergestellt durch Hydridabstraktion aus (Cycloheptatrienyl)malonaldehyd-Natriumsalzen (2 und 3). 5 steht in Lösung mit dem Valenzisomeren 6 in einem lösungsmittelabhängigen Gleichgewicht. Die Struktur von 5 wurde durch 1H- und 13C-NMR-Spektrum, Dipolmoment (5.24 D) sowie eine Röntgenstrukturanalyse gesichert; Dipolmoment und chemische Reaktivität wurden auch durch MNDO-Berechnungen abgeschätzt. - Reaktionen von 5 mit Elektrophilen (→7) und mit Nucleophilen (→8 - 14) werden beschrieben.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198519851008
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  • 5
    Electronic Resource
    Electronic Resource
    Synthesen mit aliphatischen Dialdehyden, XL. (2,4,6-Cycloheptatrien-1-yl)malonaldehyd - Herstellung, Struktur und Reaktionen (1985)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1985 (1985), S. 1969-1986 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses with Aliphatic Dialdehydes, XL. - (2,4,6-Cycloheptatrien-1-yl)malonaldehyde - Synthesis, Structure, and ReactionsTropylation of the sodium salt of malonaldehyde with cycloheptatrienylium tetrafluoroborate yielded the enolized, s-trans-configurated (2,4,6-cycloheptatrien-1-yl)malonaldehyde (1) for the first time. Reaction of 1 with anilines leads to the 3-anilino-2-propenals 3 and 4 with Fischer's base to the pentamethine cyanine dye 5, with maleic anhydride and tetracyanoethylene to the cycloadducts 6 and 7, and with bifunctional N-nucleophiles to the cycloheptatrienyl-substituted heterocycles 10 - 12. The structures of 3 and 5 were determined by means of X-ray analyses.
    Notes: Tropylierung des Malonaldehyd-Natriumsalzes mit Cycloheptatrienylium-tetrafluoroborat ergab erstmals den enolisierten, s-trans-konfigurierten (2,4,6-Cycloheptatrien-1-yl)malonaldehyd (1). Umsetzungen von 1 mit Anilinen führen zu den 3-Anilino-2-propenalen 3 und 4, mit dem Fischerbase-Quartärsalz zum Pentamethincyanin-Farbstoff 5, mit Maleinsäureanhydrid und Tetracyanethylen zu den Cycloaddukten 6 und 7, und mit bifunktionellen N-Nucleophilen zu den cycloheptatrienlylsubstituierten Heterocyclen 10 - 12. Die Struktur von 3 und 5 wurde röntgenographisch ermittelt.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198519851006
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  • 6
    Electronic Resource
    Electronic Resource
    A Novel Cycloocta[d]-/Barreleno[d]pyridazine RearrangementDedicated to Prof. Dr. Dr. h.c. F. Eiden on the occasion of his 70th birthday. (1995)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1995 (1995), S. 661-666 
    Details
    ISSN: 0947-3440
    Keywords: Cyclooctatetraene-bicyclooctatriene valence tautomerism ; [4+2] Cycloadditions, inverse ; Cycloocta[d]pyridazine ⇛ barreleno[d]pyridazine rearrangement ; [1, 3]-Carbon migration ; Catalysis, 1,3-tautomerization with 2-hydroxypyridine ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: As part of the valence tautomeric system cyclooctatetraene (2) bicyclo[4.2.0]octa-2,4,7-triene (3), the monocyclic polyene (2) reacts as a dienophile with the diazadiene 3,6-bis(trifluoromethyl)-1,2,4,5-tetrazine (1) to form after N2-elimination two products: The 1 : 1-adduct 6, a cycloocta[d]pyridazine, and the tetracyclic bis-Diels-Alder cycloadduct 9. Depending on solvent polarity and temperature, compound 6 displays interesting novel rearrangements. On refluxing in nonpolar solvents like toluene, compound 6 yields the barreleno[d]pyridazine 13 in high yield. Compound 13 can be oxidized with 4-phenyltriazolinedione 14 to the barreleno[d]pyridazine 15. When the more polar nitromethane is used as a solvent, heating of 6 at 90° 2°C surprisingly leads to the dihydrocycloocta[d]pyridazine 18 in a multistep reaction including proton-shift tautomerism and [1, 5]-sigmatropic rearrangement. The structures of the compounds 15 and 18 were assigned by the spectral data and verified by X-ray crystallography.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.199519950493
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  • 7
    Electronic Resource
    Electronic Resource
    Diels-Alder Reactions of (1H-Indol-3-yl)-enacetamides and -endiacetamides: A Selective Access to Acetylamino-Functionalized [b]Annelated Indoles and CarbazolesThis work is dedicated to Prof. Dr. Dr. Ernst Mutschler, Frankfurt/Main, on the occasion of his 60th birth day. (1991)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 74 (1991), S. 727-738 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Diels-Alder reactions of the (1H-indol-3-yl)-enacetamides and -endiacetamides 1a-d with some carbodieno-philes and 4-phenyl-3H-1,2,4-triazole-3,5(4H)-dione give rise to the novel amino-functionalized carbazole; 4-6 and 8 (Scheme 3). Ethenetetracarbonitrile reacts with 1b to furnish the Michael-type adduct 7 (Scheme 3). Structural aspects of the starting materials 1, which exhibit above all 3-vinyl-1H-indole reactivity, are discussed with regard to the prediction of a Diels-Alder process.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19910740406
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  • 8
    Electronic Resource
    Electronic Resource
    Hochsubstituierte Cyclopentadiene mit Arylthio- und Arylsulfonyl-Gruppen (1991)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1991 (1991), S. 243-251 
    Details
    ISSN: 0170-2041
    Keywords: Cyclopentadienes, highly substituted ; Sulfonyl group migration ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Highly Substituted Cyclopentadienes with Arylthio and Arylsulfonyl GroupsCyclopentadienes 1 react with diaryl disulfides 2 to form the tetrakis(arylthio)cyclopentadienides 3, which have been oxidized with m-chloroperbenzoic acid to give the tetrakis(arylsulfonyl)cyclopentadienides 5. Protonation of 5 yields the tetrakis(arylsulfonyl)cyclopentadienes 7 by migration of arylsulfonyl groups. Oxidation of 3 by iodine leads to the dihydropentafulvalenes 11. By reaction of 3 with arylthiosulfonates 14 the pentakis(arylthio)cyclopentadienes 15 have been obtained. Their salts 16 may be oxidized to form the pentakis(arylsulfonyl)cyclopentadienides 17, or condensed with sulfenyl chlorides to give the hexakis(arylthio)cyclopentadienes 19. The structure of the phenylthio compound 19a was confirmed by an X-ray structure analysis.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.199119910142
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  • 9
    Electronic Resource
    Electronic Resource
    Oxidationen an Thiourethanen, 10. Synthese, Kristallstruktur, Oxidation und Photochemie der Thion-S-oxide cyclischer Dithiourethane und Dithiocarbazate (1992)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1992 (1992), S. 337-344 
    Details
    ISSN: 0170-2041
    Keywords: Sulfines ; Thione S-oxides ; Dithiourethanes ; Dithiocarbazates ; Thioxiran intermediates ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Oxidations of Thiourethanes, 10.  -  Synthesis, Crystal Structure, Oxidation and Photochemistry of Thione S-Oxides of Cyclic Dithiourethanes and DithiocarbazatesSeveral cyclic dithiocarbamates and dithiocarbazates (2-4) have been oxidised with mCPBA to give the corresponding thione S-oxides 5-7. The sulfine structure was confirmed by oxidation to the corresponding oxo derivatives and X-ray crystal structure analysis. Photolysis of the sulfines gave the corresponding oxo as well as the thioxo derivatives. The isolation of both the oxo and the thioxo derivatives is reported here for the first time, it provides an other evidence for the postulated thioxirane intermediate in the photolysis of sulfines.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.199219920160
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