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  • Cell & Developmental Biology  (873)
  • Inorganic Chemistry  (785)
  • Wiley-Blackwell  (1,658)
  • 1985-1989  (1,658)
  • 1915-1919
  • 1985  (1,658)
Collection
Keywords
Publisher
  • Wiley-Blackwell  (1,658)
Years
  • 1985-1989  (1,658)
  • 1915-1919
Year
  • 1
    Electronic Resource
    Electronic Resource
    Non-actin filaments and cell contraction in Kofoidinum and other Dinoflagellates (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 1-15 
    Details
    ISSN: 0886-1544
    Keywords: contractile non-actin filaments ; dinoflagellates ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The motility and fine structure of the marine planktonic dinoflagellate Kofoidinium and members of other related genera have been investigated. Several types of shape change were found to occur: slow morphogenetic changes (which also occurred as restitution movements in response to injury), movements associated with the ingestion of food and the evacuation of wastes, and more rapid movements concerned with the capture of prey. All these movements seemed to be brought about by the contraction of refractile tracts within the cytoplasm, which were found to contain 2.3-nm filaments, some with a complex striated appearance. This and other evidence suggests that these filaments, which have counterparts in many other protists, are not actin filaments.
    Additional Material: 22 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970050102
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  • 2
    Electronic Resource
    Electronic Resource
    Masthead (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985) 
    Details
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970050201
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  • 3
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    Analysis of the morphology and function of primary cilia in connective tissues:A cellular cybernetic probe? (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 175-193 
    Details
    ISSN: 0886-1544
    Keywords: primary cilia ; connective tissues ; secretory organelles ; extracellular matrix ; cybernetic probe ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: More than 300 primary cilia have been identified electronmicroscopically in a variety of embryonic and mature connective tissue cells. To further define the enigmatic function of these cilia, we examined the interrelationships between the basal apparatus and cytoplasmic organelles and the ciliary shaft and the extracellular matrix. The basal diplosome was consistently associated with the secretory organelles including the maturing face of the Golgi complex, Golgi vacuoles and vesicles, the microtubular network, the plasma membrane, and coated pits and vesicles. Small vesicles and amorphous granules were also observed within the ciliary lumen and adjacent to the ciliary membrane. Microtubule-membrane bridges linked axonemal tubules to the ciliary membrane. The position, projection, and orientation of the axoneme were influenced by the structural organisation and mechanical properties of the matrix and frequently caused angulation of the ciliary shaft relative to the basal body. Located midway between the secretory apparatus and the extracellular matrix, primary cilia would appear ideally situated to mediate the necessry interaction between the cell and its surrounding environment prerequisite to the formation and maintenance of a functionally effective matrix. We propose that primary cilia in connective tissue cells could act as multifunctional, cellular cybernetic probes, receiving, transducing, and conducting a variety of extrinsic stimuli to the intracellular organelles responsible for effecting the appropriate homeostatic feedback response to changes in the extracellular microenvironment.
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970050302
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  • 4
    Electronic Resource
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    Proteins closely similar to flagellar tektins are detected in cilia but not in cytoplasmic microtubules (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 239-249 
    Details
    ISSN: 0886-1544
    Keywords: tektins ; microtubules ; flagella ; cilia ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Affinity-purified antibodies against Strongylocentrotus purpuratus sperm flagellar tektin polypeptides have been tested for cross-reactivity with microtubules isolated from various sources, using indirect immunofluorescent staining and antibody binding to nitrocellulose replicas of SDS polyacrylamide gels. The antitektins reacted with sperm tail axonemes from four genera of sea urchins and with cilia from sea urchin embryos. Antibody binding was observed only if the specimens were prefixed by methods that would not preserve them well at an ultrastructural level. However, even after such fixation regimes, no antibody binding was detected to cytoplasmic microtubule arrays in the same embryos, to mitotic spindles isolated from sea urchin or to gill cilia from a mollusc. We conclude that, if tektins are present in sea urchin egg cytoplasmic microtubules, they are sufficiently different from the sperm tektins to have no common strongly antigenic determinants.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/cm.970050306
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  • 5
    Electronic Resource
    Electronic Resource
    Live and reactivated motility in the 9 + 0 flagellum of Anguilla sperm (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 333-350 
    Details
    ISSN: 0886-1544
    Keywords: eel sperm ; 9+0 flagellum ; motility ; helicoidal bending ; reactivation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The sperm flagella of the eel, Anguilla anguilla, are capable of vigorous motion in spite of having an axoneme with reduced structure that lacks the outer dynein arms, radial spokes and spoke heads, the two central tubules and the central tubule projections that are all part of the standard “9+2” axoneme. These sperm progress forward rapidly as a result of the propagation of helicoidal waves distally along the flagellum. Their flagellar beat frequencies are high, 93 Hz at 21°C, and they roll at a frequency of about 19 Hz. Eel sperm could be demembranated with Nonidet P-40 and reactivated with MgATP2- in 0.22 M K acetate at pH 8.1. The reactivated motility closely resembles that of the live sperm, with a beat frequency of 69 Hz, but the demembranated flagella are unusually fragile, and commonly disintegrate by a combination of splitting, coiling, and sliding within a few minutes. Little reactivation is obtained if acetate is replaced by Cl- in the reactivating medium. The Michaelis constant for beat frequency (0.2 mM) is similar to that obtained for several “9+2” flagella. These sperm, however, appear to lack the mechanism by which Ca2+ regulates waveform. Our results indicate that eel sperm flagella, which at rest are straight, are induced to bend helicoidally by ATP, as the result of sliding between tubules that is blocked at both the base and tip of the organelle. The flagellar waveform consists of a series of planar bends separated by short regions of right-handed twist, which give it an overall left-handed helicoidal form.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970050406
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  • 6
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    Newt lung ciliated cell models: Effect of MgATP on beat frequency and waveforms (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 377-392 
    Details
    ISSN: 0886-1544
    Keywords: newt ; lung ; cilia ; beat frequency ; waveform ; models ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Highly coupled newt lung ciliated cell models were used to study the effects of MgATP concentration on ciliary beat frequency and waveform. Models were prepared from ciliated lung cells of the newt Taricha granulosa by trypsin dissociation of the epithelium, demembranation with Triton X-100, and reactivation with MgATP, as described previously [Weaver and Hard, 1985]. Beat frequencies were measured stroboscopically. Ciliary waveforms of reactivated models and intact mucociliary epithelial sheets were determined by single frame analysis of high-speed movies. Waveform parameters calculated included the durations of the effective and recovery strokes, the angular velocities of the ciliary base and tip, the position of the bend along the ciliary shaft during the recovery stroke, the velocity of recovery stroke bend propagation, and the ratio of the duration of recovery stroke bend propagation to the duration of the recovery stroke itself. We found that beat frequency varied biphasically in response to MgATP at 21°C, as shown previously for isolated, individual, newt lung axonemes. Apparent Fmax (maximum beat frequency) and Km values of 25 Hz and 0.14 mM, and 35 Hz and 0.47 mM, respectively, were obtained for each linear segment of the biphasic double reciprocal plot. Demembranation did not alter either ciliary waveform or the pattern of coordination. In this system, metachrony is antilaeoplectic and ciliary waveform appears to be regulated independent of beat frequency.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970050503
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  • 7
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    Reorientation of the golgi apparatus and the microtubule-organizing center inside macrophages subjected to a chemotactic gradient (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 17-29 
    Details
    ISSN: 0886-1544
    Keywords: cell motility ; membrane recycling ; immunofluorescence microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Mouse peritoneal macrophages subjected to gradients of activated mouse serum were found by immunofluorescence observations to have their Golgi apparatus and their microtubule-organizing center largely oriented in the direction of the gradient. By analogy with similar results obtained with motile fibroblasts, it is proposed that these two organelles are rapidly and coordinately reoriented inside the macrophages in order to direct the insertion of new membrane mass, via vesicles derived from the Golgi apparatus, into the leading edge of the cell. Consistent with the importance of such membrane insertion to cell migration, we found that the ionophore monensin, an inhibitor of Golgi functions, inhibited cell motility in the chemostactic gradient. It was further shown that several inhibitors of chemotaxis (monensin, cytochalasin D, cycloheximide) did not inhibit the reorientation of the Golgi apparatus/microtubule-organizing center in cells exposed to a chemotactic gradient, and that the reorientation required extracellular Ca+2.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970050103
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  • 8
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    Alpha actinin distribution and extracellular matrix products during somitogenesis and neurulation in the chick embryo (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 491-506 
    Details
    ISSN: 0886-1544
    Keywords: Somitogenesis ; neurulation ; alpha-actinin ; morphogenesis ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A discrete stage in two different morphogenetic processes has been examined employing fluorescently labelled alpha-actinin as a probe to localize native alpha-actinin and antibodies to localize fibronectin and collagen type I. The stage of somitogenesis examined is the transition from the compact mesenchymal somitic mass to the epithelial somitic vesicle (ie, epithelialization of the somite). The stage of neurulation examined is the transition from the relatively flat neuroepithelium to the approximation of the neural folds. Before these morphogenetic movements begin, the neuroepithelium is sitting upon a basal lamina and interstitial collagen, and the somite is surrounded by a meshwork of interstitial collagen. During both of these processes, the cells become narrowed at their apices in the region of the tissue that is becoming concave, and alpha-actinin is localized in the apices. The localization of intracellular alpha-actinin and extracellular fibronectin, and the distribution of collagen, suggest that there is a coordinated appearance and distribution of these molecules that is temporally associated with these discrete morphogenetic events.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/cm.970050606
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  • 9
    Electronic Resource
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    Bending patterns of Chlamydomonas flagella: III. A radial spoke head deficient mutant and a central pair deficient mutant (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 195-208 
    Details
    ISSN: 0886-1544
    Keywords: central pair ; radial spoke ; flagella ; mutant ; Chlamydomonas ; suppressor ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Flash photomicrography at frequencies up to 300 Hz and computer-assisted image analysis have been used to obtain parameters describing the flagellar bending patterns of mutants of Chlamydomonas reinhardtii. All strains contained the uni1 mutation, to facilitate photography. The radial spoke head deficient mutant pf17, and the central pair deficient mutant, pf15, in combination with suppressor mutations that restore motility without restoring the ultrastructural or biochemical deficiencies, both generate forward mode bending patterns with increased shear amplitude and decreased asymmetry relative to the “wild-type” uni1 flagella described previously. In the reverse beating mode, the suppressed pf17 mutants generate reverse bending patterns with large shear amplitudes. Reverse beating of the suppressed pf15 mutants is rare. There is a reciprocal relationship between increased shear amplitude and decreased beat frequency, so that the velocity of sliding between flagellar microtubules is not increased by an increase in shear amplitude. The suppressor mutations alone cause decreased frequency and sliding velocity in both forward and reverse mode beating, with little change in shear amplitude or symmetry.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/cm.970050303
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  • 10
    Electronic Resource
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    Masthead (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985) 
    Details
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970050401
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  • 11
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    Erratum (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 265-265 
    Details
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/cm.970050308
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  • 12
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    The locomotion of dissociated sponge cells: A cell-by-cell, time-lapse film analysis (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 463-473 
    Details
    ISSN: 0886-1544
    Keywords: sponge dissociates ; cell migration ; time-lapse analysis ; cell aggregation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The production of both lamellipodia and peculiar thin protuberances (scleropodia) characterizes the preaggregative motility of cells after dissociation of the sponge Clathrina.The locomotory paths taken by cells before aggregation were recorded by time-lapse microcinematography. Changes of direction in successive 50-s time intervals and 50-s mean velocities of each cell were both taken into account as statistical variables. Their distributions give probability density curves that seem to fit bilateral exponential functions. The analysis of the angles of turn indicates a tendency for the cells to persist in their direction of motion and to make counter-clockwise turns. Implications of such in vitro cellular behaviors in aggregative and in vivo processes are suggested.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/cm.970050604
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  • 13
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    Video microscopy of fast axonal transport in extruded axoplasm: A new model for study of molecular mechanisms (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 81-101 
    Details
    ISSN: 0886-1544
    Keywords: fast axonal transport ; isolated axoplasm ; video microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The development of AVEC-DIC microscopy and the application of this method to the study of fast axonal transport in isolated axoplasm extruded from the giant axon of the squid Loligo pealei provides a new paradigm for analyzing the intracellular transport of membranous organelles. The size of the axon, the number of transported particles, and the absence of permeability barriers like the plasma membrane in this preparation permit many experiments that are difficult or impossible to perform using other model systems. The use and features of this preparation are described in detail and a number of properties are evaluated for the first time. The process of extrusion is characterized. Particle movement is evaluated both in the interior of extruded axoplasm and along individual fibrils that extend from the periphery of perfused axoplasm. The role of divalent cations, particularly Ca2+, and the effects of elevated Ca2+ on axoplasmic organization and transport are analyzed. A series of pharmacological agents and polypeptides that alter cytoskeletal organization are used to examine the role of microfilaments and microtubules in fast transport. Finally, the effects of depleting ATP and of adding ATP analogues are discussed. The extruded axoplasm preparation is shown to be an invaluable model system for biochemical and pharmacological analyses of the molecular mechanisms of intracellular transport.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/cm.970050203
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  • 14
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    Tension in the culture dish: Microfilament organization and migratory behavior of quail neural crest cells (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 225-237 
    Details
    ISSN: 0886-1544
    Keywords: neural crest ; migratory behavior ; microfilaments ; stress fibers ; tractional force ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: We have investigated one aspect of the migratory behavior of quail neural crest (NC) cells by comparing the organization of microfilament bundles and the ability to distort migratory substrata by NC, somite, and notochord cells in vitro. In contrast to the numerous cytoplasmic stress fibers in somite-derived fibroblasts and notochord cells revealed by rhodamine-phalloidin staining and thin-section electron microscopy, microfilaments in NC cells are restricted to the cell cortex. To test the relative degrees of tension generated by these cell types on the underlying substratum, cells were cultured in collagen gels and on distortable silicone rubber sheets. Explanted somites and notochords produced dramatic radial alignment of 750 μg/ml collagen gels, whereas neural crest cells only aligned gels of lower concentrations. Fibroblasts did not migrate individually from explanted somites and notochords into 250 μg/ml collagen gels as readily as into higher concentration collagen lattices. In contrast, neural crest cells migrated into matrices of low concentration as well as into higher concentration collagen gels. Neural crest cells and their pigmented derivatives did not distort silicone rubber sheets, whereas somite and notochord-derived fibroblasts wrinkle this substratum after 4 days in culture. Thus, the differences in organization of the actin cytoskeleton reflect the tractional force exerted by these cells on their substratum. We hypothesize that the migratory behavior of NC cells in vivo may be related to their ability to translocate through embryonic extracellular matrices while generating relatively weak adhesions with the substratum, whereas the stronger forces generated by other embryonic cell types upon the delicate extracellular matrix may restrict their migration and may be associated with other morphogenetic events.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/cm.970050305
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  • 15
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    Masthead (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985) 
    Details
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970050101
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  • 16
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    Flow birefringence of microtubules and its relation to birefringence measurements in cells (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 31-51 
    Details
    ISSN: 0886-1544
    Keywords: microtubules ; birefringence ; flow birefringence ; tubulin ; polarization microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Understanding the molecular basis of mitotic movements in living cells will require correlative experiments on intact cells, cell models, purified tubulin, and perhaps other biopolymers. Birefringence is one assay that is useful in all of these experimental situations. Heretofore, studies of birefringence changes during mitosis have lacked a quantitiative basis for interpretation in terms of microtubule number and packing density. One of the aims of this work was to establish that relationship.Purified calf brain tubulin was polymerized to equilibrium and oriented in the hydrodynamic field of a microcapillary flow birefringence apparatus. The relationship between birefringence and microtubule packing density was determined by a combination of optical, electron microscopic, and biochemical methods. The data correlate surprisingly well with those obtained by others from in vitro measurements on isolated mitotic spindles. Using the flow birefringence data, the sensitivity of polarizing microscopes for detecting microtubules was examined and found to depend on microtubule packing density, object thickness, and instrumental factors that limit both the detection and measurement of weakly birefringent objects. Because of the dependence of measurement sensitivity on object thickness, a method of measuring the thickness of microtubule bundles using the dispersion of birefringence was developed. This method is capable of measuring thickness to within two or three Airy diffraction units and does not require any assumptions regarding object symmetry.
    Additional Material: 11 Ill.
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    URL: http://dx.doi.org/10.1002/cm.970050104
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  • 17
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    Obituary (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. i 
    Details
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970050202
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  • 18
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    Study of the properties of MgATP2--induced stationary bends in demembranated sea urchin sperm (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 209-224 
    Details
    ISSN: 0886-1544
    Keywords: flagellar dynein ; cyclic nucleotides ; sperm activation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Methods of demembranation and reactivation of Lytechinus pictus sperm were developed that result in non-motile sperm which take on a stable bend of about 3.5 radians at the proximal end of the cell. The middle and distal portion of the flagellum is relatively straight or slightly bent in the same direction forming a somewhat “C” shaped sperm cell. In these studies, we refer to this characteristic shape as the quiescent form, and as opposed to “rigor wave” sperm, the quiescent form is induced and maintained by a relatively high concentration of MgATP2- (〉 0.2 mM). Other conditions important to the production and maintenance of the quiescent form in demembranated sperm include: starting with concentrated, undiluted sperm, maintaining low Ca++ in the demembranation buffer, using a minimum of 0.2 mM MgATP2- and pH of 7.9-8.1 in the reactivation buffer. Deviation from some of these conditions results in a dramatic increase in motile, asymmetrically beating sperm. Addition of 0.4 mM CaCl2 to the reactivation buffer increased the proximal bend angle to 5 radians. The induction and maintenance of the stationary bend is mediated by dynein activity: “rigor wave” sperm were transformed to the quiescent form upon 0.2 mM ATP addition; micromolar vanadate abolished the quiescent form by “relaxation” of the proximal bend; and the vanadate relaxed sperm were restored to quiescent form by catechol. Importantly, 20 μM cAMP activated motility of the otherwise quiescent-form sperm. Quiescent-form, demembranated sperm were also activated by mild trypsin digestion. These and other data suggest that the quiescent-form sperm are trapped at the end of the principal bend, and these data are consistent with the proposal that the single stationary bend results from asymmetry of active microtubule sliding [Gibbons and Gibbons, (1980): J. Cell Biol. 84:13-27].
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/cm.970050304
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  • 19
    Electronic Resource
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    A versatile and quantitative computer-assisted photoelectronic technique used for the analysis of ciliary beat cycles (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 267-292 
    Details
    ISSN: 0886-1544
    Keywords: mammalian cilia ; respiratory tract ; mucociliary clearance ; laterofrontal cirri ; Mytilus edulis ; beat cycle ; computer analysis ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The beat cycles of rabbit tracheal cilia in culture and Mytilus laterofrontal cirri were recorded using a phototransistor, transillumination, video, and phase-contrast microscopy. The photoelectronic signal and video image of the ciliary activity were simultaneously recorded as a composite image. The photoelectronic signal was converted into a digital signal by a data acquisition system for further computer processing.By the selection of a small detector area and accurate detector alignment, a simple, repetitive photoelectronic signal representing ciliary activity was obtained. This signal records the ciliary beat frequency and demonstrates the triphasic nature of the beat cycle. The photoelectronic signal can be precisely correlated with the ciliary activity by analysis of the composite video recordings to provide the duration of the effective, recovery, and rest phases of the beat cycle. The videophotoelectronic signal correlations were verified by high-speed cinematography. High-speed films of ciliary activity were digitized, and the image density of selected pixels was analyzed by computer with respect to time and ciliary motion.These studies indicate that duration of the phages of the beat cycle are differentially reduced with increased beat frequency; the effective phase duration was quickly reduced to a minimum. This was followed by the reduction of the duration of the recovery phase to a minimum. The rest phase continues to be reduced without reaching a minimum, over the range of beat frequencies observed. These results suggest that ciliary beat frequency may be regulated either by modifying the rates of dynein-microtubule interactions or the rate of transition from one beat phase to the next.
    Additional Material: 12 Ill.
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    URL: http://dx.doi.org/10.1002/cm.970050402
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  • 20
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    Masthead (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985) 
    Details
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970050501
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  • 21
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    Anouncement (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 351-354 
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    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970050407
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    Masthead (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985) 
    Details
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970050601
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    Orthokinetic and klinokinetic responses of human polymorphonuclear leucocytes (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 447-461 
    Details
    ISSN: 0886-1544
    Keywords: chemokinesis ; orthokinesis ; klinokinesis ; polymorphonuclear leucocytes ; locomotion ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Evidence is presented to show that klinokinesis, which was previously demonstrated in bacteria and amoeba only, may also occur in metazoan cells. The chemotactic peptide formyl-Met-Leu-Phe (fMLP) elicited orthokinetic and klinokinetic responses of human blood-borne polymorphonuclear leucocytes (PMNs) under the test conditions used. Increased speed (orthokinesis) was due to an increase in the proportion of migrating cells as well as in the speed of the locomoting subset. The klinokinetic effect was manifested by a decrease in the klinolocomotion index, the mean angle of changes in direction ≥ 90°, and the frequency of turns ≥ 90°. The klinolocomotion index was inversely related to speed. This explains the synergistic effect of klinokinesis and orthokinesis in this system. Colchicine alone had and orthokinetic effect which was exclusively due to alterations in the proportion of migrating cells and it altered the turning behaviour without exerting a klinokinetic effect. However, colchicine had marginal orthokinetic and klinokinetic effects on fMLP-stimulated cells resulting in reduced translocation. The relationship between klinokinesis and mean angle or frequency of turns has been analysed. Klinokinesis was a substantial though not the major element of the chemokinetic response to fMLP under the conditions used. No other metazoan cells have been shown to possess such a complete pattern of responses, including orthokinesis, klinokinesis, and chemotaxis, which regulate locomotion.
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    A Ca2+ insensitive actin-crosslinking protein from Dicytostelium discoideum (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 529-543 
    Details
    ISSN: 0886-1544
    Keywords: actin ; regulatory protein ; cytoskeleton ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: We have isolated a 30,000-dalton protein from Dictyostelium which cosedimented with and affected the low shear viscosity of actin. At low concentrations, this protein increased the low shear viscosity to greater than that of the actin control, whereas higher concentrations decreased viscosity. The viscosity decrease correlated with the formation of actin filament bundles, as seen electron microscopically. This protein resembled a previously reported actin-binding protein from Dictyostelium [Fechheimer and Taylor, 84, J Biol Chem 259:4514] in electrophoretic mobility, Stokes radius, and ability to crosslink filaments, but was shown to be different by peptide mapping, lack of immunologic crossreactivity, and lack of sensitivity to calcium.
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    A model for fast axonal transport (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 507-527 
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    ISSN: 0886-1544
    Keywords: axonal transport ; microtubules ; organelles ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A model for fast axonal transport is developed in which the essential features are that organelles may interact with mechanochemical cross-bridges that in turn interact with microtubules, forming an organelle-engine-microtubule complex which is transported along the microtubules. Computer analysis of the equations derived to describe such a system show that most of the experimental observations on fast axonal transport can be simulated by the model, indicating that the model is useful for the interpretation and design of experiments aimed at clarifying the mechanism of fast axonal transport.
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    Fundamental problems of movement of cilia, eukaryotic flagella, and related systems: A seminar held under the U.S. Japan cooperative science program (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 137-173 
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    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
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    URL: http://dx.doi.org/10.1002/cm.970050206
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    An approach to digital image analysis of bending shapes of eukaryotic flagella and cilia (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 475-489 
    Details
    ISSN: 0886-1544
    Keywords: digital image processing ; flagella ; cilia ; bends ; Hemicentrotus ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A novel method of digital image analysis of the bends of eukaryotic flagella and cilia was devised. In the analysis system, all image pixels were systematically extracted and processed to measure angular direction and curvature. Simulation experiments on theoretical model pictures of flagella with sine-generated or arcstraight line bending waves demonstrated that the method can be used with considerable high accuracy. This method then revealed abrupt changes in slope of the curvature in sperm flagella and embryo cilia of the sea urchin, Hemicentrotus pulcherrimus. This indicates that the digital image processing used may be helpful in the study of flagellar and ciliary movements.
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    An EHNA-senstive ATPase in unfertilized sea urchin eggs (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 61-75 
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    ISSN: 0886-1544
    Keywords: dynein ; erythro-9-[3-2-(hydroxynonyl)]adenine (EHNA) ; ATPase ; inhibition ; axoneme ; cytoplasm ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In current purification strategies, affinity for microtubules or calmodulin is used to identify and purify cytoplasmic dynein-like ATPase from cell-free extracts of unfertilized sea urchin eggs. However, affinity purification procedures, though they define dynein-like ATPase activity, have not yet proven to be quantitative. An alternative purification strategy capable of producing a high yield of enzyme would require a specific assay in order to monitor cytoplasmic dynein purity at each step.In this study, we make a detailed comparison of the effects of EHNA on 22 different ATP-metabolizing enzyme activities, including 13 Mg++-ATPases. We isolate cytoplasmic dynein-like ATPase activity from three species of sea urchin eggs and sperm and show by means of dose-response curves that their sensitivities to inhibition by EHNA are very similar to one another. We demonstrate further that the EHNA dose-response characteristics of fourteen other ATP-metabolizing enzyme activities, including seven nondynein Mg++-ATPases, differ quantitatively from those of dynein-like ATPases.In studies of three other agents (vanadate, Ca++/calmodulin, and Triton X-100), we find that dynein-like ATPases vary by two orders of magnitude in their sensitivities to inhibition by vanadate, and little or no stimulation by either Ca++/calmodulin or Triton X-100 is seen. Our results suggest that inhibition by EHNA is a universal and specific property of dynein-like ATPases, which ultimately should prove useful in the quantitative purification and characterization of cytoplasmic dynein-like ATPase (s).
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    An investigation of the involvement of cytoskeletal structures and secretion in gliding motility of the marine diatom, Amphora coffeaeformis (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 103-122 
    Details
    ISSN: 0886-1544
    Keywords: gliding ; cell motility ; cytoskeleton ; diatoms ; capping ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Gliding motility was investigated in the marine diatom, Amphora coffeaeformis. Ultrastructural, biochemical, and pharmacological protocols were employed to probe the possible involvement of cytoskeletal proteins and a secretory process in gliding motility. Motility rate was measured using a video recording apparatus, and the effects of various cytoskeleton-disrupting drugs on motility were tested. Cytochalasins D and E, podophyllotoxin, and vinblastine (all at 25 μUg/ml) reversibly inhibited motility, as did monensin (10 μUM) and pronase (25 μUg/ml). Biochemical protein analysis of whole-cell extracts by one- and two-dimensional polyacrylamide gel electrophoresis revealed polypeptides comigrating with rabbit skeletal muscle actin and bovine brain tubulin; however, specific assays used to separate actin from whole-cell preparations gave ambiguous results. Ultrastructural studies revealed the presence of extracellular material between the raphe canal and the substratum in motile cultures. An assay was devised for the detection of radioactively labeled material (MW 〉 1800 Daltons) released by motile cultures into the culture medium. When cultures were treated with either an anticytoskeletal drug or monensin, motility was inhibited while the amount of measured radioactivity increased over solvent-treated control groups. The results from this study indicate possible roles for both actin- and tubulin-based structures in gliding motility of Amphora. Though secretion may be necessary for gliding to occur, its exact relationship to motility was not deduced. The data obtained in this study are compatible with a theory for the mechanism of gliding which involves the surface translocation of externally exposed membrane proteins against an immobile matrix of substratum-attached secreted material to generate the force required for movement.
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    Ionic control of locomotion and shape of epithelial cells: I. Role of calcium influx (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 123-136 
    Details
    ISSN: 0886-1544
    Keywords: locomotion and shape control ; epithelial cells ; calcium ; reflection-interference contrast-microscopy ; cinematography ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The role of calcium in the induction of locomotion, control of direction of locomotion, and modulation of shape of epithelial cells derived from Xenopus laevis tadpole epidermis is investigated. Local influx of calcium is achieved by electrophoretic release of small amounts of calcium from a micropipette (tip diameter 0.1-0.5 μUm) closely apposed to the cell body or lamella. The cells are made permeable for calcium by calcium ionophore A23187, and they are kept in Ca++-free, Mg++-rich EGTA Ringer. Another method used to induce Ca++ influx is local application of A23187 while cells move in normal culture medium.Influx of Ca++ into the lamella induces a localised increase in thickness and enlargement of the lamella. Stationary cells become active and show movement in the direction of the Ca++ gradient. Fried-egg-shaped cells tend to acquire a semicircular shape and start moving. Moving cells change the direction of their locomotion, following the direction of Ca++ release. Influx of Ca++ in the cell body region induces its contraction concomitant with an increase in lamellar area.These observations suggest the presence of two different Ca++-sensitive components: an actomyosin meshwork in the cell body and an actin gel in the lamella. Influx of Ca++ induces contraction of actomyosin and solation of actin gel. Interaction of these two systems would explain modulation of shape and generation of locomotion in epithelial cells.
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    Masthead (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985) 
    Details
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970050301
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    The antagonistic effects of 5-hydroxytryptamine and methylxanthine on the gill cilia of mytilus edulis (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 293-309 
    Details
    ISSN: 0886-1544
    Keywords: Mytilus edulis ; 5-hydroxytryptamine ; lateral cilia ; laterofrontal cirri ; beat frequency ; methylxanthine ; filter-feeding ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The laterofrontal (LF) cirri on isolated gill filaments of Mytilus edulis, prepared in natural seawater, are active and initially beat with an average frequency of about 8 Hz (with a range of 6-14 Hz). However, the lateral (L) cilia on these filaments are arrested in a position at the end of their recovery stroke. Perfusion of the filament with artificial seawater (ASW), with or without 1% ethanol, has little or no biological effect on the activity of the LF cirri, although a transitory decrease in frequency often accompanies the perfusion process. The L cilia remain arrested during perfusion with ASW. The exposure of the gill to low levels of 5-hydroxytryptamine (5HT) (10-8 〈 5HT 〈 10-7 M) has no effect on the activity of the LF cirri but stimulates the L cilia to beat. Exposure to higher concentrations of 5HT (〉 10-7 M) elevates the beat frequency of the L cilia and simultaneously inhibits the activity of the LF cirri, leading to their arrest in a position at the end of the effective stroke. This arrest of the LF cirri occurs as the L cilia attain a 5HT-induced beat frequency between 12 to 14 Hz. The influence of 5HT on the L cilia and the LF cirri can be reversibly mimicked or enhanced by the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (IBMX). A concentration of 0.5 mM IBMX mimics low 5HT concentrations (about 10-7 M) by stimulating the L cilia to beat without affecting the beat frequency of the LF cirri. A combimation of 10-7 M 5HT and 0.5 mM IBMX in ASW mimics high (〉 10-6 M) 5HT concentrations by arresting the LF cirri and increasing the beat frequency of the L cilia. Under these conditions, the threshold of the LF cirri arrest response is again found to occur as the L cilia attain a beat frequency of 12 - 14Hz. These results suggest that the mechanisms of LF cirri arrest and L cilia activation are mediated by 5HT -induced changes in intracellular cyclic AMP levels.
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    Chromosome movement during meiotic prophase in crane-fly spermatocytes: III. Microtubules and the effects of Colcemid, nocodazole, and vinblastine (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 393-413 
    Details
    ISSN: 0886-1544
    Keywords: chromosome movement ; Colcemid ; nocodazole ; meiotic prophase ; microtubules ; vinblastine ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The effects of Colcemid, nocodazole, and vinblastine on microtubules and on the movement of chromosomes during late diakinesis were investigated in spermatocytes of the crane fly Nephrotoma suturalis. The kinds of movements observed in untreated cells - sex bivalent rotations, sex bivalent excursions, and rotations and positional changes of autosomal bivalents - also were observed in drug-treated cells. These results were obtained in living cells in which the disruption and inhibition of microtubule assembly had been confirmed with polarized light microscopy. Effects of Colcemid and nocodazole also were assessed in fixed cells using electron microscopy. The results are in agreement with a hypothesis that microtubules are not a force-generating component of the molecular machinery that brings about prophase movements.
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    Bending patterns of Chlamydomonas flagella: II. Calcium effects on reactivated Chlamydomonas flagella (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 53-60 
    Details
    ISSN: 0886-1544
    Keywords: calcium ; Chlamydomonas ; flagella ; motility ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Ca2+ has profound effects on the movement of cilia and eukaryotic flagella, including those of Chlamydomonas. Two clear changes seen in Chlamydomonas flagella with changes in Ca2+ are beat frequency and symmetry. Photographic and computer assisted analysis of flagellar bending patterns on a uniflagellate mutant of Chlamydomonas have been used to examine details of the effects of Ca2+ on the movement of ATP-reactivated, demembranated flagella. In addition to the forward mode bending pattern seen at low Ca2+ concentrations (10-9 M), which has a frequency of about 50 Hz and the reverse mode bending pattern seen at high Ca2+ concentrations (10-4 M) with a frequency around 70 Hz, we carefully examined bending patterns in the intermediate Ca2+ concentration range of 1-6.5 × 10-6 M. In this intermediate range, the bending patterns have significantly reduced asymmetry and slightly increased frequency, compared to the motility observed at low Ca2+ concentrations. These observations indicate that changes in these two parameters of motion do not occur in parallel and suggest that the effects of Ca2+ may be a multicomponent process. Physiologically, these changes in the beat pattern at intermediate Ca2+ may signal either (1) the beginning stages of transition to the symmetrical, high-frequency beating seen at high Ca2+, or (2) a more normal forward mode motility for the trans flagellum as suggested by Kamiya and Witman [1984]. No large amplitude bending patterns associated with transitions between forward and reverse mode beating in intact cells were seen at the intermediate Ca2+ concentrations.
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    Localization of actin in Chlamydomonas using antiactin and NBD-phallacidin (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 415-430 
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    ISSN: 0886-1544
    Keywords: Actin ; immunofluorescence ; NBD-phallacidin ; Chlamydomonas ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: We have localized actin in gametes of Chlamydomonas reinhardi by two approaches: (1) indirect immunofluorescence with an affinity-purified antibody and (2) staining with NBD-phallacidin, a fluorescent reagent that binds only to F-actin [Barak et al, 1980, Proc Natl Acad Sci, 77:980-984]. Staining of either mating type “plus” (mt+) or “minus” (mt-) gametes with antiactin antibody resulted in similar fluorescent images: most of the actin was located peripherally along the lateral and posterior aspects of the cells. There was diffuse staining centrally, but the flagella did not stain. No brightly stained spot was observed near the mt+ mating structure, the site where the fertilization tubule elongates with concomitant polymerization of actin [Detmers et al, 1983, J Cell Biol, 97:522-532]. Gametes stained prior to mating with NBD-phallacidin showed no fluorescence above background, indicating that there were no concentrations of F-actin in these cells. This suggested that the cytoplasmic staining observed with antiactin represented primarily a nonfilamentous form of the protein. In mating gametes staining with NBD-phallacidin was detected only in the fertilization tubule, indicating that this was the only dense accumulation of filamentous actin within the cells. Mating gametes stained with antiactin antibody exhibited cytoplasmic fluorescence that was slightly more punctate than prior to mating, and the fertilization tubule was brightly stained. Our observations suggest that the site-specific polymerization of actin within the fertilization tubule occurs in the absence of a concentrated pool of actin subjacent to the mating structure.
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    A Method for quantifying F-Actin in chemotactic peptide activated neutrophils: Study of the effect of tBOC peptide (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 545-557 
    Details
    ISSN: 0886-1544
    Keywords: neutrophils ; cytoskeleton ; actin polymerization ; NBDphallacidin ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The studies presented here characterize a simple, quantitative NBDphallacidin extraction assay for determining the F-actin content of fMLP-activated neutrophils. The NBDphallacidin extraction assay is based upon the specificity of NBDphallacidin binding to F-actin and the solubility of NBDphallacidin in methanol. Cells are fixed, permeabilized, and stained with NBDphallacidin; the cells are then pelleted, the bound NBDphallacidin is extracted into methanol, and the RFI (excite 465; emit 535) of the solution is determined. Binding of NBDphallacidin to neutrophils is saturable and 90% of bound NBDphallacidin is displaced by nonfluorescent phalloidin. The extraction of bound NBDphallacidin into methanol is complete and the excitation/emission characteristics of NBDphallacidin are not altered by extraction. The assay is relatively inexpensive, applicable to the study of cells in suspension or on substratum, allows kinetic studies with 5-10s time resolution, and is not affected by the shape of the cell or the distribution of the probe. We used the NBDphallacidin extraction assay to study the kinetics of fMLP-induced change in the F-actin content of neutrophils and the effect of tBOC peptide, an inhibitor of fMLP binding, on these changes. The extraction assay reveals a rapid, sequential fMLP-induced increase followed by a decrease in F-actin content. The tBOC peptide inhibits fMLP-induced actin polymerization. Addition of tBOC during fMLP-induced polymerization or at times when F-actin content is maximal enhances F-actin depolymerization. The rate of F-actin depolymerization is ≥ fourfold faster in the presence than in the absence of tBOC. The results show that (1) The NBDphallacidin extraction assay is useful for studying the kinetics of change in F-actin content of nonmuscle cells; (2) fMLP receptor occupancy is required for fMLP-dependent polymerization but not depolymerization; and (3) both the actin polymerizing and depolymerizing processes are active in the cell within 5 s after fMLP stimulation. Implications of these observations for understanding the observed increase and, then, decrease in F-actin content of fMLP-activated cells are discussed.
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    Actin assembly and filament cross-linking in the presence of TW 260/240, the tissue-specific spectrin of the chicken intestinal brush border (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 311-322 
    Details
    ISSN: 0886-1544
    Keywords: Spectrin ; TW 260/240 ; chicken intestinal brush border ; actin assembly ; actin filament cross-linking ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: TW 260/240 is a tissue-specific spectrin found in the terminal web region of the chicken intestinal bruish border. We have examined the effects of TW 260/240 on assembly rates and critical concentrations (Co's) for monomer addition at the barbed and pointed ends of the actin filament. For these studies, acrosomal processes (AP) from Limulus sperm were used as nuclei for actin assembly. Under conditions which favor the interaction of TW 260/240 for actin (20-75 mM KCl, 2 mM Mg++) no effect on either elongation rates or Co's at either end of the actin filament was observed in the presence of this spectrinlike protein. The Limulus AP nucleation assay also allowed visualization of the kinetics of filament binding and cross-linking by TW 260/240. Ultrastructural analysis of TW 260/240 binding to actin filaments at their growing ends indicates that TW 260/240 tetramers bind laterally to the filament. Finally, evidence is presented that indicates that filaments cross-linked by TW 260/240 are stabilized against shear-dependent breakage.
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    Tetrahymena cell model exhibiting Ca-dependent behavior (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 323-331 
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    ISSN: 0886-1544
    Keywords: Tetrahymena ; cell model ; ATP concentration ; Ca sensitivity ; backward swimming ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Using Tetrahymena pyriformis, strain w, and Tetrahymena thermophila, B-1868, we prepared cell models that showed ciliary reversal with change in Ca-ion concentration, as was also noted for the Paramecium cell model. No differences could be found between these two strains in the reactivation state, and their response to environmental conditions was essentially the same. The reactivation rate was 90% or more. Swimming velocity of the cell model was found to be 200 ± 49 μm/sec at 25.0°C ± 0.5°C, while the velocity for the living cells was 527 ± 101 μm/sec. Swimming velocity with change in environmental conditions, such as pH, Mg-ATP, and Ca-ion concentrations, was studied. Compared to the cell model of Paramecium, the Tetrahymena cell model had higher sensitivity toward Ca-ion in the reactivation medium. The effects of chlorpromazine, and inhibitor of calmodulin, on the swimming behavior of the cell models were studied.
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    Use of multiple monoclonal antibodies to characterize the major microtubule-associated protein in sea urchin eggs (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 431-446 
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    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Microtubules assembled from sea urchin eggs with the use of taxol contain a 77,000-dalton protein as the major nontubulin component [Vallee and Bloom (1983): Proc Natl. Acad. Sci. U.S.A. 80:6259-6263]. We have raised five monoclonal antibodies to this protein to aid in its characterization. Immunoblot analysis of the sea urchin microtubule purification fractions indicated that the protein copurified quantitatively with microtubules. All five antibodies stained the mitotic spindle of dividing sea urchin eggs by immunofluorescence microscopy, indicating that the protein was a component of the mitotic spindle and suggesting that it was actually localized on microtubules in vivo. Immunofluorescent staining of higher resolution was observed in a subpopulation of the coelomic cells found in adult sea urchins, confirming that the 77,000-dalton protein is indeed present on microtubules in vivo. Because taxol was not used for the immunofluorescence experiments, we conclude that the microtubule-associated protein (MAP)-like behavior of the 77,000-dalton protein in vitro was not induced artifactually by taxol. To determine whether this protein is a component of sea urchin microtubules in general, cilia obtained from blastula stage embryos and sperm tail flagella were analyzed with the antibodies. The protein was undetectable by both immunoblot analysis and immunofluorescence microscopy in both preparations of axonemal microtubules. These results indicated that the 77,000-dalton MAP is restricted to cytoplasmic and mitotic microtubules in the sea urchin. Furthermore, in view of its particular abundance in embryos, whose microtubules are devoted substantially to mitosis, the 77,000-dalton MAP is likely to play an important role in regulating the activity of mitotic spindle microtubules in the sea urchin.
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    High-speed cinematographic analysis of the movement of Chlamydomonas (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 251-263 
    Details
    ISSN: 0886-1544
    Keywords: Chlamydomonas ; movement ; flagellar beat ; stigma ; high-speed microcinematography ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Using high-speed microcinematography (100-500 f/s) the movement of Chlamydomonas reinhardtii mutant 622 E has been studied with frame-by-frame analysis. The stigma lies in the cell equator, displaced out of the flagellar plane anticlockwise by an angle of about 45°. During forward movement the cells rotate anticlockwise about their long axis with a frequency of 1.4-2 Hz (maximum 2.5 Hz). The rotation is caused by a lateral component of 3-dimensional beating of the flagella during the effective strokes. The helical swimming path is a result of an unequal flagellar beating. This is normally synchronous, but synchrony is interrupted from time to time by an additional beat of the outward directed flagellum, in our study one after about every twenty beats on average. These results are discussed and compared with the results published by other groups.
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    Isolation of newt lung ciliated cell models: Characterization of motility and coordination thresholds (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 355-375 
    Details
    ISSN: 0886-1544
    Keywords: Newt ; lung ; cilia ; cell models ; ciliary coordination ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Demembranated ciliated cell models are useful for studying mechanisms responsible for the regulation of ciliary coordination and waveform. This paper describes procedures for isolating ciliated cells from the newt, Taricha granulosa, by trypsin dissociation, their subsequent demembranation by Triton X-100, and their reactivation with MgATP to produce highly motile, coordinated, ciliated cell models. Reactivation of cell models with a high degree of mechanochemical coupling depended on avoiding mechanical damage and maintaining optimal conditions during all stages of isolation and reactivation. Highly motile models were prepared from cells incubated in trypsin, treated briefly with EDTA, separated by gentle agitation, and concentrated by centrifugation at low gravitational forces. Optimal demembranation and reactivation conditions were similar to those described previously for isolated newt lung axonemes. Under these conditions, nearly 100% of the models were reactivated when provided with MgATP and 90-95% beat with coordinated waves. The ciliary tufts beat at frequencies within the range measured in living cells and their reactivated motility was stable for at least 30 min at constant MgATP. These highly coupled models were used to show (1) that development of coordination in the ciliary tuft occurs at a higher substrate concentration range (10-25 μM) than that required to initiate motility per se (2-10 μM); (2) that outer dynein arms may not contribute to beat frequency at substrate concentrations below 35 μM; and (3) that vanadate has effects both on beat frequency and coordination of the tufts.
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    Synthese, Struktur und katalytische Aktivität von μ-(Alkylthio)-dicarbonyl-μ-chloro-bis(tri-tert-butylarsan)-dirhodium-Komplexen (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 2738-2745 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis, Structure, and Catalytic Activity of μ-(Alkylthio)-dicarbonyl-μ-chloro-bis(tri-tert-butylarsane)dirhodium ComplexesTetracarbonyl-di-μ-chloro-dirhodium (1) reacts with tri-tert-butylarsane (2) and alkyl trimethylsilyl sulfides (4) to give complexes [Rh2(CO)2(AstBu3)2Cl(SR)] (5a-c). The complexes 5b and c with the surface active trialkoxysilyl groups [R=(MeO)3SiCH2CH2, (MeO)3SiCH2CH2CH2] are bound to fused silica support. The X-ray structural analysis of[Rh2(CO)2(AstBu3)2Cl(StBu)] (5a) indicates a cis-configuration of the tri-tert-butylarsane ligands. The new complexes catalyze the hydroformylation of cyclohexene, and the isomerization of allylbenzene (8) into cis- and trans-β-methylstyrene (9). The soluble complex 5a was shown to be an extremely effective olefin hydrogenation catalyst, whereas the supported complexes 6b and c were completely inactive in this process.
    Notes: Durch Umsetzung von Tetracarbonyl-di-μ-chloro-dirhodium (1) mit Tri-tert-butylarsan (2) und Alkyl(trimethylsilyl)sulfiden (4) werden die Komplexe [Rh2(CO)2(AstBu3)2Cl(SR)] (5a-c) dargestellt. Die Komplexe 5b und c mit Trialkoxysilyl-Gruppen [R=(MeO)3SiCH2CH2, (MeO)3SiCH2CH2CH2] werden auf Silicagel fixiert. Die Röntgenstrukturanalyse von [Rh2(CO)2- (AstBu3)2Cl(StBu)] (5a) zeigt das Vorliegen von cis-konfigurierten Tri-tert-butylarsan-Gruppen. Die neuen Komplexe katalysieren die Hydroformylierung von Cyclohexen und die Isomerisierung von Allylbenzol (8) zu cis- und trans-β-Methylstyrol (9). Während lösliches 5a die Hydrierung von Olefinen katalysiert, sind die Heterogenkatalysatoren 6b und c hierbei völlig inaktiv.
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    Brückenkopf-olefinische Isomere des Triquinacens: Derivate des Tricyclo[5.2.1.04,10]deca-1,5,8- und -1,6,8-triens (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 2757-2776 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Bridgehead Olefinic Isomers of Triquinacene: Derivatives of Tricyclo[5.2.1.04,10]deca-1,5,8- and -1,6,8-trieneBridgehead halides 12 and 13 of triquinacene (2) with soft nucleophiles undergo a syn-stereoselective SN2′ reaction forming derivatives of tricyclo[5.2.1.04,10]deca-1,5,8-triene 15 and 17, respectively, and of tricyclo[5.2.1.04,10]deca-1,6,8-triene 18. The relative stability of these bridgehead olefins is discussed with regard to force field calculations as well as semiempirical MNDO calculations.
    Notes: Brückenkopf-Mono- 12 und -Dihalogenide 13 des Triquinacens (2) reagieren mit weichen Nucleophilen im Sinne einer syn-stereoselektiven SN2′-Reaktion zu Derivaten des Tricyclo[5.2.1.04,10]-deca-1,5,8-triens 15 bzw. 17 und des Tricyclo[5.2.1.04,10]deca-1,6,8-triens 18. Die relative Stabilität dieser Brückenkopf-Olefine wird anhand von Kraftfeld-Rechnungen sowie semiempirischen MNDO-Rechnungen diskutiert.
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    URL: http://dx.doi.org/10.1002/cber.19851180718
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    Stabilitätskonstanten und thermodynamische Werte für die Bildung von 1:1- und 2:1-Komplexen von Kronenethern mit Alkali- und Erdalkali-Ionen in Methanol (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 2746-2756 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stability Constants and Thermodynamic Values for the Formation of 1:1- and 2:1-Complexes of Crown Ethers with Alkali and Alkaline-earth Ions in MethanolThe determination of stability constants and thermodynamic values for the reaction of crown ethers with alkali-, alkaline-earth ions, and the silver ion was achieved by calorimetric titration in methanol. Through modification of the experimental conditions it is possible to measure separately the formation of 1:1- and 2:1-complexes (ratio of ligand to cation). With the exception of Ag+ and Ca2+ all ions examined form both kinds of complexes with the various 15 C 5 ligands. The complex stabilities are influenced by enthalpic and entropic contributions. 18 C 6 and DC 18 C 6, having a bigger diameter than 15 C 5, show a definite increase of the stability of 1:1-complexes. Only the Cs+ ion with the largest radius forms 2:1-complexes. A good agreement is found with values determined potentiometrically for the 1:1- and 2:1-complex formation of Na+.
    Notes: Die Komplexstabilitäten und thermodynamischen Werte für die Reaktion von Kronenethern mit Alkali-, Erdalkali-Ionen und dem Silber-Ion in Methanol wurden mittels kalorimetrischer Titrationen bestimmt. Durch Veränderung der experimentellen Bedingungen ist es möglich, sowohl die Bildung von 1:1- als auch 2:1-Komplexen (Verhältnis von Ligand zu Kation) getrennt voneinander zu messen. Mit Ausnahme von Ag+ und Ca2+ bilden alle untersuchten lonen beide Arten von Komplexen mit den verschiedenen 15 K 5-Liganden. Die Komplexstabilitäten werden von enthalpischen und entropischen Faktoren beeinflußt. 18 K 6 und DC 18 K 6, die einen größeren Durchmesser als 15 K 5 besitzen, zeigen einen deutlichen Anstieg der Stabilität der 1:1-Komplexe. 2:1-Komplexe bildet nur noch das Cs+ -Ion mit dem größten Radius. Ein Vergleich mit potentiometrisch bestimmten Daten für die 1:1- und 2:1-Komplexbildung von Na+ zeigt gute Übereinstimmung.
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    Anodische Oxidation O-benzoylierter α-Hydroxyessigsäuren - Ein Beitrag zur Reaktivität anodisch umgepolter Carboxylat-Ionen (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 2777-2788 
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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: Anodic Oxidation of O-Benzoylated α-Hydroxyacetic Acids - A Contribution to the Reactivity of Anodic Oxidated Carboxylate Ions - “Umpolung”Anodic oxidation of O-benzoylated α-hydroxyacetic acid 1 at graphite electrodes in methanol leads to the corresponding mixed acylals 2 and methyl benzoates 3. The rate 2:3 depends on the substitution of the aromatic ring and can be correlated to Hammett's σ-values.
    Notes: Bei der anodischen Oxidation O-benzoylierter α-Hydroxyessigsäuren 1 an Graphitelektro-den in Methanol entstehen die zugehörigen gemischten Acylale 2 und die entsprechenden Benzoesäure-methylester 3. Das Produktverhältnis 2:3 ist abhängig von der Substitution des Aromaten und läßt sich mit den Hammettschen σ-Werten korrelieren.
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    Cyclopentadienylsubstituierte Germylene und Stannylene als Komplexliganden (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 2789-2797 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cyclopentadienyl-substituted Germylenes and Stannylenes as Complex LigandsTransition metal complexes of chloro(pentamethylcyclopentadienyl)germylene and -stannylene with pentacarbonylchromium and -tungsten bound to the 4B-element (3a, b, 5a, b) are available by alkylation of the ylide complexes Cl2(THF)El→M(CO)5 (El=Ge, Sn; M=Cr, W, 1a, b, 4a, b). X-Ray structure studies on the germylene complex Me5C5(Cl)-Ge→ W(CO)5 (3b) show that involving the lone-pair of the 4B-element in a metal-metal bond changes the distorted h5-Me5C5 coordination of the uncomplexed germylene to a highly symmetrical h2-structure.
    Notes: Übergangsmetallkomplexe des Chlor(pentamethylcyclopentadienyl)germylens und -stannylens mit am 4B-Element gebundener Pentacarbonylchrom- bzw. -wolframeinheit (3a, b, 5a, b) werden durch Alkylierung der Ylidkomplexe Cl2(THF)El→M(CO)5 (El=Ge,Sn; M=Cr, W, 1a, b, 4a, b) erhalten. Röntgenographische Untersuchungen am Germylenkomplex Me5C5(Cl)Ge→W(CO)5 (3b) zeigen, daß sich die Inanspruchnahme des “lone-pair” am 4B-Element in einem Wechsel der verzerrten h5-Me5C5-Koordination im freien Germylen zu einer hochsymmetrischen h2-Koordination äußert.
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    URL: http://dx.doi.org/10.1002/cber.19851180720
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    Kleine Ringe, 52. Oxidative Ringöffnung von Tetra-tert-butyltetrahedran. - Kristall- und Molekularstruktur von Tetra-tert-butyl-cyclobutenylium-Ionen (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 2798-2810 
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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: Small Rings, 52. Oxidative Ring Opening of Tetra-tert-butyltetrahedrane. - Crystal and Molecular Structure of Tetra-tert-butylcylobutenylium IonsOxidative ring opening of tetra-tert-butyltetrahedrane yields cyclobutenylium ions of type 4 or 6. Their spectroscopic properties, but especially the crystal structure determination of 4h and 6c, show the characteristics expected for homocyclopropenylium salts. Because of 1,3-bonding interactions the ions are folded (4h: 37.3°, 6c: 36.4°), the 1,3-distances across the four-membered ring are short (4h: 1.806 Å, 6c: 1.833 Å).
    Notes: Bei der oxidativen Ringöffnung von Tetra-tert-butyltetrahedran entstehen Cyclobutenylium-Salze vom Typ 4 oder 6. Deren spektroskopische Eigenschaften, vor allem aber röntgenographische Strukturbestimmungen von 4h oder 6c, rechtfertigen es, diese Verbindungen als Homocyclopropenylium-Salze zu benennen. Die Ionen sind aufgrund von 1,3-bindenden Wechselwirkungen stark gefaltet (4h: 37.3°, 6c: 36.4°), der 1,3-Abstand im Vierring ist kurz (4h: 1.806 Å, 6c: 1.833 Å).
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    Tetrafluor-1,2-ethandisulfenyldichlorid - ein Baustein für neue Schwefel-Stickstoff-Kohlenstoff-Heterocyclen (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 2811-2821 
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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: Tetrafluoro-1,2-ethanedisulfenyl Dichloride - a Precursor for new Sulfur-Nitrogen-Carbon Heterocycles1,3,2-Dithiazolidines (3a-c) are obtained by reaction of the title compound CISCF2CF2SCI 1 with disilylated amines (Me3Si)2NR (R=Me, Ph, SiMe3). Reaction with (Me3-SiNR)2SO2 (R=Me, SiMe3) yields 1,3,5,2,4-trithiadiazepanes 4a, b, whereas N,N′-disilylated urea leads to the dithiadiazepanon 5. CISCF2CF2SSCI and SO2[N(SiMe3)2]2 react to yield the eight-membered tetrahiadiazocane 6. Using the dilution principle, with disilylated piperazine 7 in a molar ratio of 1:1 the sixteen-membered ring 9 is formed, which contains two piperazine units within the ring skeleton. The crystal structure of 1,3,5,2,4-trithiadiazepane-tetraphenylphosphonium chloride 10 is reported. 4b reacts with 1 to yield 11 in which a ten-membered ring is bridged by an SO2 group. By changing the reaction conditions a product of twice the molecular weight is formed, for which a tricyclic system with a central fourteen-membered ring 13 is proposed.
    Notes: Die Titelverbindung CISCF2CF2SCI 1 reagiert mit disilylierten Aminen (Me3Si)2NR (R=Me, Ph, SiMe3) glatt zu 1,3,2-Dithiazolidinen (3a-c). Bei der Umsetzung mit (Me3SiNR)2SO2 (R=Me, SiMe3) werden die 1,3,5,2,4-Trithiadiazepane 4a, b erhalten; mit N,N′-disilyliertem Harnstoff bildet sich das 1,5,2,4-Dithiadiazepanon 5. CISCF2CF2SSCI und SO2[N(SiMe3)2]2 reagieren zum achtgliedrigen 1,2,4,6,3,5-Tetrathiadiazocan 6. Durch Anwendung des Verdünnungsprinzips wird mit disilyliertem Piperazin 7 im Molverhältnis 1:1 der sechzehngliedrige Ring 9 synthetisiert, welcher zwei Piperazineinheiten im Ringgerüst enthält. Von 1,3,5,2,4-Trithiadiazepan-Tetraphenylphosphoniumchlorid 10 wird die Röntgenstrukturanalyse mitgeteilt. 4b reagiert mit 1 zu 11; hier liegt ein zehngliedriger Ring vor, der durch eine SO2-Gruppe überbrückt ist. Bei veränderter Reaktionsführung erhält man ein Produkt der doppelten Molekülmasse, dem eine tricyclische Struktur zugeschrieben wird, die einen zentralen vierzehngliedrigen Ring enthält (13).
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    Darstellung und Eigenschaften von 1,3-Dithietan-2-on-1,1-dioxid (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 2852-2857 
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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: Preparation and Properties of 1,3-Dithietan-2-one 1,1-DioxideOzonolysis of 2-(benzoylmethylene)-1,3-dithietane 1,1-dioxide (7), prepared via oxidation of 2-(benzoylmethylene)-1,3-dithietane (6), yielded 1,3-dithietan-2-one 1,1-dioxide (5) as the first 1,3-dithietane with an α-oxosulfone structure. Diethyl (1,3-dithietan-2-ylidene)malonate S,S-dioxide (2) did not react with ozone. 5 can be regarded as a potential sulfene precursor. However, in the pyrolysis of 5 sulfene could not be detected so far.
    Notes: Ozonolyse von 2-(Benzoylmethylen)-1,3-dithietan-1,1-dioxid (7), dargestellt durch Oxidation von 2-(Benzoylmethylen)-1,3-dithietan (6), ergab 1,3-Dithietan-2-on-1,1-dioxid (5) als erstes 1,3-Dithietan mit α-Oxosulfonstruktur. (1,3-Dithietan-2-yliden)malonsäure-diethylester-S,S-dioxid (2) setzte sich dagegen nicht mit Ozon um. 5 kann als potentieller Sulfen-Bildner angesehen werden. Bei der Pyrolyse von 5 konnte jedoch bislang kein Sulfen nachgewiesen werden.
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    Cycloadditionen des 1-(4-Methoxyphenyl)-2,2-dimethylvinyl-Kations an Olefine (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 2974-2992 
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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: Cycloadditions of 1-(4-Methoxyphenyl)-2,2-dimethylvinyl Cation to Olefins1-Bromo-1-(4-methoxyphenyl)-2-methyl-1-propene (1) reacts with cyclohexene, cycloheptene, (Z)-cyclooctene and the silver salts AgBF4, via the vinyl cation 2 by cycloaddition to form the cyclobutenes 7b-d. Cyclobutene 8 is obtained from (Z)- and (E)- and (E)-2-butene. Besides the cyclobutene derivatives, the isomeric cyclopropane compound 10d is also formed in the reaction of 1 with (Z)-cyclooctene under the same conditions, with cyclopentene only the cyclopropane derivative is formed. Copper (I) triflate-olefin complexes can be used in place of silver slats to generate the vinyl cation 2, whereby cyclobutenes 7 are formed preferably. - In contrast to vinyl bromide 1, 1-(4-methoxyphenyl)-2-methyl-1-propenyl triflate (5) reacts with cyclopentene, cyclohexene, cyloheptene, (Z)- and (E)-cyclooctene to give mostly the corresponding cyclopropane derivatives 10. The stereoisomeric cyclopropyl compounds 19 are obtained from (Z)- and (E)-2-butene. - The mechanisms of silver-catalysed and silver-free cycloaddition reactions are discussed.
    Notes: 1-Brom-1-(4-methoxyphenyl)-2-methyl-1-propen (1) reagiert mit Cyclohexen, Cyclohepten, (Z)-Cycloocten und den Silbersalzen AgBF4 bzw. AgSbF6 über das Vinylkation 2 unter Cycloaddition überwiegend zu den Cyclobutenen 7b-d. Mit (Z)- und (E)-2- Buten wird das Cyclobuten 8 erhalten. Bei der Umsetzung von 1 unter den gleichen Bedingungen entsteht mit Cyclopenten das Cyclopropanderivat 10a, mit (Z)-Cycloocten entsteht neben dem Cyclobutenderivat 7d die isomere Cyclopropanverbindung 10d. An Stelle der Silbersalze können auch Kupfer(I)-triflat-Olefin-Komplexe zur Erzeugung des Vinylkations 2 verwendet werden, wobei ebenfalls bevorzugt die Cyclobutene 7 erhalten werden. - Im Gegensatz zum Vinylbromid 1 reagiert das 1-(4-Methoxyphenyl)-2-methyl-1-propenyl-triflat (5) mit Cyclopenten, Cyclohexen, Cyclohepten und (Z)- bzw. (E)-Cycloocten überwiegend zu den entsprechenden Cyclopropanderivaten 10. Mit (Z)- und (E)-2-Buten werden die stereoisomeren Cyclopropylverbindungen 19 erhalten. - Die Mechanismen der silbersalzkatalysierten und silberfreien Cycloadditionsreaktionen werden diskutiert.
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    Masthead (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985) 
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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.19851180801
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    Versuche zur Darstellung von Endiazeniumsalzen (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3011-3019 
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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: Experiments to Form Enediazenium Salts(2-Alkoxyvinyl)diazenium salts 9 and 14 are obtained by O-alkylation of glyoxal- (4) and methylglyoxal monodimethylhydrazone (13), resp., with alkyl trifluoromethanesulfonates. Bromination of N-(trimethylsilyl)enehydrazines 16 and 18 in pentane leads to the formation of solid, hydrophilic substances, for which the structures of enediazenium salts 19, α-bromohydrazones 20, or ammonium salts 21 are discussed. These compounds react with nucleophiles (alcohols, amines, thiols, and indole) to give hydrazones 24a-i substituted at C-2.
    Notes: Glyoxal- (4) und Methylglyoxal-monodimethylhydrazon (13) werden durch Trifluormethansulfonsäure-alkylester am Sauerstoff zu (Alkoxyvinyl)diazeniumsalzen 9 bzw. 14 alkyliert. N-Silylierte Enhydrazine 16 und 18ergeben mit Brom in Pentan feste, hydrophile Verbindungen, für die die Strukturen von Endiazeniumsalzen 19 oder α-Bromhydrazonen 20 bzw. Ammoniumsalzen 21 diskutiert werden. Diese Verbindungen addieren Alkohole, Amine, Thiole sowie Indol als Nucleophile am C-Atom 2 unter Bildung der Hydrazone 24a-i.
    Type of Medium: Electronic Resource
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    1,3-Dithienium- und 1,3-Dithioleniumsalze, IV. 1,3-Dithian-2-ylium-tetrafluoroborate - neue Agenzien zur Synthese von 1-Deuterioaldehyden (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3166-3171 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 1,3-Dithienium- and 1,3-Dithiolenium Salts, IV. 1,3-Dithian-2-ylium Tetrafluoroborates - New Agents for the Synthesis of 1-DeuterioaldehydesThe 1,3-dithian-2-ylium tetrafluoroborates 3 react in good yields with sodium borohydride (4) to give the 1,3-dithianes 6 and with sodium borodeuteride (5) to form the precursors 7 of 1-deuterated aldehydes 8. Three 1-deuterioaldehydes 8 are synthesized exemplarily by dethioacetalization of 7.
    Notes: Die 1,3-Dithian-2-ylium-tetrafluoroborate 3 reagieren in guten Ausbeuten mit Natriumborhydrid (4) zu den 1,3-Dithianen 6 und mit -deuterid (5) unter Bildung der Vorläufer 7 von 1-deuterierten Aldehyden 8. Exemplarisch werden drei 1-Deuterioaldehyde 8 durch Dethioacetalisierung von 7 synthetisiert.
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    Kleine Ringe, 54. Cyclopentadienon (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3196-3204 
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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: Small Rings, 54. CyclopentadienoneCyclopentadienone (1) can be generated by photolysis or pyrolysis of several precursors and isolated in an argon matrix. It dimerizes even on thawing of the matrix (38 K). The IR and UV spectroscopic properties of 1 are discussed.
    Notes: Cyclopentadienon (1) kann aus mehreren Vorstufen photolytisch oder pyrolytisch erzeugt und in einer Argonmatrix bei 10 K isoliert werden. Es dimerisiert bereits beim Auftauen der Matrix (38 K). Die IR- und UV-spektroskopischen Eigenschaften von 1 werden beschrieben.
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    URL: http://dx.doi.org/10.1002/cber.19851180819
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    Metallorganische Verbindungen des Iridiums und Rhodiums, XXIII. Chelatphosphan-substituierte Iridaheterocyclen des Typs (chel-P3)[(2)] (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3188-3195 
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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: Organometallic Compounds of Iridium and Rhodium, XXIII. Chelate Phosphane-Substituted Iridaheterocycles of the Form (chel-P3)When treated with chelate phosphanes chel-P3, aryl iridium(I) compounds of the type Ir(CO)[C6H4-nMen-CH3-(2)](PPh3)2 readily undergo PPh3 substitution, CO insertion, and oxidative benzyl C-H addition to give metallaheterocyclic complexes of formula fac-(Chel-P3) 1-4) (C6H4-nMen=C6H4, C6H3Me-(6), C6H2Me2-(4,6); chel-P3=PhP[(CH2)3PPh2]2, MeP[(CH2)3PPh2]2, PhP[(CH2)2PPh2]2, MeC(CH2-PPh2)3). The cyclic iridium(III) species have been investigated by IR, 1H, and 31P NMR spectroscopy as well as by a single crystal X-ray diffraction analysis of fac-[PhP(CH2CH2-CH2PPh2)2] 1a).
    Notes: Aryliridium(I)- Verbindungen des Typs Ir(CO)[C6H4-nMen-CH3-(2)](PPh3)2 reagieren mit Chelatphosphanen chel-P3 unter PPh3-Substitution, CO-Insertion und oxidativer Benzyl C - H-Addition spontan zu metallaheterocyclischen Iridaindanon-Spezies der Formel fac-(chel-P3)1 - 4) (C6H4-nMen=C6H4, C6H3Me-(6), C6H2Me2-(4, 6); chel-P3=PhP[(CH2)3PPh2]2, MeP[(CH2)3PPh2]2, PhP[(CH2)2PPh2]2 MeC(CH2PPh2)3). Die cyclischen Iridium(III)-Verbindungen wurden spektroskopisch (IR, 1H- und 31P-NMR) sowie röntgenographisch (fac-[PhP(CH2CH2CH2PPh2)2]-, 1 a) untersucht.
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    URL: http://dx.doi.org/10.1002/cber.19851180818
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    Synthesen substituierter elektronenreicher N-Sulfonyl-1-azabutadiene (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3217-3226 
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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 Substituted Electron-rich N-Sulfonyl-1-azabutadienesThe syntheses of alkylthio- und arylthio-substituted electron-rich N-sulfonyl-1-azabutadienes 3a - e, 5a - d, and 10a - c, of dialkylamino-substituted N-sulfonyl-1-azabutadienes 6a - g, and the sulfoxide 11 are described.
    Notes: Es wird über die Synthesen der alkylthio- bzw. arythiosubstituierten elektronenreichen N-Sulfonyl-1-azabutadiene 3a - e sowie 5a - d und 10a - c, über die dialkylaminosubstituierten N-Sulfonyl-1-azabutadiene 6a - g und das Sulfoxid 11 berichtet.
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    URL: http://dx.doi.org/10.1002/cber.19851180821
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    (tert-Butylimino)[tert-butyl(trimethylsilyl)amino]boran, ein Aminoiminoboran, und seine Reaktionen (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3205-3216 
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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: (tert-Butylimino)[tert-butyl(trimethylsilyl)amino]borane, an Aminoiminoborane, and its ReactionsThe title compound (1b) was prepared by gas-phase elimination of FSiMe3 from the corresponding diaminoborane as a distillable liquid, storable at -30°C, dimerizing at room temperature. Additions to the more unsaturated BN-bond are typical for 1b. Protic reagents are added to give the aminoboranes 3a - c. The aminoboranes 3d - h are formed by ethylo-, azido-, or chloroboration or by azidosilation of 1b, respectively. The chloroboration can be followed by the novel formation of the diazadiboretidines 2e - g. Iminoboranes give a ring closure with 1b, the diazadiboretidines 2b,h being formed. The addition of the CO-bond of aldehydes to 1b yields the oxazaboretidines 4a - c. The [2 + 3]-cycloaddition products 5a,b are isolated by the reaction of 1b with azide- or nitrone-type 1,3-dipolar systems. The borane 1b behaves as a dienophile towards cyclopentadiene with the bicyclic molecule 6 as the product. By X-ray analysis, the central ring-unit of 2f turns out to be a BNBN-rhombus with the acute angles at the N-atoms.
    Notes: Die Titelverbindung (1b) erhält man als destillierbare, bei -30°C lagerfähige, bei Raumtemperatur dimerisierende Flüssigkeit durch Gasphaseneliminierung von FSiMe3 aus dem entsprechenden Diaminoboran. Typisch für 1b sind Additionen an die stärker ungesättigte BN-Bindung. Protonenaktive Stoffe addieren sich zu den Aminoboranen 3a - c. Durch Ethylo-, Azido- oder Chloroborierung sowie durch Azidosilierung erhält man die Aminoborane 3d - h. Die Chloroborierung kann mit einer neuartigen Bildung der Diazadiboretidine 2e - g einhergehen. Iminoborane addieren sich an 1b zu den Diazadiboretidinen 2b,h. Die Addition der CO-Bindung von Aldehyden führt zu den Oxazaboretidinen 4a - c. 1,3-Dipolare Verbindungen vom Azid- bzw. Nitrontyp ergeben die Fünfring-Verbindungen 5a,b. Mit Cyclopentadien reagiert 1b als Dienophil zum Bicyclus 6. Für die Verbindung 2f ergibt sich als zentrale Baueinheit röntgenographisch eine BNBN-Raute mit spitzen Winkeln an den N-Atomen.
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    Zur Kenntnis der Cycloaddukte aus 3-Imino-3H-1,2,4-dithiazolen und Nitrilen: Herstellungsbedingungen und Molekülstruktur (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3241-3247 
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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: Cycloadducts from 3-Imino-3H-1,2,4-dithiazoles and Nitriles: Conditions of Preparation and StructureA series of (thiocarbamoylimino)-1,2,4-thiadiazolines (2) was prepared by ring-opening cycloaddition from some imino-1,2,4-dithiazoles (1) and different nitriles. The structure of 2j was determined by X-ray analysis and compared with an isomeric thiadiazolidine (3).
    Notes: Eine Reihe von (Thiocarbamoylimino)-1,2,4-thiadiazolinen (2) wurde durch ringöffnende Cycloaddition aus einigen Imino-1,2,4-dithiazolen (1) und verschiedenen Nitrilen hergestellt. Von 2j wurde eine Röntgenstrukturanalyse angefertigt und mit der eines isomeren Thiadiazolidins (3) verglichen.
    Additional Material: 2 Ill.
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    Hochdruckversuche, XIII. Die Reaktion von tert-Butylisonitril und von Toluol mit Bicyclo[2.2.1]hepten unter Hochdruckbedingungen (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3275-3286 
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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: High Pressure Experiments, XIII. Reaction of tert-Butyl Isonitrile and of Toluene with Bicyclo[2.2.1]heptene (Norbornene) at High PressureAt pressure of about 10 kbar tert-butyl isonitrile reacts with bicyclo[2.2.1]heptene (norbornene) in low yield to give many products of which addition compounds 2 - 11 were identified. With pure toluene exo-2-benzylbicyclo[2.2.1]heptane (10) was found. With oxygen containing toluene also exo-2,3-epoxybicyclo[2.2.1]heptane (2) was isolated. The structure of methanopyrroloindole 6 is confirmed by an X-ray structure analysis.
    Notes: Unter einem Druck von etwa 10 kbar verbindet sich tert-Butylisonitril mit Bicyclo-[2.2.1]hepten (Norbornen) in geringer Ausbeute zu mehreren Produkten, von denen die Verbindungen 2 - 11 aufgeklärt werden konnten. Mit reinem Toluol entsteht in 41proz. Ausbeute exo-2-Benzylbicyclo[2.2.1]heptan (10). Mit sauerstoffhaltigem Toluol wird auch exo-2,3-Epoxybicyclo[2.2.1]heptan (2) erhalten. Von Methanopyrroloindol 6 wurde eine Röntgenstrukturanalyse durchgeführt.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19851180827
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    Synthese mittlerer und großer Ringe, XI. Bicyclo[n.2.2]alkene aus überbrückten Oxepinen - Synthese von 3,6-Pentanooxepin-4,5-dicarbonsäure-dimethylester und 6,9-Dihydro[5]paracyclophan-7,8-dicarbonsäure-dimethylester (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3287-3298 
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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 of Medium and Large Rings, XI. Bicyclo[n.2.2]alkenes from Bridged Oxepins - Synthesis of Dimethyl 3,6-Pentanooxepin-4,5-dicarboxylate and Dimethyl 6,9-Dihydro[5]paracyclophane-7,8-dicarboxylateA new approach to bicyclo[5.2.2]undec(adi)enes and bicyclo[6.2.2]dodecene derivatives, starting from cycloheptanone and cyclooctanone is described. Key steps of this synthesis are the conversion of 3,4-pentano- and -hexanofuran to the β,β′-bridged oxepins 2 and the transannular addition of bromine to 2. The dibromides 3a and 3b can be debrominated to give 3c and 3d in high yield.
    Notes: Ein neuer Zugang zu Bicyclo[5.2.2]undec(adi)enen und Bicyclo[6.2.2]dodecen-Derivaten, ausgehend von Cycloheptanon und Cyclooctanon, wird beschrieben. Schlüsselschritte dieser Synthese sind die Überführung von 3,4-Pentano- und -Hexanofuran in die β,β′-überbrückten Oxepine 2 und eine transannulare Addition von Brom an 2. Die Dibromide 3a und 3b lassen sich in hohen Ausbeuten zu 3c und 3d entbromieren.
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    Kohlenhydrat-Modelle, I. Kinetische und thermodynamische Effekte bei Acetalisierungsreaktionen enantiomerenreiner Thiolactole (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3299-3310 
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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: Carbohydrate-Model Compounds, I. Kinetic and Thermodynamic Effects in Acetal Formation of Enantiomerically Pure ThiolactolsThe synthesis of the enantiomerically pure thiolactol 1 is described. Depending on reaction conditions either (R)-2 or (S)-2 reacts with preference in acetal formation with racemic 1-phenylethanol (rac-2).
    Notes: Die Herstellung des enantiomerenreinen Thiolactols 1 wird beschrieben. Bei der Acetalisierung mit racemischem 1-Phenylethanol (rac-2) reagiert je nach Wahl der Reaktionsbedingungen entweder (R)-2 oder (S)-2 bevorzugt.
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    URL: http://dx.doi.org/10.1002/cber.19851180829
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    Aliphatische Flüssigkristalle, 2. Einige nematische Derivate des all-trans-Perhydrophenanthrens (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3332-3349 
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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, 2. Some Nematic Derivatives of all-trans-PerhydrophenanthreneA stereoselective synthesis of the all-trans-7-alkylperhydro-2-phenanthrenols 15a - f in 11 steps and 28 liquid crystalline esters 16 of 15a - f are described, additionally some further derivatives of 7-alkylperhydro-2-phenanthrenol. An X-ray structure analysis of ester 16ec is reported.
    Notes: Die stereoselektive Synthese der all-trans-7-Alkylperhydro-2-phenanthrenole 15a - f in 11 Stufen und 28 flüssigkristalline Ester 16 von 15a - f werden beschrieben, daneben einige weitere Derivate der 7-Alkylperhydro-2-phenanthrenole. Vom Ester 16ec wurde eine Röntgenstrukturanalyse durchgeführt.
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    URL: http://dx.doi.org/10.1002/cber.19851180832
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    Komplexierung von Blei(II) durch Azakronenether und Kryptanden in Methanol (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3408-3412 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Complexation of Lead(II) by Aza Crown Ethers and Cryptands in MethanolThe stability of PbII complexes with the mono- and bicyclic ligands 1 - 5 in methanol was determined by potentiometric titrations using an ion-selective lead(II) electrode. Reaction enthalpies ΔH were measured by calorimetric titrations. Substitution of the protons at the nitrogen atoms of aza crown 1b by the long decyl chains in 1d leads to a great increase in ΔH, whereas the complex stability is scarcely influenced. Benzo anellands (3, 4) reduce the ligand flexibility and cause a decrease in reaction enthalpies. The reaction entropies are nearly unchanged.
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    Cycloaddition of Singlet Oxygen and 4-Phenyl-4H-1,2,4-triazole-3,5-dione to 7-Substituted 1,3,5-Cyclooctatrienes (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3357-3379 
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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: Cycloaddition von Singulettsauerstoff und 4-Phenyl-4H-1,2,4-triazol-3,5-dion mit 7-substituierten 1,3,5-CyclooctatrienenDie Cycloadditionen von 7-substituierten (X; Y) 1,3,5-Cyclooctatrienen 3 (N3; H), 4 (OAc; H), 5 (OEt; OEt), 6 (Me; H) und 7 (iPr; H) mit Singulettsauerstoff (1O2) und 4-Phenyl-4H-1,2,4-triazol-3,5-dion (PTAD) wurden untersucht. Singulettsauerstoff reagierte mit diesen Cyclooctatrienen aus dem bicyclischen Valenzisomeren (Bicyclo[4.2.0]octa-2,4-dien) heraus zu den entsprechenden tricyclischen Endoperoxiden. Bicyclische Endoperoxide, ausgehend von monocyclischen Valenzisomeren (1,3,5-Cyclooctatrien), wurden lediglich bei den alkylsubstituierten Derivaten 6 (Me; H) und 7 (iPr; H) erhalten. Die Cyclcoaddition mit PTAD führte zu den bicyclischen und tricyclischen Urazolen, mit Ausnahme des Acetals 5 (OEt; OEt), welches nur das tricyclische Produkt gab. Das Bromderivat 2 reagierte weder mit 1O2 noch mit PTAD. Kontrollexperimente mit der Stammverbindung zeigten, daß die Cycloadditionsprodukte entsprechend den mono- und bicyclischen Valenzisomerenanteilen des Eduktgemisches erhalten wurden.
    Notes: The cycloaddition of the 7-substituted (X; Y) 1,3,5-cyclooctatrienes 3 (N3; H), 4 (OAc; H), 5 (OEt; OEt), 6 (Me; H), and 7 (iPr; H) with singlet oxygen (1O2) and 4-phenyl-4H-1,2,4-triazole-3,5-dione (PTAD) was investigated. Singlet oxygen gave with all cyclooctatrienes the corresponding tricyclic endoperoxides derived from the bicyclic valence isomers (bicyclo[4.2.0]octa-2,4-dienes). The corresponding bicyclic endoperoxides derived from the monocyclic valence isomers (1,3,5-cyclooctatriene) were only obtained for the alkyl-substituted derivatives 6 (Me; H) and 7 (iPr; H). PTAD cycloaddition led to both the bicyclic and tricyclic urazoles, except with the acetal 5 which gave only tricyclic product. The bromo derivative 2 did not react with 1O2 nor PTAD. Control experiments with the parent cyclooctatriene showed that the cycloaddition products were derived from the “static” amounts of the monocyclic and bicyclic valence isomers in the substrate mixture.
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    Decarboxylierungsprodukt von Hexahydrophthalsäureanhydrid: Struktur und spektroskopische Eigenschaften (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3413-3418 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Product of Decarboxylation of Hexahydrophthalic Anhydride: Structure and Spectroscopic PropertiesThe decarboxylation of some dicarboxylic anhydrides by catalytic influence of tertiary amines occurs at surprisingly low temperature (T≥80°C). The product 12, formed from two molecules of hexahydrophthalic anhydride 6 with loss of one molecule of carbon dioxide, has been isolated and characterized by spectroscopic investigations and X-ray structure analysis.
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    [2 + n]-Cycloadditionen des [Bis(trimethylsilyl)methylen]-[(trimethylsilyl)ethinyl]phosphans (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3419-3423 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: [2 + n]-Cycloadditions of [Bis(trimethylsilyl)methylene][(trimethylsilyl)ethynyl]phosphane[2 + n]-Cycloadditions of phosphaalkene 1 with sulfur, selenium, 2,3-dimethylbutadiene, diphenyldiazomethane, and trimethylsilyl azide leading to 2, 3, 11, 14, and 15 are reported.
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    Zur Lewis-Acidität von Nickel(0), II. Methylentriorganylphosphoran-Komplexe von Nickel(0) (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 298-312 
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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 Lewis Acidity of Nickel(0), II. Methylenetriorganylphosphorane Complexes of Nickel(0)Methylenetriorganylphosphoranes R3P = CH2 (R = CH3, C6H5) react with Ni(CDT) and Ni(C2H4)3 to form the (methylenetriorganylphosphorane)(alkene)nickel(0) complexes (R3PCH2)Ni(CDT) (R = CH3, 2) and (R3PCH2)Ni(C2H4)2) (R = CH3, C6H5, 4, 5). On treatment with CO the ethene complexes give the known carbonyl complexes (R3PCH2)Ni(CO)3 (R = CH3, C6H5, 9, 10) in pure form. 2 and 4 decompose at room temperature to give Me3PNi(CDT) and Me3PNi(C2H4)2; cyclopropane is produced in the presence of ethene.  -  The stability of the CH2—Ni0 bond in the methylenetriorganylphosphorane complexes falls in the series Ni(CO)3 〉 Ni(C2H4)2 〉 Ni(CDT), corresponding to declining Lewis acidity of the nickel atom. 13C NMR evidence indicates that in the same sequence the P—CH2 bond also becomes weakened. The thermally induced elimination of methylene shows that the nickel bonded methylene group has appreciable carbenoid character.
    Notes: Methylentriorganylphosphorane R3P = CH2 (R = CH3, C6H5) reagieren mit Ni(CDT) und Ni(C2H4)3 zu den (Methylentriorganylphosphoran)(alken)nickel(0)-Komplexen (R3PCH2) Ni(CDT) (R = CH3, 2) und (R3PCH2)Ni(C2H4)2(R = CH3, C6H5, 4, 5). Die Ethen-Komplexe ergeben mit CO die bereits bekannten Carbonyl-Komplexe (R3PCH2)Ni(CO)3(R = CH3, C6H5, 9, 10) in reiner Form. 2 und 4 gehen bei Raumtemperatur in Me3PNi(CDT) und Me3PNi(C2H4)2 über, wobei sich in Gegenwart von Ethen Cyclopropan bildet.  -  Die Stabilität der CH2—Ni0-Bindung in den Methylentriorganylphosphoran-Komplexen verringert sich mit der in der Reihe Ni(CO)3 〉 Ni(C2H4)2 〉 Ni(CDT) abfallenden Lewis-Acidität des Nickels. Aus den 13C-NMR-Spektren ist ableitbar, daß sich in gleicher Sequenz auch die P—CH2-Bindungsordnung vermindert. Die thermisch induzierte Methylen-Abspaltung läßt auf einen carbenoiden Charakter der an Nickel(0) gebundenen Methylengruppen schließen.
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    Zur Lewis-Acidität von Nickel(0), III. Alkalimetall-hydridotrialkylaluminat-Komplexe von Ni(CDT) (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 313-322 
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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 Lewis Acidity of Nickel(0), III. Alkali Metal Hydridotrialkylaluminate Complexes of Ni(CDT)Ni(CDT) reacts with hydridotrialkylaluminates of the alkali metals in ether/THF or ether/amine mixtures at temperatures below -50°C to form the temperature-sensitive compounds [MA(n-Donor)n]+[R3Al—H—Ni(CDT)]- (1-7) (MA = Li, Na; R = Me, Et, iBu). An Al—H—Ni three-centre bond is present in these complexes. On the basis of NMR data, the strength of the hydridoaluminate-nickel bond and the charge on nickel, caused by the hydridoaluminate residue, are compared with the corresponding characteristics of other ligand-Ni(CDT) complexes in which donor-acceptor σ-bonds are present.
    Notes: Ni(CDT)Abkürzungen: CDT = trans, trans, trans-1,5,9-Cyclododecatrien, COD = 1,5-Cyclooctadien, MA+ (solvatisiertes) Alkalimetall-Ion, PMDTA = N,N,N′,N″N″-Pentamethyldiethylentriamin, TMEDA = N,N,N′,N′-Tetramethylethylendiamin. reagiert mit Alkalimetall-hydridotrialkylaluminaten in Ether/THF-oder Ether/Amin-Mischungen als Lösungsmittel unterhalb von -50°C zu den thermisch labilen Verbindungen [MA(n-Donor)n]+[R3Al—H—Ni(CDT)]- (1-7) (MA = Li, Na; R = Me, Et, iBu). In diesen Komplexen liegt eine Al—H—Ni-Mehrzentrenbindung vor. Anhand NMR-spektroskopischer Daten lassen sich die Stärke der Hydridoaluminat-Nickel-Bindung und die Beladung des Nickels durch den Hydridoaluminat-Rest mit den Bindungsverhältnissen in anderen Ligand-Ni(CDT)-Komplexen mit Donor-Akzeptor-σ-Bindungen vergleichen.
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    Neue Reagenzien, XXIX. Synthese, Stabilität und präparative Anwendung von (Triphenylplumbyl)methyllithium (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 370-379 
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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: New Reagents, XXIX. Synthesis, Stability, and Preparative Applications of (Triphenylplumbyl)methyllithium(Triphenylplumbyl)methyllithium (2), obtained from well accessible starting compounds by iodine-Li- or plumbyl-Li exchange, is applied as a reagent for the introduction of the (triphenylplumbyl)methyl group into alkyl halides, aldehydes, ketones, oxiranes, and organoelement halides.
    Notes: (Triphenylplumbyl)methyllithium (2), durch Iod-Li- oder Plumbyl-Li-Austausch mit Phenyllithium in Tetrahydrofuran aus gut zugänglichen Ausgangssubstanzen erhältlich, wird als Reagenz zur Einführung der (Triphenylplumbyl)methyl-Gruppe in Alkylhalogenide, Aldehyde, Ketone, Oxirane und Organoelementhalogenide angewandt.
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    Notiz zur Reaktion des 3-Iminophenoxazins mit Ammoniak und Aminen (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 397-400 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Note on the Reaction of 3-Iminophenoxazine with Ammonia and AminesPhenazines and phenoxazines are formed in the reaction of 3-iminophenoxazine with amines.
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    Neue Reagenzien, XXXI. Synthese von (Iodmethyl)- und (Diiodmethyl)element-Verbindungen der Elemente Si, Ge, Sn, Pb (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 391-396 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: New Reagents, XXXI. Synthesis of (Iodomethyl)-and (Diiodomethyl)element Compounds of the Elements Si, Ge, Sn, PbVia Li—CH2—Hal or Li—CHHal2 (Hal = I, Br), respectively, the monohalides Ph3El—CH2—I (El = Si, Ge, Pb) and Ph3 Ge—CH2—Br have been obtained (49-74%) as well as the dihalides Ph3El—CHI2 (El = Si, Ge, Sn; 49-69%), Ph3Pb—CHI2 (9%), and Ph3Ge—CHBr2 (78%). These compounds are favourable starting materials for corresponding monolithium compounds. Some of them have found synthetic applications.
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    Kleine Ringe, 50. Ungewöhnliche Dimerisierung von Tri-tert-bytylcyclobutadien (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 409-412 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Small Rings, 50. Unusual Dimerization of Tri-tert-butylcyclobutadieneThe dimerization of tri-tert-butylcyclobutadiene (2) does not lead to syn-dimer 4 but  -  as shown by a X-ray structure determination  -  via a two-step process to the unexpected anti-configurated dimer 5.
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    Diazadiene als Steuerliganden in der homogenen Katalyse, IX. Katalytische Cyclotetramerisierung von Propiolsäureestern (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 428-435 
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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: Diazadienes as Controlling Ligands in Homogeneous Catalysis, IX Catalytic Cyclotetramerization of Propynoic EstersPropynoic esters HC≡C—CO2R 2 react at low temperature in cyclohexane in the presence of precatalysts of the type of diazadiene-nickel(0) complexes 3 and 4 or diazadiene-nickel-(η2-alkyne) complexes such as 5b to give exclusively or preponderantly cyclooctatetraene tetracarboxylic esters 7. From 1H and 13C NMR data and by chemical methods a 1,3,6,8-substitution pattern (symmetry C2) is established.
    Notes: Propiolsäureester HC≡C—CO2R 2 lassen sich bei niedriger Temperatur in Cyclohexan an Präkatalysatoren vom Typ der Diazadien-Nickel(0)-Komplexe 3 bzw. 4 oder an Diazadien-Nickel-(η2-Alkin)-Komplexen wie 5b vollständig oder überwiegend zu Cyclooctatetraen-tetracarbon-säureestern 7 umsetzen. Aus 1H- und 13C-NMR-Daten sowie mit chemischen Methoden ergibt sich ein 1,3,6,8-Substitutionsmuster (Symmetrie C2).
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    Palladium- und Platin(II)-Komplexe mit den Anionen von 6-Methyl-1,2,3-oxathiazin-4(3H)-on-2,2-dioxid und N-2-Pyrimidinylsulfanilamid (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 444-449 
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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: Palladium and Platinum(II) Complexes with the Anions of 6-Methyl-1,2,3-oxathiazin-4(3H)-one 2,2-Dioxide and N-2-PyrimidinylsulfanilamideWith the title ligand L = 3 the complexes K2[trans-PtCl2L2] (1) and K2[ML4] (M = Pt,Pd) (2, 4) have been obtained. The anion 5 of sulfadiazine and (nBu3P)(CI)PdCl2Pd(Cl)(PnBu3) give a dinuclear ligand bridged complex 6. The compounds are characterized by their IR and 1H NMR spectra. The structure of 1 was determined by X-ray structure analysis.
    Notes: Mit dem Titelliganden L = 3 werden die Komplexe K2[trans-PtCl2L2] (1) und K2[ML4] (M = Pt, Pd) (2, 4) erhalten. Das Sulfadiazin-Anion (5) bildet mit (nBu3P)(Cl)PdCl2Pd(Cl)(PnBu3) einen zweikernigen ligandverbrückten Komplex 6. Die Verbindungen werden spektroskopisch (IR, 1H-NMR) charakterisiert; die Struktur von 1 wird durch eine Röntgenstrukturanalyse bestimmt.
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    Ein neuer Zugang zu Alkylthio(trifluoracetyl)furanen durch thermische [3 + 2]-Cycloadditionen neuer mesoionischer 1,3-Oxathiol-4-one an Alkine (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 785-795 
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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: A New Entry to Alkylthio(trifluoroacetyl)furans by Way of Thermal [3 + 2]Cycloaddition Reactions of New Mesoionic 1,3-Oxathiol-4-ones to AlkynesAs cyclic carbonyl ylides, the novel 2-alkylthio-5-trifluoroacetyl-1,3-oxathiolylium-4-olates of type 1a-d combine with dimethyl acetylenedicarboxylate across the 2,5-position with formation of non-isolable primary adducts, which release COS to give the furandicarboxylic diesters 3a-d. Methyl propiolate reacts with 1a-c to produce mixtures of the regioisomeric furancarboxylic esters 4a-c and 5a-c, whose main components 4a-c are isolable. On the other hand, the reactions of phenylacetylene, 1-diethylaminopropyne, or (Z)-1-methoxy-1-buten-3-yne with 1a proceed with regiospecific formation of the furan derivatives 6, 7, or 8, respectively. The observed regioselectivities are qualitatively discussed on the basis of MO-perturbation theory.
    Notes: Als cyclische Carbonyl-ylide nehmen die neuen 2-Alkylthio-5-trifluoracetyl-1,3-oxathiolylium-4-olate vom Typ 1a-d in 2,5-Stellung Acetylendicarbonsäure-dimethylester unter Bildung nicht-isolierbarer Primäraddukte auf, die unter COS-Abspaltung Furandicarbonester 3a-d liefern. Mit Propiolsäure-methylester reagiert 1a-c zu Gemischen aus den regioisomeren Furancarbonestern 4a-c und 5a-c, deren Hauptkomponenten 4a-c isolierbar sind. Dagegen vereinigen sich Phenylacetylen, 1-Diethylaminopropin bzw. (Z)-1-Methoxy-1-buten-3-in mit 1a regiospezifisch zu den Furan-Derivaten 6, 7 bzw. 8. Die beobachteten Regioselektivitäten werden qualitativ auf der Basis der MO-Störungstheorie diskutiert.
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    Electron donor-acceptor compounds, XXXVI. Quinones and quinhydrones of the [2.2]- and [3.3]metaparacyclophane series (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 796-813 
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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: Elektron-Donor-Acceptor-Verbindungen, XXXVI Chinone und Chinhydrone der [2.2]- und [3.3]Metaparacyclophan-ReihenDie isomeren Chinhydrone 1 und 2 sowie das Bis(chinon) 6 der [2.2]Metaparacyclophan-Reihe wurden synthetisiert. Vorstufe dieser Verbindungen war das Tetramethoxy[2.2]metaparacyclophan 3, das über 4 und 5 dargestellt wurde. Röntgen-Strukturanalysen von 1, 3 und 6 werden im Hinblick auf die sterische Spannung dieser Moleküle und die Donor-Acceptor-Orientierung in 1 diskutiert. Charge-transfer-Absorptionen von 1 und 2 werden ebenso behandelt wie der Circulardichroismus von 1, das in Enantiomere getrennt werden konnte.  -  Auf analogem Wege wurden die isomeren Chinhydrone 13 und 14 sowie das Bis(chinon) 15 der [3.3]Metaparacyclophan-Reihe dargestellt. Der Unterschied in der sterischen Spannung zwischen den [3.3]- und [2.2]-Metaparacyclophan-Reihen wird auf der Grundlage der Röntgen-Strukturanalyse von 13 diskutiert. Charge-transfer-Absorptionen von 13 und 14 werden angegeben.
    Notes: The isomeric quinhydrones 1 and 2 as well as the bis(quinone) 6 of the [2.2]metaparacyclophane series were synthesized. Precursor of these products was the tetramethoxy[2.2]metaparacyclophane 3 which was prepared via 4 and 5. X-ray structure analyses of 1, 3 and 6 are discussed with regard to the steric strain in these molecules and the donor-acceptor orientation in 1. Charge-transfer absorptions of 1 and 2 are reported as well as circular dichroism of 1 which was separated into enantiomers.  -  Following an analogous route the isomeric quinhydrones 13 and 14 as well as the bis(quinone) 15 of the [3.3]metaparacyclophane series were prepared. The difference in steric strain of the [3.3]- in comparison to the [2.2]metaparacyclophane series is discussed on the basis of an X-ray structure analysis of 13. Charge-transfer absorptions of 13 and 14 are reported.
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    Disproval of claimed unusually stable primary ozonides of 1,4-dichloro-2-butenes (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 845-850 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Beweise gegen postulierte ungewöhnlich stabile Primärozonide von 1,4-Dichlor-2-butenenOzonolysen von cis- und trans-1,4-Dichlor-2-buten (1) in Methanol ergaben ca. äquimolare Anteile an 2-Chlor-1-methoxyethanol (6a) und 2-Chlor-1-methoxyethylhydroperoxid (7a) als Hauptprodukte sowie eine geringe Menge 2,2′-Dichlor-1-hydroxy-1′-methoxydiethylperoxid (8a). Ozonolyse von 1 in [D4]Methanol ergab die entsprechenden deuterierten Produkte 6c-8c. Die postulierte Existenz von ungewöhnlich stabilen Primärozoniden 2 wird widerlegt.
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    Organische Synthesen mit Übergangsmetallkomplexen, 10. Metalltemplate zur Synthese carbocyclischer Vier- und Sechsringe aus Isonitrilen und Carbenkomplexen (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 952-963 
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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: Organic Syntheses with Transition Metal Complexes, 10. Metal Templates for the Syntheses of Carbocyclic Four- and Six-membered Rings from Isonitriles and Carbene ComplexesIsonitriles (R—NC, R = CH3, c-C6H11, tC4H9) react with carbene complexes (CO)5CrC(OCH3)R′ (R′ = CH3, C6H5) to give ketenimine complexes (CO)5Cr(R)N=C=C(OCH3)R′ 2a-f via insertion of the isonitrile into the M=C bond. The complexes 2 are isolated in crystalline form. On warming they dismutate to (CO)6Cr and (CO)4Cr complexes 3a-f of a 1,2-bis(imino)cyclobutane chelate ligand 4. The ligands 4 are generated in a template reaction by a hitherto unknown symmetrical [2 + 2]dimerisation of the ketenimines. 4 and the 1, 2-bis(hydroximino)cyclobutane 5 are obtained free of the metal by disengagement with H2O2/OH- or H2NOH, respectively. 3d, e easily isomerize to give bis(imino)tetrahydronaphthalenes 6d, e by expansion of the carbocyclic four- to the six-membered ring incorporating the phenyl group. Thermolysis of 6 leads to the formation of the 1,2-dihydronaphthaline derivative 7. The latter is also accessible in a one-pot synthesis from the carbene complex and the isonitrile without isolation of the intermediates 2, 3, and 6.
    Notes: Isonitrile (R — NC, R = CH3, c-C6H11, t-C4H9) reagieren mit Carbenkomplexen (CO)5CrC(OCH3)R′ (R′ = CH3, C6H5) unter Insertion der N = C- in die M = C-Bindung zu kristallin isolierbaren Keteniminkomplexen (CO)5Cr(R)N = C = C(OCH3)R′ 2a-f. Letztere sind sehr kondensations-freudig und dismutieren bei Abwesenheit eines Reaktionspartners zu (CO)6Cr und (CO)4Cr-Komplexen 3a-f, die ein 1,2-Bis(imino)cyclobutan 4 als Chelatligand enthalten. 4 bildet sich in einer Templatreaktion unter bisher unbekannter symmetrischer [2 + 2]-Dimerisierung des Keteniminliganden. Metallfreies 4 und ein davon abgeleitetes 1,2-Bis(hydroximino)cyclobutan 5 erhält man durch oxidative Zersetzung von 3 mit H2O2/OH- oder H2NOH. Die Bis(imino)cyclobutan-Komplexe 3d, e isomerisieren beim Erwärmen zu Bis(imino)tetrahydronaphthalin-Komplexen 6d, e durch Ringerweiterung des carbocyclischen Vier- zum Sechsring unter Einbeziehung des Aromaten. Die Thermolyse von 6e oder 6e′ gibt ein metallfreies 1,2-Dihydronaphthalin 7. Dieses kann in einer „Eintopfsynthese“ auch ohne Isolierung der Zwischenstufen 2, 3 und 6 direkt aus dem Carbenkomplex und dem Isonitril erhalten werden.
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    Versuche zur Darstellung eines Alkinyldiazonium-Salzes (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 1008-1021 
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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: Attempts to Prepare an Alkynyldiazonium SaltThe 2-bromo-1-chloroalkanal p-tosylhydrazones 11a, and b react with triethylamine as base to give the azoalkenes 12, of which (1-chloro-2-phenylethenyl)tosyldiazene (12b) is obtained as a crystalline material at room temperature. 12b reacts with SbCl5 at - 30 and - 70°C to form different diazonium salts, which are treated with nucleophiles such as methanol and water. The products obtained (Schemes 3 and 4) indicate the formation of the phenylethynyldiazonium salt 20, which is stable up to - 20°C. 20 adds nucleophiles like methanol or water as well as anisole at the C°C triple bond before releasing nitrogen.
    Notes: Die 2-Brom-1-chloralkanal-p-tosylhydrazone 11a und b reagieren mit Triethylamin als Base zu den Azoalkenen 12, von denen (1-Chlor-2-phenylethenyl)tosyldiazen (12b) als kristalline, bei Raumtemperatur stabile Verbindung erhalten wird. 12b reagiert mit SbCl5 bei - 30 und - 70°C zu verschiedenen Diazoniumsalzen, die mit nucleophilen Reaktionspartnern (Methanol und Wasser) umgesetzt werden. Die dabei erhaltenen Produkte (Schema 3 und 4) deuten auf die Entstehung des Phenylethinyldiazonioum-Salzes 20, das bis etwa - 20°C stabil ist. 20 addiert Nucleophile wie Methanol oder Wasser, aber auch Anisol an die C°C-Dreifachbindung, bevor eine Stickstoffabgabe erfolgt.
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    Magnesium-acetylacetonat, Mg3[MeC(O)CHC(O)Me]6, und Magnesium-(diethoxyphosphinyl)acetonat, Mg3[(EtO)2P(O)CHC(O)Me]6, dreikernige Chelatkomplexe (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3529-3534 
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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: Magnesium Acetylacetonate, Mg3[MeC(O)CHC(O)Me]6, and Magnesium (Diethoxyphosphinyl)acetonate, Mg3[(EtO)2P(O)CHC(O)Me]6- Trinuclear Chelate ComplexesThe title compounds 1 and 2 have been investigated by X-ray structure analysis and found to be trimeric. Each Mg atom is coordinated by six O atoms with a distorted octahedral array. The bridging of the central Mg atom with the terminal ones is achieved by common O atoms of the carbonyl groups. Whereas the preparation of magnesium (diethoxyphosphinyl)acetonate (2) has been reported previously, magnesium acetylacetonate (1) has been obtained for the first time by dehydration of Mg(acac)2(H2O)2.
    Notes: Röntgenuntersuchungen ergaben für die Titelverbindungen 1 und 2 trimere Strukturen. Jedes Mg-Atom ist von sechs O-Atomen verzerrt oktaedrisch koordiniert. Die Verbrückung des zentralen Mg-Atoms mit den endständigen erfolgt durch gemeinsame O-Atome der Car-bonyl-Gruppen. Magnesium-(diethoxyphosphinyl)acetonat (2) wurde nach Literaturangaben hergestellt, die Darstellung von Magnesium-acetylacetonat (1) erfolgte erstmals durch Entwässerung von Mg(acac)2(H2O)2.
    Additional Material: 4 Ill.
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    Photolyse von 9-Azido-10-methyltriptycen. - Dimerisierung eines extrem gespannten Brückenkopfimins durch verschiedene Cycloadditionen (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3535-3550 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Photolysis of 9-Azido-10-methyltriptycene. - Dimerization of a Severely Strained Bridgehead Imine via Distinct Cycloaddition RoutesIrradiation of a cyclohexane solution of the 9-azidotriptycene 1b affords molecular nitrogen and a mixture of products. By means of chromatography a dimer (S2-7), which is yellow in solution, and two colorless dimers (e.g. 3b and 5) of the intermediate bridgehead imine 2b are separated from this mixture. The structures of the photoproducts are elucidated by spectroscopic methods, particularly high field NMR. In addition, the structure 5 is proven by its rapid and quantitative photoisomerization to the colored dimer S2-7 the constitution 7 of which is confirmed by comparison with the anthrone anil 11 and hydrolysis to the (2-aminophenyl)anthrone 9. At room temperature rapid diastereotopomerization of the benzene rings of the 9,10-dihydroanthracene systems of S2-7 occurs via N-inversion (1H, 13C NMR). According to the proton spectrum in the absence of exchange ( - 60 °C), the colored product possesses S2 rather than C2 symmetry. The photoproducts are postulated to be derived from the initially formed azahomotriptycene 2b bearing a formal bridgehead CN double bond. This bridgehead imine first dimerizes to the isomeric 1,4-diradicals 13 and 14 which subsequently cyclize to the intermediate 15 and the [2 + 2] dimer 5, respectively. Photochemical [2 + 2]cycloelimination of 5 affords the dimer S2-7.
    Notes: Durch Bestrahlung des 9-Azidotriptycens 1b in Cyclohexan erhält man neben Stickstoff ein Gemisch, aus dem chromatographisch ein in Lösung gelbes Dimeres (S2-7) und zwei farblose Dimere (3b und 5) des intermediären Brückenkopfimins 2b isoliert werden. Die Strukturen dieser Photoprodukte werden auf spektroskopischem Weg, insbesondere mit Hilfe von Hochfeld-NMR-Spektren, aufgeklärt. Zusätzlich wird die Struktur 5 durch die rasche, quantitative Photoisomerisierung in das farbige Dimere S2-7 gesichert, dessen Konstitution 7 durch Vergleich mit dem Anthronanil 11 und Hydrolyse zum (2-Aminophenyl)anthron 9 bewiesen wird. Bei Raumtemperatur tritt rasche Diastereotopomerisierung der Benzolringe der 9,10-Dihydroanthracen-Systeme von S2-7 durch N-Inversion ein (1H-, 13C-NMR). Aufgrund des 1H-NMR-Spektrums bei Abwesenheit von raschem Austausch ( - 60°C) besitzt das farbige Produkt S2- und nicht C2-Symmetrie. Es wird angenommen, daß zunächst das Azahomotriptycen 2b mit einer formalen Brückenkopf-CN-Doppelbindung entsteht, das zu den rotationsisomeren 1,4-Diradikalen 13 und 14 dimerisiert, die zur Zwischenstufe 15 bzw. dem [2 + 2]-Dimeren 5 cyclisieren. Photochemische [2 + 2]-Cycloeliminierung von 5 ergibt das Dimere S2-7.
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    Übergangsmetallkomplexe instabiler Ylide, VII. Synthese und Reaktivität von als Vertreter eines Ylid-Chelatkomplexes mit exocyclischer C =C-Doppelbindung (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3560-3569 
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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 Complexes of Instable Ylides, VII. Synthesis and Reactivity of as an Example of an Ylide Chelate Complex Containing an Exocyclic C =C Double BondThe sulfur ylide complex (CO)5Cr[CH2S(O)Me2] reacts with 1,1-bis(diphenylphosphino)-ethene (1) to yield the five-membered metalla-heterocycle 2 with a reactive exocyclic C =C double bond. To this double bond carbon-, hydrogen-, phosphorus-, and sulfur nucleophiles are easily added.
    Notes: Der Schwefelylidkomplex (CO)5Cr[CH2S(O)Me2] reagiert mit 1,1-Bis(diphenylphosphino)-ethen (1) zu dem fünfgliedrigen Metallacyclus 2, der eine reaktive exocyclische C =C-Doppelbindung aufweist. An diese werden Nucleophile mit C, H, P und S als Donoratomen glatt addiert.
    Additional Material: 1 Tab.
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  • 83
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    Untersuchungen am 6-Deuterio-1,2,3,5-tetramethyl-4-methylen-endo- und -exo-6-(trideuteriomethyl)bicyclo-[3.1.0]hex-2-en über den Mechanismus der Singulett-angeregten Photo-Isomerisierung des Homofulven-Systems (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3551-3559 
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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: An Investigation of 6-Deuterio-1,2,3,5-tetramethyl-4-methylene-endo- and -exo-6-(trideuteriomethyl)bicyclo[3.1.0]hex-2-ene on the Mechanism of the Singlet Excited Photo-Isomerization of the Homofulvene SystemSyntheses of 6-deuterio-1,2,3,5-tetramethyl-4-methylene-endo- and -exo-6-(trideuteriomethyl)bicyclo[3.1.0]hex-2-ene ([endo-6-CD3, 6-D]-1 and [exo-6-CD3, 6-D]-1) are reported. Following excitation to the S1-state both compounds isomerize to 6-deuterio-1,2,3,4-tetramethyl-5-methylene-6-(trideuteriomethyl)-1,3-cyclohexadiene ([6-CD3, 6-D]-2). The positions of the labelled atoms in 2 are discussed with respect to the mechanism of the photoisomerization 1 → 2.
    Notes: Die Synthesen von 6-Deuterio-1,2,3,5-tetramethyl-4-methylen-endo- und -exo-6-(trideuteriomethyl)bicyclo[3.1.0]hex-2-en ([endo-6-CD3, 6-D]-1 und [exo-6-CD3, 6-D]-1) werden beschrieben. Beide Verbindungen werden nach Anregung in den S1-Zustand zum 6-Deuterio-1,2,3,4-tetramethyl-5-methylen-6-(trideuteriomethyl)-1,3-cyclohexadien ([6-CD3, 6-D]-2) isomerisiert. Aus den Positionen der markierten Atome im Produkt 2 werden Folgerungen über den Mechanismus der Photo-Isomerisierung 1 → 2 abgeleitet.
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    Masthead (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985) 
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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.19851180401
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    Synthesen mit aliphatischen Dialdehyden, XXXIX. Über die Konformation trinuclearer [2.2.2]Heptamethindiium-Cyaninfarbstoffe mit Indolin-Endgruppen (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 1295-1303 
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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 with Aliphatic Dialdehydes, XXXIX. The Conformation of Trinuclear [2.2.2]Heptamethinediium Cyanine Dyes with Indoline End GroupsAccording to ESR and ESCA spectroscopic measurements as well as X-ray analyses the [2.2.2]-heptamethinediium cyanine dyes 1 and 2 exist in the crystalline state and probably in solution as vinylogous amidinium ions (γ-substituted pentamethine cyanine or dicarbocyanine dyes) 1b and 2a.
    Notes: Nach ESR- und ESCA-spektroskopischen sowie röntgenographischen Befunden liegen die [2.2.2] Heptamethindiium-Cyaninfarbstoffe 1 und 2 in kristalliner Form und wahrscheinlich auch in Lösung nicht - wie bislang angenommen - als methinyloge Guanidinium-Ionen 1a und 2a vor, sondern als vinyloge Amidinium-Ionen (γ-substituierte Pentamethincyanin oder Dicarbocyaninfarbstoffe (1b und 2b.
    Additional Material: 2 Ill.
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  • 86
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    Zum Einfluß sterischer Effekte auf die Selektivität radikalischer CC-Verknüpfung (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 1345-1351 
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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 Influence of Steric Effects on the Selectivity of Radical CC Bond Formation ReactionsBulky substituents R1 and R2 at radical 5 decrease the rate of addition to diethyl fumarate to a larger extent than to methyl acrylate (Table 1). The comparison with H-abstraction, which is only slightly influenced by steric effects, shows that 5e (R2 = t-C4H9) reacts at least 235 times slower with diethyl fumarate than 5a (R2 = CH3) (Table 2). Therefore, the stereoselectivity of cyclic radicals 1 (n = 1, 2) increases if the CC bond formation reaction is carried out with diethyl fumarate instead of methyl acrylate.
    Notes: Sperrige Substituenten R1 und R2 am Radikal 5 verringern die Additionsgeschwindigkeit an Fumarsäure-diethylester stärker als die Additionsgeschwindigkeit an Acrylsäure-methylester (s. Tab. 1). Der Vergleich mit dem von sterischen Effekten nur wenig beeinflußten H-Einfang zeigt, daß 5e (R2 = t-C4H9) mindestens 235mal langsamer mit Fumarsäure-diethylester reagiert als 5a (R2 = CH3) (s. Tab. 2). Deswegen steigt die Stereoselektivität der cyclischen Radikale 1 (n = 1,2) um den Faktor 5-7, wenn bei der CC-Verknüpfungsreaktion Fumarsäureester anstelle von Acrylsäureester eingesetzt wird.
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    URL: http://dx.doi.org/10.1002/cber.19851180406
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    d1- und d3-selektive Umsetzungen von schwefelsubstituierten Allyl-Titan-Derivaten mit Aldehyden und Ketonen (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 1329-1344 
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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: d1- and d3-Selective Reactions of Sulfur-substituted Allylic Titanium Derivatives with Aldehydes and KetonesAs previously reported, double deprotonation of allylmercaptane with butyllithium produces the moderately to poorly d3-selective dilithium derivative 1a of thioacrolein (or 1-thiabutadiene). Addition of an equimolar amount of chlortriisopropoxytitanium generates a reagent 1c, which combines with aldehydes and ketones almost exclusively in the γ-position (d3-reactivity, products 2, Table 1, 18 examples). The 2-methyl analogue 4b exhibits a similar d3-selectivity, with somewhat lower chemical yields (products 5, Table 2, 7 examples). In contrast to the dianion derivatives, methyl- and phenyl-allyllithium combine with chlorotriisopropoxytitanium to give reagents (6a, 6b) which add to the same electrophiles practically only in the α-RS-position (d1-reactivity, products 7 and 8, Table 3, 12 examples). Possible conversions of the selectively produced α- and γ-adducts to vinyloxiranes, to γ-hydroxy- and to ε-keto aldehyde derivatives are discussed (Scheme 1). Some examples of Hg(II)-assisted alcoholyses (CH3OH, C2H5OH) of γ-adducts 2 to 2-alkoxytetrahydrofurans (9, 10) are described (Scheme 2, Table 4). „Titanation“ of the Li derivatives not only causes high regioselectivity, but also excellent chemical selectivity of the nucleophilic reagents: they preferentially add to aldehydes vs. ketones and are compatible with other functional groups, such as CN, NO2, I, in the substrate.
    Notes: Das durch doppelte Deprotonierung von Allymercaptan erzeugte Dilithium-Derivat 1a des Thioacrolein- (oder 1-Thiabutadien-)Dianions wird durch Zusatz einer äquimolaren Menge Chlortriisopropoxytitan zu einem Reagenz 1c, das sich mit Aldehyden und Ketonen praktisch ausschließlich in γ-Stellung zum Schwefel vereinigt (d3-Reaktivität, Produkte 2, Tab. 1, 18 Beispiele). Dasselbe gilt für das 2-Methyl-Analoge 4b, welches - in etwas schlechterer Ausbeute - zu über 90% bevorzugt in γ-Stellung reagiert (Produkte 5, Tab. 2, 7 Beispiele). Im Gegensatz zu den Dianionderivaten (1c, 4b) reagieren die Mono-Anionderivate (6a, 6b), die man beim Versetzen von lithiierten Methyl- oder Phenyl-allylsulfid mit Chlortriisopropoxytitan erhält, mit denselben Elektrophilen praktisch vollständig selektiv in α-Stellung zur RS-Gruppe (d1-Reaktivität, Produkte 7 und 8, Tab. 3, 12 Beispiele). Die Umwandlung der selektiv zugänglichen α- und γ-Addukte in Vinyloxirane, γ-Hydroxy- und ε-Ketoaldehyd-Derivate wird diskutiert (Schema 1), und es werden einige Beispiele für die durch Quecksilber(II)-chlorid assistierte Alkoholyse (CH3OH, C2H5OH) von γ-Addukten 2 zu 2-Alkoxytetrahydrofuranen (9, 10) beschrieben (Schema 2, Tab. 4). Die „Titanierung“ der Li-Derivate führt nicht nur zu hoher Regioselektivität, sondern auch zu der für Organotitanverbindungen typischen hohen chemische Selektivität (Aldehyd vs. Keton; Addition an Aldehyd- oder Ketocarbonylgruppe in Gegenwart von Cyan-, Nitro- oder Iodsubstituenten).
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    Niederkoordinierte Phosphorverbindungen, 30. 1-Chlor-2-phenyl-2-(trimethylsilyl)-1-phosphaethen als Synthese-baustein neuer Phosphaalkene (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 1352-1370 
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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: Low Coordinated Phosphorus Compounds, 30. 1-Chloro-2-phenyl-2-(trimethylsilyl)-1-phosphaethene as a Structural Part for New PhosphaalkenesNew phosphorus-substituted phosphaalkenes are synthesized via a reaction of 1-chloro-2-phenyl-2-(trimethylsilyl)-1-phosphaethene (1) with alcohols, amines, amides, phosphanes, and organometallic reagents. Their structures are well documented by NMR data and in the cases of compounds 3a, 5a and 13 also by an X-ray analysis. Properties and some reactions of the new compounds are given.
    Notes: Durch Umsetzung von 1-Chlor-2-phenyl-2-(trimethylsilyl)-1-phosphaethen (1) mit Alkoholen, Aminen, Amiden, Phosphanen und metallorganischen Reagenzien werden neue, am Phosphor substituierte Phosphaalkene erhalten. Ihre Strukturen werden durch NMR-spektroskopische Daten, im Fall der Verbindungen 3a, 5a und 13 auch durch Röntgenbeugungsanalyse belegt. Eigenschaften und einige Reaktionen der neuen Stoffe werden mitgeteilt.
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    Umsetzung organischer Thiocyanate, Selenocyanate und Cyanate mit Malonylchlorid (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 1371-1382 
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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: Reaction of Organic Thiocyanates, Selenocyanates, and Cyanates with Malonyl ChlorideOrganic thiocyanates and selenocyanates react with malonyl chloride to form the pyrano-oxazinediones 1a, b and 2 a, b. Compound 4 is obtained in the case of phenacyl thiocyanate. With the exception of compound 6, nucleophilic substitution of the bromine atom in compound 1 a is not possible. Excess n-propylamine leads to 7, while reaction in acidic medium gives 5. The reaction product of malonyl chloride and aromatic cyanates is strongly dependent on the reaction conditions. At temperatures up to + 20°C, β-lactams 8a - g and hydrolysis products 9 a - e, respectively, are formed. At 30 - 70°C substances 11a, d - f, at 60 - 90°C cyclization products 10a, d - g, and at temperatures of approx. 120°C decarboxylation products 12a, b, d are formed. An X-ray structural analysis is made of 9b.
    Notes: Organische Thio- und Selenocyanate reagieren mit Malonylchlorid zu den Pyrano-oxazindionen 1a, b und 2a, b; im Falle von Phenacylthiocyanat entsteht 4. Nucleophile Substitution des Bromatoms in 1a ist außer zu Verbindung 6 nicht möglich, ein Überschuß an n-Propylamin führt zu 7, während Umsetzung in saurem Medium 5 ergibt. Das Reaktionsprodukt von Malonylchlorid und aromatischen Cyanaten ist stark abhängig von den Reaktionsbedingungen - bei Temperaturen bis + 20°C entstehen die β-Lactame 8a-g bzw. die Hydrolyseprodukte 9a-e, bei 30 - 70°C die Substanzen 11a,d - f, bei 60 - 90°C die Cyclisierungsprodukte 10a, d - g und bei Temperaturen von ca. 120°C die Decarboxylierungsprodukte 12a, b, d. Von 9b wird eine Röntgenstruktur-analyse durchgeführt.
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    Chalkogen-Addukte des Bis(di-tert-butylphosphino)schwefeldiimids - Festkörperstruktur von Bis[di-tert-butyl(thiophosphinyl)]- und Bis[di-tert-butyl(selenophosphinyl)]schwefeldiimid (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 1476-1484 
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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: Adducts of Chalcogens with Bis(di-tert-butylphosphino)sulfur Diimide - Solid State Structures of Bis[di-tert-butyl(thiophosphinyl)]- and Bis[di-tert-butyl(selenophosphinyl)]sulfur DiimideBis(di-tert-butylphosphino)sulfur diimide, S(N — PtBu2)2 (1), adds sulfur and selenium at both phosphorus atoms to give the new chalcophosphinyl-substituted sulfur diimides S[N — P(Y)tBu2]2 (Y = S (2a), Se (2b)). According to the single-crystal X-ray structure analyses, 2a and 2b are present in the unsymmetrical Z/E-configuration in the solid state. However, the 31P NMR spectra give no indication of non-equivalence of the two phosphorus substituents in solution.
    Notes: Bis(di-tert-butylphosphino)schwefeldiimid, S(N — PtBu2)2 (1), addiert Schwefel und Selen an beide Phosphoratome unter Bildung der neuen Chalkophosphinyl-substituierten Schwefeldiimide S[N — P(Y)tBu2]2 (Y = S (2a), Se (2b)). Nach den Einkristall-Röntgenstrukturanalysen liegen 2a und 2b im Festkörper in der unsymmetrischen Z/E-Konfiguration vor. Dagegen geben die 31P-NMR-Spektren keinen Hinweis auf eine Nichtäquivalenz der beiden Phosphorsubstituenten in Lösung.
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    Enantioselektive Addition von Arylgruppen an aromatische Aldehyde mit Aryltitan-Binaphthol-Derivaten (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3673-3682 
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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: Enantioselective Addition of Aryl Groups to Aromatic Aldehydes Using Chiral Aryltitanium Binaphthol DerivativesChiral, non-racemic organotitanium reagents are generated in situ from binaphthol, chlorotriisopropoxytitanium and aryl Grignard reagents in tetrahydrofuran (THF). These reagents transfer aryl groups to aromatic aldehydes with high enantioselectivity [eq. (1)-(3)]. By this method, enantiomerically pure benzhydrols are available (3 - 13, Table 1). In the cases, in which the absolute configuration of the products is known, the reaction occurs with relative topicity lk.
    Notes: Die aus chiralem, nicht racemischem Binaphthol, Chlorotriisopropoxytitan und Aryl-magnesiumbromiden in Tetrahydrofuran (THF) in situ erzeugten Organotitanreagentien übertragen die Arylgruppe mit hoher Enantioselektivität auf aromatische Aldehyde [Gleichungen (1)-(3)]. So sind praktisch enantiomerenreine Benzhydrole zugänglich (3 - 13, Tab. 1). Die Reaktion verläuft in den Fällen, in welchen die absolute Konfiguration der Benzhydrole bekannt ist, mit relativer Topizität lk.
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    Syntheses, absorption and fluorescence spectra of 7-hydroxy-3-pyridylcoumarins, their esters, ethers, and quaternized derivatives (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3664-3672 
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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: Synthesen, Absorptions- und Fluoreszenzspektren von 7-Hydroxy-3-pyridylcumarinen, deren Ethern, Estern und quartärisierten DerivatenEs wurden 7-Hydroxycumarine 4 mit einem 2-, 3- oder 4-Pyridylsubstituenten in 3-Stellung sowie deren Ether (3), Ester (5, 6) und quartärisierten Derivate (7 - 9) mit Hilfe einer generell anwendbaren Methode hergestellt, welche von 2-Hydroxy-4-methoxybenzaldehyd (1) ausgeht. Die Absorptions- und Fluoreszenzspektren in Methanol sowie Wasser von verschiedenem pH-Wert werden angegeben und die Effekte der Substituenten auf Spektren und pKa-Werte diskutiert.
    Notes: 7-Hydroxycoumarins 4 with a 2-, 3- or 4-pyridyl substituent in position 3, their ethers (3), esters (5, 6), and quaternized derivatives (7 - 9) have been synthesized by a generally applicable method starting from 2-hydroxy-4-methoxybenzaldehyde (1). The absorption and fluorescence spectra in methanol and water of different pH values are reported, and the effects of substituents on spectra and pKa values are discussed.
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    URL: http://dx.doi.org/10.1002/cber.19851180920
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    Carbene, 30. Metallkatalysierte Zersetzung von 4-Diazomethyl-4H-pyranen - ein neuer Zugang in das Oxepin-System (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3700-3713 
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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: Carbenes, 30. Metal-catalyzed Decomposition of 4-Diazomethyl-4H-pyrans - a New Access to the Oxepin SystemElectrophilic diazoalkane substitution at the lithiated diazomethyl compounds 5a - d with the pyrylium salt 6 yields the 4-diazomethyl-4H-pyrans 7a - d. Only in the case of 5d competitive attack in the 2-position of the pyrylium salt is observed, leading ultimately to the formation of the pyrazole 9. μ-Allylpalladium chloride-catalyzed decomposition of 7a - d in benzene gives in nearly quantitative yields the oxepins 12a - d. They react with the triazoledione 14 under [4 + 2]-cycloaddition followed by a hetero Cope rearrangement producing the triazolopyridazines 17a - d. An X-ray analysis of 17b has been performed.
    Notes: Elektrophile Diazoalkansubstitution an den lithiierten Diazomethylverbindungen 5a - d mit dem Pyryliumsalz 6 liefert die 4-Diazomethyl-4H-pyrane 7a - d. Nur im Falle von 5d beobachtet man auch den Angriff in der 2-Position des Pyryliumsalzes; dies führt in letzter Konsequenz zur Bildung des Pyrazols 9. μ-Allylpalladiumchlorid-katalysierte Zersetzung von 7a - d in Benzol liefert in fast quantitativen Ausbeuten die Oxepine 12a - d. Diese reagieren mit dem Triazoldion 14 unter [4 + 2]-Cycloaddition bei nachfolgender Hetero-Cope-Umlagerung zu den Triazolopyridazinen 17a - d. Von 17b wurde eine Röntgenstrukturanalyse angefertigt.
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    URL: http://dx.doi.org/10.1002/cber.19851180923
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    Kinetische und mechanistische Untersuchungen von Übergangsmetallkomplex-Reaktionen, XVIII. Insertion von Diorganylcyanamiden in die Metall-Carbenkohlenstoff-Bindung - präparative und kinetische Untersuchungen (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3683-3699 
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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: Kinetic and Mechanistic Investigations of Transition Metal Complex Reactions, XVIII. Insertion of Diorganylcyanamides into the Metal-Carbene Bond - Preparative and Kinetic InvestigationsArylcarbene(pentacarbonyl) complexes, (CO)5M[C(Ph)R1] (M = Cr, Mo, W; R1 = Ph, OMe), react with diorganylcyanamides, R2R3N—C ≡ N (R2, R3 = Me, Et, Pr, iPr, Ph), via insertion of the C≡N group into the metal-carbene bond to give {[(arylmethylene)amino]-(diorganylamino)carbene}pentacarbonyl complexes, (CO)5M[C(NR2R3)N=C(Ph)R1]. The reaction follows a second-order rate law, first order each in the concentrations of the complex and the cyanamide. The rate constant increases slightly with increasing ability of the amino substituents R2 and R3 to donate electron density. The activation enthalpies are small (ΔH≠ = 37.5 to 40.6 kJ · mol-1), the activation entropies are strongly negative (ΔS≠ = -123 to -133 J · mol-1 · K-1). The reaction is initiated by nucleophilic attack of the cyanamide via the nitrile nitrogen at the carbene carbon.
    Notes: Arylcarben(pentacarbonyl)-Komplexe, (CO)5M[C(Ph)R1] (M = Cr, Mo, W; R1 = Ph, OMe), reagieren mit Diorganylcyanamiden, R2R3N—C ≡ N (R2, R3 = Me, Et, Pr, iPr, Ph), unter Einschiebung der C≡ N-Funktion in die Metall-Carbenkohlenstoff-Bindung zu den {[(Arylmethylen)amino](diorganylamino)carben}pentacarbonyl-Komplexen (CO)5M-[C(NR2R3)N=C(Ph)R1]. Die Reaktion erfolgt nach einem Geschwindigkeitsgesetz zweiter Ordnung, jeweils von erster Ordnung bezüglich der Komplex- und der Cyanamid-Konzentration. Die Geschwindigkeitskonstante nimmt mit steigender Donatorstärke der Amino-substituenten R2 und R3 geringfügig zu. Die Aktivierungsenthalpien sind niedrig (ΔH≠ = 37.5 bis 40.6 kJ · mol-1), die Aktivierungsentropien stark negativ (ΔS≠ = -123 bis -133 J · mol-1 · K-1). Die Reaktion wird durch einen nucleophilen Angriff des Cyanamids über den Nitril-Stickstoff am Carbenkohlenstoffatom eingeleitet.
    Additional Material: 8 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19851180922
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    Heterocyclopolyaromaten, XV. Über die Bromierung, Acetylierung und Nitrierung von (all-αS)Cyclotetrathiophen (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3714-3723 
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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: Heterocyclopolyaromatics, XV. On the Bromination, Acetylation, and Nitration of (all-αS)CyclotetrathiopheneBromination, acetylation, and nitration of (all-αS)cyclotetrathiophene (1) yielded in experiments with different substrate reagent ratios the substitution products of well defined structures: 2-bromo- (2; 29%) and 2,7,12,17-tetrabromo derivative (3; 82%), 2-acetyl- (4; 45%) and 2,7,12-triacetyl derivative (4; 45%) and 2,7,12-triacetyl derivative (5; 4%), 2-nitro- (9; 4%) and 2,7,12-trinitro derivative (10; 8%). In the acetylation and nitration reactions, two crystalline disubstitution products were formed additionally in each case. The position of the second substituent in these products is not clear today.
    Notes: Die mit verschiedenen Substrat-Reagenz-Verhältnissen durchgeführte Bromierung, Acetylierung und Nitrierung von (all-αS)Cyclotetrathiophen (1) lieferte die Substitutionsprodukte gesicherter Konstitution: 2-Brom- (2; 29%) und 2,7,12,17-Tetrabrom-Derivat (3; 82%), 2-Acetyl- (4; 45%) und 2,7,12-Triacetyl-Derivat (5; 4%) sowie 2-Nitro- (9; 4%) und 2,7,12-Trinitro-Derivat (10; 8%). Bei der Acetylierung und Nitrierung entstanden jeweils zusätzlich zwei kristalline Disubstitutionsprodukte, in denen die Stellung des zweiten Substituenten noch unklar ist.
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    URL: http://dx.doi.org/10.1002/cber.19851180924
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    Vielelektronenliganden, XII. Übergangsmetall-Liganden durch Umsetzung von Spiro[2.4]hepta-4,6-dien und Spiro[4.4]nona-1,3-dien mit Lithium-arseniden (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3724-3736 
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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: Multi Electron Ligands, XII. Transition Metal Ligands by Reaction of Spiro[2.4]hepta-4,6-diene and Spiro[4.4]nona-1,3-diene with Lithium ArsenidesConvenient one-pot syntheses of six multi electron ligands (5, 7, 11, 13, 16b, 18b) for transition metals are described, basing on fast ring opening reactions. Besides the spiro compounds, mentioned in the title, 1,2-diphenyl-1,2-diarsolane served as educt for the ring opening reactions. Some of the ligands were reacted with FeCl2 to give ferrocenophanes (21 a, b, 22) or a ferrocene (19), respectively.
    Notes: Es werden bequeme Eintopfsynthesen von sechs Vielelektronenliganden (5, 7, 11, 13, 16b, 18b) für Übergangsmetalle beschrieben, die durch rasch ablaufende Ringöffnungsreaktionen ermöglicht werden. Außer den im Titel genannten Spiroverbindungen diente 1,2-Diphenyl-1,2-diarsolan als ringöffnendes Edukt. Einige der Liganden wurden mit FeCl2 zu Ferrocenophanen (21 a, b, 22) bzw. einem Ferrocen (19) komplexiert.
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    URL: http://dx.doi.org/10.1002/cber.19851180925
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    Beiträge zur Chemie des Bors, 159. [2 + 2]-Cycloadditionen von (tert-Butylimino)(2,2,6,6-tetramethylpiperidino)boran mit Kohlenstoffdichalkogeniden (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3748-3758 
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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, 159. [2 + 2] Cycloadditions of (tert-Butylimino)(2,2,6,6-tetramethylpiperidino)borane with Carbon Dichalcogenides[2 + 2] Cycloadditions of CO2, COS, CS2, and CSe2 and the aminoiminoborane 1 give access to the azaboretidines 2-5. These decompose thermally or photolytically with formation of (CH3)3C—N =C =E′ (E′ = O, S, Se) and the dimers of the (tetramethylpiperidino)boron chalcogenides 7-9. The X-ray structure analyses of the sulfur containing heterocycles 4 and 8 reveal the presence of planar four-membered rings. The C2N-unit of the tetramethylpiperidino group in 4 approaches a perpendicular arrangement with four-membered ring (interplanar angle 72°), in 8 however, the two planes are twisted to each other by 17° only.
    Notes: CO2, COS, CS2 und CSe2 reagieren mit dem Aminoiminoboran 1 unter [2 + 2]-Cycloaddition zu den Azaboretidinen 2-5. Diese zerfallen thermisch oder photolytisch unter Abspaltung von (CH3)3C—N =C =E′ (E′ = O, S, Se) und Bildung der dimeren (Tetramethyl-piperidino)borchalkogenide 7-9. Die Röntgenstrukturanalyse der schwefelhaltigen Heterocyclen 4 und 8 zeigt planare Vierringe auf. In 4 bildet das C2N-Strukturelement der Tetramethylpiperidino-Gruppe mit der Vierring-Ebene einen Winkel von 72°, in 8 sind die beiden Ebenen dagegen nur um 17° verdrillt.
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    URL: http://dx.doi.org/10.1002/cber.19851180927
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    Vielelektronenliganden, XIII. Synthese von Übergangsmetall-Liganden mit terminalen Inden-Resten ausgehend von Spiro[cyclopropan-1,1′-inden] (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3737-3747 
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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: Multi Electron Ligands, XIII. Synthesis of Transition Metal Ligands with Terminal Indene Residues Starting from Spiro[cyclopropane-1,1′-indene]Spiro[cyclopropane-1,1′-indene] is well accessible in ca. 60% yield by reaction of indene with sodium amide and 1,2-dibromoethane. The suitability of 3 as building block for the synthesis of multi electron ligands is demonstrated by one-pot preparations of 12 ligands (4b, 4c, 5, 6, 7, 9a/b, 10, 11b, 12, 13a, 13b, 14) which can offer to a transition metal atom 7, 9, or 12 electrons, respectively, if the indenyl group acts as 5e-donor.
    Notes: Spiro[cyclopropan-1,1′-inden] (3) ist durch Umsetzung von Inden mit Natriumamid und 1,2-Dibromethan in ca. 60proz. Ausbeute bequem zugänglich. Die gute Eignung von 3 als Baustein für die Synthese von Vielelektronenliganden für Übergangsmetalle wird durch Eintopfsynthesen von 12 Liganden (4b, 4c, 5, 6, 7, 9a/b, 10, 11b, 12, 13a, 13b, 14) demonstriert, die einem Übergangsmetallatom 7, 9 oder 12 Elektronen zur Verfügung stellen können, wenn die Indenylgruppe als 5e-Donor fungiert.
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    URL: http://dx.doi.org/10.1002/cber.19851180926
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    Beiträge zur Chemie des Bors, 161. Reaktionen protonenaktiver Verbindungen mit (tert-Butylimino)(2,2,6,6-tetramethylpiperidino)boran (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3759-3770 
    Details
    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, 161. Reactions of Protic Reagents with (tert-Butylimino)(2,2,6,6-tetramethylpiperidino)boraneThe aminoiminoborane 2 adds protic reagents of type HX (X = OH, OR, OCOR, SH, SR, NH2, NHR, NHNR2) across the formal BN triple bond regiospecifically forming (tert-butylamino)(2,2,6,6-tetramethylpiperidino)boranes (3-7, 12, 13, 15, 16a,b, 17-27) which are inert towards ligand redistribution. The relative rates of addition are primarily governed by steric factors (NH3 〉 NH2R 〉 HNR2; HOR 〉 HSR 〉 HNR2). Bulky amines HNR2 will not add to 2. Excess HX (X = OH, OR, OC(O)R) reacts with the boranes formed on 1:1 addition by breaking BN bonds; however, no prediction can be made concerning which BN bond in tmp[(CH3)3CNH]BX will be cleaved.
    Notes: Das Aminoiminoboran 2 addiert protonenaktive Verbindungen HX (X = OH, OR, OCOR, SH, SR, NH2, NHR, NHNR2) regiospezifisch an die formale BN-Dreifachbindung. Dabei entstehen gegen Substituentenaustausch inerte (tert-Butylamino)(2,2,6,6-tetramethylpiperidino)borane (3 - 7, 12, 13, 15, 16a,b, 17 - 27). Die Anlagerungsgeschwindigkeit hängt qualitativ von sterischen Faktoren ab (NH3 〉 NH2R 〉 HNR2; HOR 〉 HSR 〉 HNR2). Bei sterischer Überfrachtung unterbleibt die Anlagerung an 2. Bei HX-Überschuß (X = OH, OR, OC(O)R) reagieren die durch 1:1-Addition entstandenen Borane unter Spaltung von BN-Bindungen, jedoch ist nicht vorhersehbar, welche der beiden BN-Bindungen in tmp[(CH3)3CNH]BX dabei gelöst wird.
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    URL: http://dx.doi.org/10.1002/cber.19851180928
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    Azulene durch Vakuumpyrolyse von Halogentricyclo[7.1.0.04,6]decadienen (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3805-3816 
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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: Azulenes by Vacuum Pyrolysis of Halotricyclo[7.1.0.04,6]decadienesDouble addition of halocarbenes or -carbenoids to cyclooctatetraene yields the title compounds 2. Pyrolysis of these (700°C, 0.01 mbar) gives azulenes of varying substitution patterns (4, 5, 6, and/or 7) which carry one substituent in each ring. Structure assignments follow from 1H NMR spectroscopy, sometimes after electrophilic introduction of the trifluoroacetyl residue. Nucleophilic substitutions of azulenes with two halogen atoms (giving compounds 8 or 9) occur only in the 7-membered ring; only 4b and CuCN yield some 11 in addition to 10.
    Notes: Doppelte Addition von Halogencarbenen bzw. -carbenoiden an Cyclooctatetraen liefert die Titelverbindungen 2. Deren Pyrolyse bei etwa 700°C und 0.01 mbar führt zu Azulenen mit unterschiedlichen Substitutionsmustern (4, 5, 6 und/oder 7), die in jedem Ring jeweils einen Substituenten tragen. Strukturzuordnungen ergeben sich auf Grund der 1H-NMR-Spektren, z.T. nach elektrophiler Substitution in 1- oder 3-Stellung mit dem Trifluoracetylrest. Nucleophile Substitutionen der Azulene mit zwei Halogenatomen zu den Verbindungen 8 oder 9 erfolgen ausschließlich im 7-Ring; allein 4b und CuCN geben neben 10 wenig 11.
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    URL: http://dx.doi.org/10.1002/cber.19851180931
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