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  • Inorganic Chemistry  (5,390)
  • Industrial Chemistry  (1,701)
  • Aerodynamics
  • Seismology
  • 1975-1979  (4,360)
  • 1950-1954  (3,056)
Collection
Years
Year
  • 1
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    In:  Bull. Seism. Soc. Am., Washington D.C., Bundesanstalt für Geowissenschaften und Rohstoffe, vol. 69, no. 4, pp. 1027-1038, pp. L09611
    Publication Date: 1979
    Keywords: Fore-shocks ; Earthquake ; Discrimination ; Earthquake precursor: prediction research ; Spectrum ; Corner frequency ; Seismology ; Body waves ; BSSA
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  • 2
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    In:  Geophys. J. R. astr. Soc., Warszawa, Bundesanstalt für Geowissenschaften und Rohstoffe, vol. 57, no. 1, pp. 537-555, pp. 2121
    Publication Date: 1979
    Keywords: Subduction zone ; Seismicity ; Seismology ; South ; America ; GJRaS
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  • 3
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    In:  Geophys. J. R. astr. Soc., London, Elsevier, vol. 57, no. 8, pp. 353-379, pp. 2083, (ISBN 1-86239-117-3)
    Publication Date: 1979
    Keywords: earth mantle ; Seismology ; P-waves ; Shear waves ; Q-structure ; Quality factor ; GJRaS
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  • 4
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    In:  Geophys. J. R. astr. Soc., London, Elsevier, vol. 57, no. 8, pp. 381-395, pp. 2083, (ISBN 1-86239-117-3)
    Publication Date: 1979
    Keywords: earth mantle ; Seismology ; P-waves ; Shear waves ; Q-structure ; Quality factor ; GJRaS
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  • 5
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    In:  Earthquake Information Bulletin, Münster, Amer. Sc., vol. 11, no. 4, pp. 170-174, pp. 1228, (ISBN 0-471-26610-8)
    Publication Date: 1979
    Keywords: Seismology ; Review article ; Project report/description
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  • 6
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    In:  J. Geophys. Res., Luxembourg, Conseil de l'Europe, vol. 84, no. 7055, pp. 2348-2350, pp. B05S07, (ISBN: 0534351875, 2nd edition)
    Publication Date: 1979
    Keywords: Seismology ; Magnitude ; Source parameters ; seismic Moment ; Statistical investigations ; JGR
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  • 7
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    In:  Bull. Seism. Soc. Am., Amsterdam, Elsevier Scientific Publishing Company, vol. 69, no. 2, pp. 1645-1670, pp. 2265, (ISSN 0016-8548, ISBN 3-510-50045-8)
    Publication Date: 1979
    Keywords: Seismology ; Strong motions ; BSSA
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  • 8
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    In:  Tectonophys., Bonn, 3-4, vol. 53, no. 10, pp. 325-333, pp. L10306, (ISSN: 1340-4202)
    Publication Date: 1979
    Keywords: Seismology ; Earthquake
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  • 9
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    In:  Sci. Am., Reykjavík, Icelandic Meteorological Office, Ministry for the Environment University of Iceland, vol. 240 , no. 1, pp. 92-107, pp. TC1011, (ISSN 0016-8548, ISBN 3-510-50045-8)
    Publication Date: 1979
    Keywords: Seismology ; Earth model, also for more shallow analyses ! ; Lithosphere ; earth mantle ; SciAm
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  • 10
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    In:  Bull. Seism. Soc. Am., Kunming, China, 4, vol. 69, no. 4, pp. 1209-1214, pp. L13613, (ISSN: 1340-4202)
    Publication Date: 1979
    Keywords: Magnitude ; Seismology ; Seismicity ; BSSA
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  • 11
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    In:  Geophys. J. R. astr. Soc., Zagreb, 3-4, vol. 57, no. 1, pp. 609-638, pp. B06305, (ISSN: 1340-4202)
    Publication Date: 1979
    Keywords: Seismology ; Attenuation ; Inelastic ; Magnitude ; GJRaS
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  • 12
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    In:  Bull. Seism. Soc. Am., Luxembourg, Conseil de l'Europe, vol. 69, no. 1, pp. 1133-1148, pp. L09610, (ISSN: 1340-4202)
    Publication Date: 1979
    Keywords: Seismology ; Shear waves ; Surface waves ; Phase velocity ; BSSA
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  • 13
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    In:  Rev. Geophys. Space Phys., San Francisco, Schweizerbart'sche Verlagsbuchhandlung, vol. 17, no. B10, pp. 328-336, pp. B10404, (ISSN 0016-8548, ISBN 3-510-50045-8)
    Publication Date: 1979
    Keywords: Source ; Seismology ; Review article
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  • 14
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    In:  J. Geophys. Res., Basel, Elsevier Science Publishers, vol. 84, no. B9, pp. 4749-4762, pp. L15S20, (ISSN: 1340-4202)
    Publication Date: 1979
    Keywords: Teleseismic events ; Seismology ; Volcanology ; Velocity depth profile ; USA ; Geol. aspects ; Body waves ; JGR
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  • 15
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    In:  Geophys. J. R. astr. Soc., Hannover, Conseil de l'Europe, vol. 59, no. 1, pp. 315-323, pp. L24314, (ISSN: 1340-4202)
    Publication Date: 1979
    Keywords: Dispersion ; Frequency ; Seismology ; GJRaS
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  • 16
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    In:  J. Geophys., Würzburg, Physica-Verlag, vol. 45, no. 1, pp. 337-340, pp. L24313, (ISSN: 1340-4202)
    Publication Date: 1979
    Keywords: P-waves ; Seismic arrays ; Seismology ; ConvolutionR
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  • 17
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    In:  J. Geophys. Res., San Francisco, Pergamon, vol. 84, no. B5, pp. 2243-2250, pp. B05315, (ISSN: 1340-4202)
    Publication Date: 1979
    Keywords: seismic Moment ; Stress drop ; Stress ; Strength ; Seismology ; Modelling ; Source parameters ; Inhomogeneity ; JGR
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  • 18
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    In:  Geophys. J. R. astr. Soc., Zagreb, 3-4, vol. 57, no. 5372, pp. 609-638, pp. B06305, (ISSN: 1340-4202)
    Publication Date: 1979
    Keywords: Seismology ; Attenuation ; Magnitude ; Nuclear explosion ; GJRaS
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  • 19
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    In:  Schweiz. mineral. petrogr. Mitt., Bonn, 3-4, vol. 59, no. 10, pp. 127-132, pp. L10306, (ISSN: 1340-4202)
    Publication Date: 1979
    Keywords: Seismicity ; Seismology ; Fault plane solution, focal mechanism ; Muller
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  • 20
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    In:  J. Geophys. Res., New York, August, vol. 84, no. 3-4, pp. 2251-2261, pp. 1610, (ISSN: 1340-4202)
    Publication Date: 1979
    Keywords: Seismology ; Stress ; Stress drop ; Energy (of earthquakes) ; Source parameters ; JGR
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  • 21
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    In:  Wave Motion, Tulsa, 3-4, vol. 1, no. 13, pp. 187-192, pp. B10303, (ISBN: 0-12-018847-3)
    Publication Date: 1979
    Keywords: Dislocation ; cracks and fractures (.NE. fracturing) ; Seismology
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  • 22
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    In:  J. Geophys. Res., London, Army Corps of Engineers, Woodward-Clyde Consultants, vol. 84, no. 5, pp. 4583-4591, pp. 1013, (ISBN: 0-12-018847-3)
    Publication Date: 1979
    Keywords: Subduction zone ; Seismology ; Seismicity ; Volcanology ; JGR
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  • 23
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    In:  Bull. Seism. Soc. Am., Dordrecht, Martinus Nijhoff Publishers, vol. 69, no. 3, pp. 893-909, pp. L11307, (ISSN: 1340-4202)
    Publication Date: 1979
    Keywords: Seismology ; Intensity ; Magnitude ; BSSA ; body wave Magnitude
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  • 24
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    In:  Phys. Earth Plan. Interiors, Kyoto, AGU, vol. 18, no. B1, pp. 176-196, pp. L24302, (ISSN: 1340-4202)
    Publication Date: 1979
    Keywords: Seismology ; Earthquake ; PEPI
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  • 25
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    In:  J. Geophys. Res., Berlin, Pergamon, vol. 84, no. B2, pp. 672-678, pp. B04306, (ISSN: 1340-4202)
    Publication Date: 1979
    Keywords: Velocity ; Seismology ; Earthquake precursor: prediction research ; Earthquake precursor: Vp/Vs anomalies ; JGR ; Body waves
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  • 26
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    In:  Geophys. Prosp., Luxembourg, Conseil de l'Europe, vol. 27, no. 1, pp. 1-15, pp. 1068, (ISSN: 1340-4202)
    Publication Date: 1979
    Keywords: Detectors ; Seismology ; Statistical investigations ; CoherencyE
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  • 27
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    Elsevier
    In:  Amsterdam, 490 pp., Elsevier, vol. 11, no. Publ. No. 12, pp. 127, (3-540-43395-3)
    Publication Date: 1979
    Keywords: Seismology ; Textbook of geophysics
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  • 28
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    In:  Geophys. J., vol. 58, no. B11, pp. 91-105
    Publication Date: 1979
    Keywords: Seismology ; Layers ; Dispersion ; Frequency ; Synthetic seismograms
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  • 29
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    In:  Rev. Roum. Géol., Géophys. et Géogr. - Géophysique, Münster, 3, vol. 23, no. 3-4, pp. 39-49, pp. L12311, (ISBN 0-471-26610-8)
    Publication Date: 1979
    Keywords: Source parameters ; Seismology ; EUROPROBE (Geol. and Geophys. in eastern Europe)
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  • 30
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    In:  J. Geophys. Res., Berlin, Inst. Electrical & Electronics Engineers, vol. 84, no. 4, pp. 3615-3622, pp. B04307, (ISBN: 0534351875, 2nd edition)
    Publication Date: 1979
    Keywords: Travel time ; Inversion ; Data analysis / ~ processing ; Seismics (controlled source seismology) ; Seismology ; JGR
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  • 31
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    Naval Ocean Systems Center
    In:  report, San Diego, Naval Ocean Systems Center, vol. 1, no. paper SPWLA 90-C, pp. M1-M4, (ISBN 3-933346-037)
    Publication Date: 1979
    Keywords: Seismology ; Seismics (controlled source seismology) ; Power spectrum ; Spectrum
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  • 32
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    Inst. f. Geophys., Univ. Stuttgart
    In:  Diplomarbeit, Granada, 10-12 June 1999, Inst. f. Geophys., Univ. Stuttgart, vol. 339-350, no. 32, pp. 103-108, (ISBN 3-933346-037)
    Publication Date: 1979
    Keywords: Spectral analysis ; Spectrum ; Earthquake ; Seismology ; Fracture
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  • 33
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    In:  Preprint, Novosibirsk, Air Force Geophysics Laboratory, no. AFGL-TR-87-0230, pp. 103-155
    Publication Date: 1979
    Keywords: Modelling ; Seismology ; Seismics (controlled source seismology) ; Wave propagation
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  • 34
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    Univ. Calif.
    In:  Ph.D. Thesis, San Diego, Univ. Calif., vol. 11, no. PEER Utilities Pgm. Rep. 2000/17, 24 pp., pp. 207
    Publication Date: 1979
    Keywords: Modelling ; Layers ; Synthetic seismograms ; Seismology
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  • 35
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    Forschungsinstitut für militärische Bautechnik
    In:  report, Zürich, Forschungsinstitut für militärische Bautechnik, vol. 10, no. FMB 79.10, pp. 2985-3018
    Publication Date: 1979
    Keywords: Nuclear explosion ; Seismology ; Buechi ; Buchi
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  • 36
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    Ludwig-Maximilians-Universität
    In:  Diplomarbeit, München, Ludwig-Maximilians-Universität, vol. 10, no. 28, pp. 309-314
    Publication Date: 1979
    Keywords: Teleseismic events ; Velocity analysis ; earth mantle ; Seismology ; Bruestle ; Brustle
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  • 37
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    In:  Geophys. J. R. astr. Soc., Basle, Wiley, vol. 60, no. 5441, pp. 459-487, pp. 1264, (ISSN: 1340-4202)
    Publication Date: 1979
    Keywords: Source ; Seismology ; Fault plane solution, focal mechanism ; GJRaS
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  • 38
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    Bundesanstalt f. Geowissenschaften und Rohstoffe
    In:  Hannover, Bundesanstalt f. Geowissenschaften und Rohstoffe, vol. 25, no. Publ. No. 12, pp. 95-104, (ISBN: 0-08-043930-6)
    Publication Date: 1979
    Keywords: Seismology ; Detectors ; Filter- ; Broad-band
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  • 39
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    Hallwag
    In:  Stuttgart, Hallwag, vol. 30, no. Publ. No. 12, pp. 95-104, (ISBN 0-865-42078-5)
    Publication Date: 1979
    Keywords: Earthquake ; Seismology ; Textbook of geophysics
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  • 40
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    Caltech
    In:  Ph.D. Thesis, Pasadena, CA., Caltech, vol. C 560, 183 pp., no. PL-TR-91-2212(I), pp. 79-84, (ISBN 3-933346-037)
    Publication Date: 1979
    Keywords: Detectors ; sta ; Seismology ; Seismic networks ; High frequency ...
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  • 41
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    In:  Preprint, Beijing, Halliburton Logging Services, vol. C 560, 183 pp., no. PL-TR-91-2212(II), pp. 938-939, (ISBN 3-933346-037)
    Publication Date: 1979
    Keywords: Seismology ; Seismics (controlled source seismology) ; Scattering ; Coda (waves, ~ of seismograms) ; Wave propagation ; Acoustics
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  • 42
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    Inst. f. Meteorol. und Geophys., Goethe Univ. Frankfurt
    In:  Diplomarbeit, Roma, Inst. f. Meteorol. und Geophys., Goethe Univ. Frankfurt, vol. C 560, 183 pp., no. 78 (?), pp. 193-210, (ISBN 3-933346-037)
    Publication Date: 1979
    Keywords: Seismology ; Seismic arrays ; Data analysis / ~ processing ; Energy (of earthquakes)
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  • 43
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    Lawrence Livermore National Laboratory
    In:  rept., Livermore, Calif., Lawrence Livermore National Laboratory, vol. 10, no. UCID-18099, pp. 1358-1361, (ISBN 3-933346-037)
    Publication Date: 1979
    Keywords: Review article ; Deep seismic sounding (espec. cont. crust) ; CRUST ; earth mantle ; Seismology ; EUROPROBE (Geol. and Geophys. in eastern Europe)
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  • 44
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    U. S. Geol. Surv.
    In:  Prof. Paper, Menlo Park, California, U. S. Geol. Surv., vol. 1034, no. 77-3, pp. 1-74, (ISBN 3-933346-037)
    Publication Date: 1979
    Keywords: Deep seismic sounding (espec. cont. crust) ; Velocity depth profile ; USGS ; USA ; Seismics (controlled source seismology) ; Seismology
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  • 45
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    In:  J. Geophys. Res., Zagreb, Conseil de l'Europe, vol. 84, no. 4, pp. 3543-3552, pp. L02307, (ISSN 0343-5164)
    Publication Date: 1979
    Keywords: Seismology ; Fault plane solution, focal mechanism ; Surface waves ; Tectonics ; Source ; JGR
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  • 46
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    In:  Bull. Seism. Soc. Am., Zagreb, Conseil de l'Europe, vol. 69, no. 4, pp. 1-15, pp. L02307, (ISSN 0343-5164)
    Publication Date: 1979
    Keywords: Seismology ; Dislocation ; SH waves ; Source ; BSSA
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  • 47
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    Stanford University, California
    In:  Ph.D. Thesis, La Jolla, CA, Stanford University, California, vol. 1034, no. 77-767, pp. 293-297, (ISBN 3-933346-037)
    Publication Date: 1979
    Keywords: Seismology ; Seismic networks ; Seismic arrays ; Statistical investigations
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  • 48
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    U. S. Geol. Surv.
    In:  Open-File Report, Houston, U. S. Geol. Surv., vol. C 560, 183 pp., no. 79-431, pp. 1-57, (ISBN 3-933346-037)
    Publication Date: 1979
    Keywords: Source parameters ; Seismology ; Magnitude ; Hypocentral depth ; Location ; software ; USGS
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  • 49
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    NOAA, U. S. Department of Commerce
    In:  report, Houston, NOAA, U. S. Department of Commerce, vol. 10, no. SE-20, pp. 206-209, (ISBN 0 08 042822 3)
    Publication Date: 1979
    Keywords: Handbook of geophysics ; Seismology ; Instruments ; BIBTEX?
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  • 50
    Publication Date: 2019-07-13
    Description: The paper describes the development of a thick (t/c = 0.18) transonic, multifoil, blown augmentor-wing section and discusses the results of a series of wind-tunnel tests on the configuration. The results show that the blown multifoil section enjoys two advantages over a conventional unblown single-foil supercritical section or the same overall thickness-chord ratio: 1) "effective" drag reduced by blowing, and 2) increased drag rise Mach number (M(sub D) = 0.75); they also demonstrate that augmentor blowing improves the buffet boundaries of the section. Thus, overall, it has been shown that the augmentor flap configuration is capable of extending the speed range of a jet transport aircraft to the very low approach speeds required by STOL aircraft [as demonstrated by the NASA/DITC (Canadian Department of Industry Trade and Commerce) augmentor-wing STOL research aircraft] and also to the high subsonic speed required for cruise, where it is shown to be competitive with the plain supercritical airfoil.
    Keywords: Aerodynamics
    Type: AIAA Paper 77-606 , Journal of Aircraft; 15; 755-761|V/STOL Conference; Jun 06, 1977 - Jun 08, 1977; Palo Alto, CA; United States
    Format: text
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  • 51
    Electronic Resource
    Electronic Resource
    Springer
    Pure and applied geophysics 117 (1979), S. 1045-1049 
    ISSN: 1420-9136
    Keywords: Seismology ; Surface waves
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Description / Table of Contents: Summary Alsop's method (1966) for the non-normal passage of surface waves through a vertical discontinuity is improved by using a new functional to be made stationary on the plane of discontinuity. The modified functional has the dimension of an energy flux and is characterized by the discontinuous surface wave displacements and stresses on the vertical discontinuity. Model calculations which were carried out for SV-waves and Love waves show that the new version of Alsop's method yields in all respects more consistent results than the old one.
    Notes: Zusammenfassung Die Methode von Alsop (1966) für den Durchgang von schräg einfallenden Oberflächenwellen durch eine vertikale Diskontinuität wird durch Verwendung eines neuen Funktionals, das auf der Diskontinuitätsfläche stationär sein soll, verbessert Das modifizierte Funktional hat die Dimension eines Energieflusses und wird durch diejenige Spannungs- und Verschiebungsdiskontinuität charakterisiert, die durch das Oberflächenwellenfeld auf der Diskontinuitätsfläche erzeugt wird. Modellrechnungen für SV-Wellen und Lovewellen zeigen, daß die neue Version von Alsoos Verfahren in jeder Hinsicht konsistentere Ergebnisse als die bisherige liefert.
    Type of Medium: Electronic Resource
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  • 52
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1252-1259 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Macrocyclic and Linear Borazine-Arene CompoundsMacrocyclic oligomeric condensates formed by an alternate sequence of 2,4-difunctional borazines and aromatic 1,3-dihydroxy, 1,3-diamino, or l-amino-3-hydroxy compounds (1-4) are less stable than corresponding systems formed by O- or NH-linked borazines only. Besides of these compounds which have a pseudocage structure like the cyclic oligoborazines, several noncyclic oligomeric condensates have been prepared which exist of mono- or difunctional borazines and di- or monofunctional phenols, thiophenols, or aromatic amines (5- 13). The substances are characterized by analyses, mass and 1H-NMR spectroscopy.
    Notes: Oligomere, makrocyclische Kondensate, die alternierend aus 2,4-difunktionellen Borazinen und aromatischen 1,3-Dihydroxy-, 1,3-Diamino- oder 1-Amino-3-hydroxy-Verbindungen gebildet werden (1-4), sind weniger stabil als entsprechende Systeme, die nur aus O- oder NH-verbrückten Borazinen bestehen. Außer diesen Verbindungen, die ebenso wie die cyclischen Oligoborazine Pseudokäfigstruktur besitzen, wurden mehrere nicht cyclische oligomere Kondensate aus mono- oder difunktionellen Borazinen und di- bzw. monofunktionellen Phenolen, Thiophenolen bzw. aromatischen Aminen dargestellt (5-13). Die Verbindungen sind analytisch und durch ihre Massen- und 1H-NMR-Spektren charakterisiert.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
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  • 53
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1464-1469 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation and X-Ray Structural Analysis of an Adamantyl-spirophosphorane, C10HI5P(O2C6H4)Reaction of (1-adamantyl)tetrafluorophosphorane with catechol bis(trimethylsilyl ether) yielded the spirophosphorane C10H15P(O2C6H4)2 (4). Crystals of 4 are orthorhombic. P212121, with a = 668.5 (1), b = 1575.8 (2), c = 1755.1 (2) pm, Z = 4, R = 0.058. C2v,-distorted rectangular pyramidal coordination is observed at phosphorus.
    Notes: Durch Umsetzung von (1-Adamantyl)tetrafluorphosphoran mit Brenzcatechin-bis(trimethylsilylether) wurde das Spirophosphoran C10H15P(O2C6H4)2 (4) erhalten. 4 kristallisiert orthorhombisch, P212121, mit a = 668.5 (1), b = 1575.8 (2), c = 1755.1 (2) pm, Z = 4,. R, = 0.058. Es wird C2v-verzerrte rechteckig-pyramidale Koordination am Phosphor gefunden.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1470-1472 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reactions of Enolic Sugar Derivatives, XIV. A New Synthesis of L-Fucosamine by „Azido-nitration“ of L-FucalStarting from 3,4-di-O-acetyl-L-fucal (2) 3,4-di-O-acetyl-2-azido-2-deoxy-α-L-fucopyranosyl nitrate (3) was prepared by azido-nitration. Ammonolysis and reacetylation led to 1-N,3,4-O-triacetyl-2-azido-2-deoxy-α-L-fucopyranosylamine (4). De-O-acetylated 4 (5) was hydrogenized to yield crude l-N-acetyl-2-amino-2-deoxy-α-L-fucopyranosylamine which after acid hydrolysis yielded L-fucosamine (1).
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1477-1479 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The Yellow Isomer of (1,5-Diphenylformazanyl)glyoxylic AcidThe yellow isomer is shown to be 4,4-dihydroxy-l-phenyl-3-phenylazo-2-pyrazolin-5-one (3), the hydrate of the pyrazolin-4,5-dione 4. Treatment of 4 with a solution of potassium -tert- butoxide in dimethylsulfoxide leads to the formation of a radical anion identified as 5 by ESR.
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1486-1490 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reactions of Complex Ligands, XV. Synthesis of the Furan Skeleton from a Carbene Ligand, a Carbonyl Ligand, and an AlkynePentacarbonyl[ferrocenyl(methoxy)carbene]chromium(0) (1) reacts with tolan (2) in dibutyl ether on warming to give tricarbonyl[(5-ferrocenyl-2-methoxy-3-η6-phenyl-4-phenyl)furan]-chromium(O) (3). The structure of the reaction product was established by an X-ray analysis.
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1491-1492 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Studies on the Field of Natural Products Chemistry, 71. Psoralen and Angelicin by Reaction of 7-Hydroxycoumarin with 4-Chloro-1,3-dioxolan-2-oneDirect condensation of umbelliferone (1) with 4-chloro-1,3-dioxolan-2-one (2) yields 15% psoralen (3) and 20% angelicin (4).
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1495-1497 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: About the Formation of 2-Ethylthio-3-phenylindene from 2-Ethylthio-1,1-diphenyl-2-propen-1-ol2-Ethylthio-3-phenylindene (6) is formed in 75% yield by heating the tertiary carbinol 2b in toluene with catalytic amounts of p-toluenesulfonic acid.
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  • 59
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    Berichte der deutschen chemischen Gesellschaft 112 (1979) 
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    Keywords: Chemistry ; Inorganic Chemistry
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1-15 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Electrophilic Aromatic Substitution Reactions with Protonated 1,3-Diazines, I. Preparation and Properties of 4-Aryl-substituted 3,4-Dihydropyrimidine DerivativesIn the presence of trifluoroacetic acid, pyrimidine and 5-methylpyrimidine react with active aromatic compounds to form stable 4-aryl-substituted 3,4-dihydropyrimidinium salts, e.g. 1, 2, 6. From these, the dihydro bases 7 or 8 can be obtained which are readily oxidized to 4-aryl-substituted pyrimidines 9. 2- and/or 4-substituted pyrimidines as well as 2-amino- and 2-mercaptopyrimidines react with phenols to form benz[g][1,3,5]oxadiazocines 3 and 10. The mechanism of this novel reaction is apparently best described as an aromatic electrophilic substitution by the protonated pyrimidine derivative. The observed reactivity of different diazines is in accordance with frontier orbital arguments, using HMO-coefficients.
    Notes: Bei Gegenwart von Trifluoressigsäure reagieren Pyrimidin und 5-Methylpyrimidin mit aktiven aromatischen Verbindungen zu stabilen 4-arylsubstituierten 3,4-Dihydropyrimidinium-Salzen, z. B. 1, 2, 6, aus denen sich die zugrunde liegende Dihydrobase 7 bzw. 8 erhalten läßt, die ihrerseits leicht zu 4-arylsubstituierten Pyrimidinen 9 oxidiert werden kann. 2- und/oder 4-substituierte Pyrimidine sowie 2-Amino- und 2-Mercaptopyrimidine bilden mit Phenolen Benz[g][1,3,5]oxadiazocine der (Konstitution 3a - f und 10. Als Reaktionsmechanismus wird eine elektrophile Substitutionsreaktion durch das protonierte Pyrimidinderivat vorgeschlagen. Die beobachtete Reaktivität der verschiedenen Diazine steht im Einklang mit dem Grenzorbital-Modell auf der Basis der HMO-Koeffizienten.
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 42-56 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Rearrangements of Free Radicals, VII. Electrocyclic and Sigmatropic Rearrangements of Bicyclo[3.1.0]hexenyl RadicalAbstraction of an allylic hydrogen from bicyclo[3.1.0]hex-2-ene (1) leads to the bicyclic allyl radical 2. Electrocyclic ring opening to the cyclohexadienyl radical 3 could not be observed in solution up to + 70°C. Only the product analysis of a thermolysis (130°C) of di-tert-butylperoxide in presence of 1 evidenced the possibility of ring opening with the formation benzene. In adamantane matrix 2 rearranges at -50°C in 3 (ΔG≠ = 68.6 ± 2.0 kJ/mol). In matrix bimolecular termination reactions are prohibited. Therefore rearrangements with activation barriers greater than those of diffusion controlled reactions can easily be observed. By this method a degenerate 1,4-sigmatropic rearrangement of the methylene bridge in 2 could be proven. For this purpose specifically in 2- and 3-position deuterated derivatives of 1 were synthesized. The sigmatropic reaction follows from the statistical distribution of deuterium in the cyclohexadienyl radical over the carbon atoms of the former five-membered ring.
    Notes: Durch Abstraktion eines allylischen Wasserstoffatoms aus Bicyclo[3.1.0]hex-2-en (1) läßt sich das bicyclische Allylradikal 2 erzeugen. Eine Ringöffnung zum Cyclohexadienylradikal 3 konnte in Lösung ESR-spektroskopisch bis + 70°C nicht beobachtet werden. Die Produktanalyse einer Thermolyse (130°C) von Di-tert-butylperoxid in Gegenwart von 1 erwies mit dem Auftreten von Benzol die grundsätzliche Möglichkeit zur elektrocyclischen Ringöffnung. In Adamantanmatrix lagert das durch Röntgenbestrahlung aus 1 erzeugte 2 bereits bei -50°C in 3 um (ΔG≠ = 68.6 ± 2.0 kj/mol). Die Matrixmethode macht durch die Unterdrückung bimolekularer Abreaktionen von 2 auch den Nachweis einer degenerierten sigmatropen 1,4- Verschiebung der Methylenbrücke möglich. Hierzu wurden in 2- bzw. 3-Stellung deuterierte Derivate von 1 dargestellt. Der Nachweis der sigmatropen Wanderung ergibt sich aus der statistischen Verteilung des Deuteriums im Cyclohexadienylradikal über die C-Atome. des ehemals fünfgliedrigen Ringes.
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 99-106 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Transition Metal Sulfur Ylide Complexes, VII. η5-Thiacyclohexadienyl 1-Oxide as Novel Ligand in Complex AnionsFrom the reaction of syn-tricarbonyl(1-methyl-3,5-diphenylthiabenzene 1-oxide)chromium, molybdenum, and -tungsten (2a-c) with disodium tetracarbonylferrate or lithium diphenyl-phosphide the alkali salts of complex anions (3a-c, 5a-c) are obtained. They contain the novel ligand η5 -thiacyclohexadienyl 1-oxide. The alkali salts are converted into the tetraethylammonium salts 4a-c, which are characterized by analytical and spectroscopical data.
    Notes: Bei der Umsetzung von syn- Tricarbonyl(1-methyl-3,5-diphenylthiabenzol-1-oxid)chrom, -molybdän und-wolfram (2a-c) mit Dinatrium-tetracarbonylferrat oder Lithium-diphenylphosphid entstehen die Alkalisalze komplexer Anionen mit η5-Thiacyclohexadienyl-1-oxid als neuartigem Liganden (3a-c, 5a-c). Diese werden in die Tetraethylammoniumsalze 4a-c übergeführt und als solche auf analytischem und spektroskopischem Wege charakterisiert.
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    Description / Table of Contents: The Racemization of Spirocyclic Pentaaryl Derivatives of Group 5 A Elements. I H NMR Investigations with Overcrowded Asymmetric Phosphoranes, Arsoranes, and StiboranesThe two different methyl positions of bis-2,2′-biarylylenephosphorane 7, the corresponding arsoranes 8a, b, and the analogous stiborane 9 are reversibly equilibrated at elevated temperatures with free enthalpies of activation of 18.2 (76.0), 17.2 (72.2), ≈ 22.5 (94.2), and 15.4 (64.6) kcal(kJ)/mol. Starting with the trigonal bipyramidal ground state conformations C and ∪ (fig. 2) these ligand exchange phenomena can be interpreted in the framework of the pseudorotation process on the basis of trigonal bipyramidal transition states of type A with diequatorial biarylylene groups.
    Notes: Die beiden unterschiedlichen Methyl-Positionen des Bis-2,2′-biarylylenphosphorans 7, der entsprechenden Arsorane 8a, b und des analogen Stiborans 9 werden bei erhöhten Temperaturen mit freien Aktivierungsenthalpien von 18.2 (76.0), 17.2 (72.2). ≈ 22.5 (94.2) und 15.4 (64.6) kcal(kJ)/mol reversibel äquilibriert. Ausgehend von den trigonal-bipyramidalen Grundzustandskonformationen C und ∪ (Abb. 2) lassen sich diese Ligandenaustauschphänomene im Rahmen des Pseudorotationsprozesses auf der Basis trigonal-bipyramidaler Übergangszustände des Typs A (Abb. 2) mit diäquatorialen Biarylylen-Gruppen interpretieren.
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 310-348 
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    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Light-induced Reactions, XIII. On the Seco-isomeric Dienylketene Related to 2,4-Androstadien-1-oneThe steroidal 2.4-cyclohexadienone 3 photochemically affords the diastereomer 4. Both the configurational isomers differ exceedingly in their chiroptical properties. Their respective contribution to the photostationary state depends on the wave-length of the light and the solvent utilized. The dienylketene 5 can be determined spectroscopically as a transient. It is not trapped by 2,2,2-trifluoroethanol; cyclohexylamine, however, furnishes the 1,6-adduct 7a and/or the 1,2-adduct 6 a owing to the concentration and wave-length (365 or 313 nm) used.
    Notes: Das steroidale 2,4-Cyclohexadienon 3 geht photochemisch in das Diastereomere 4 über. Beide Konfigurationsisomere unterscheiden sich deutlich in ihren chiroptischen Eigenschaften. Ihr jeweiliger Anteil im photostationären Zustand hängt von der Wellenlänge des Lichts und dem Lösungsmittel ab. Das Dienylketen 5 läßt sich als Transient spektroskopisch nachweisen. Es wird von 2,2,2-Trifluorethanol nicht, von Cyclohexylamin je nach Konzentration und Wellenlänge (365 oder 313 nm) als 1,6-Addukt 7a und/oder als 1,2-Addukt 6a abgefangen.
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 773-775 
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    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Dimerization of Diphenyl(trifluoroacetyl)phosphane OxideAt -25°C the phosphane oxide CF3C[(O)P(O)Ph2]2OC(O)CF3 (1) dimerizes to the trifluoroacetate CF3C[(O) PPh2]2OC(O)CF3 (2a), which is sensitive to hydrolysis and, at 40°C is transformed irreversibly into the phosphinate CF3C[(O)PPh2][OP(O)Ph2]C(O)CF3(3a). In contrast to 2a, the thermally more stable homologous octanate C7F15C[(O)PPh2]2OC(O)C7F15 (2b) is obtained from Ph2PCI and C7F15CO2H.
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 763-772 
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    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation and Reactive Behaviour of Acyldiorganylphosphane OxidesThe acylphosphane oxides RC(O)P(O)R′R″ (3) are obtained in the case of 3a - e by oxidation of the acylphosphanes RC(O)PR′R″ (1a - e) with rigorously dried oxygen. 3c - e are also formed from the anhydrides (RCO)2O (R = CH3 CF3) and the phosphane oxides XP(O)R′R″ (2c′ d′). 3f only results from ClPPh2 and formic acid [eqs. (2a - c)]. 3d, e dimerize to the phosphinates RC[Ph2P(O)][OP(O)Ph2]C(O)R (4d, e)[eq.(3)] Heating of 3e with ClRh(PPh3)3 causes elimination of CO and formation of C2F6 and [Ph2P(O) — ]2 [eq. (4)]. Thermolysis of 3a - e generates the ketenes X2C2O (X = H, F) and the phosphane oxides 2a′ - e′ [eq. (5)], whereas 3f yields CO and 2d′ [eq. (6)]. 2c′ reacts with 3c to give the alcohol CH3C[(CH3)2P(O)]2OH (5c). With stoichiometric amounts of water 3a, b, d - f are hydrolyzed to the corresponding alcohols RC[R′R″P(O)]2 OH (5a, b, d - f), which isomerize with the exception of 5a to the phosphinates RC[R′R″P(O)][OP(O)R′R″]H (6b - f) [eqs. (7a, b)].
    Notes: Die Acylphosphanoxide RC(O)P(O)R′R″ (3) erhält man im Falle von 3a - e durch Oxidation der Acylphosphane RC(O)PR′R″ (1a - e) mit rigoros getrocknetem Sauerstoff. 3c - e bilden sich auch aus den Anhydriden (RCO)2O (R = CH3, CF3) und Phosphanoxiden XP(O)R′R″ (2c′, d′). 3f entsteht nur aus CIPPh2 und Ameisensäure [Gln. (2a - c)]:3d, e dimerisieren zu den Phosphinaten RC[Ph2P(O)][OP(O)Ph2]C(O)R (4d, e) [Gl. (3)]. Beim Erhitzen eliminiert 3e mit ClRh(PPh3)3 CO unter Bildung von C2F6 und [Ph2P(O)—]2 [Gl. (4)]. Während 3a - e bei der Thermolyse die Ketene X2C2O(X = H, F) und die Phosphanoxide 2a′-e′ liefern [Gl. (5)], gibt 3f CO und 2d′ [Gl. (6)]. 2c′ und 3c reagieren zum Alkohol CH3C[(CH3)2P(O)]2OH(5c). Mit stöchiometrischen Mengen Wasser hydrolysieren 3a, b, d - f zu den entsprechenden Alkoholen RC[R′R″(O)]2 OH (5a, b, d - f), welche sich mit Ausnahme von 5a in die Phosphinate RC[R′R″P(O)][OP(O)R′R″]H (6b - f) isomerisieren [Gln. (7a, b)].
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    Berichte der deutschen chemischen Gesellschaft 112 (1979) 
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    Keywords: Chemistry ; Inorganic Chemistry
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 781-792 
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    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Heterocyclic Seven-membered Ring Compounds, XXII. Synthesis and Thermolysis of Substituted 4-Phenyl-l -benzothiepin 1-Oxides4-Phenyl-l-benzothiepin l-oxides 3a and b have been prepared as well via the benzothiepinone 1-oxide 2 as by direct oxidation of the parent 1-benzothiepins 6a and b. The synthesis of 3c and d was only accomplished by the second way. Further oxidation of 3a-d yielded the thermally stable dioxides 4a-d. Thermolysis of 3a-d produced the corresponding naphthalenes 5a-d by elimination of SO. The rates of the reaction 3→5 have been estimated for one temperature each.
    Notes: Die 4-Phenyl-l-benzothiepin-l-oxide 3a und b wurden sowohl über das Benzothiepinon-1-oxid 2 als auch durch direkte Oxidation der entsprechenden 4-Phenyl- 1-benzothiepine 6a und b dargestellt. Die Synthese von 3c und d erfolgte nur auf dem zweiten Weg. Weiteroxidation von 3a-d führte zu den thermisch stabilen Dioxiden 4a-d. Die Thermolyse von 3a-d lieferte unter Abspaltung von SO die entsprechenden Naphthaline 5a-d. Die Geschwindigkeitskonstanten der Reaktion 3→5 wurden für je eine Temperatur bestimmt.
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 883-889 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Significance of Diene-1,4-Distance on the Reactivity in Diels-Alder ReactionsThe reactivity of cyclopentadiene and di-exo-methylene compounds in Diels-Alder reactions is investigated using the frontier molecular orbital method. It is shown that besides the HOMO-LUMO energy difference the diene 1,4-distance plays an important part for the rate of reaction. The shorter this distance is the higher becomes the reactivity. Experimentally this is shown by the rates of reaction of tetracyanoethylene and maleic anhydride with cyclopentadiene and di-exo-methylene compounds 2-6. The 1,4-distance of the latter is known from force field calculations. 1,4-Distance and log k2 exhibit a linear relationship which is supported by theoretical considerations.
    Notes: Die Reaktivität von Cyclopentadien und cis-fixierten Di-exo-methylenverbindungen in Diels-Alder-Reaktionen wird im Rahmen des Grenzorbitalmodells untersucht. Es wird gezeigt, daß neben der Energiedifferenz der dominanten Grenzorbitalwechselwirkung auch der Dien-1,4-Abstand eine wichtige Funktion besitzt. Je kürzer dieser ist, umso reaktiver ist das Dien. Dies zeigt die Kinetik der Umsetzung von Tetracyanethylen und Maleinsäureanhydrid mit Cyclopentadien und den Di-exo-methylenverbindungen 2-6, deren 1,4-Abstand auf Grund von Kraftfeldrechnungen bekannt ist. Zwischen 1,4-Abstand des Diens und log k2 der Cycloaddition besteht ein linearer Zusammenhang, der sich theoretisch begründen läßt.
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1267-1271 
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    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cyclopentadienide Syntheses with Iodonium Ylides: Cyclopentadienides with Sulfur, Selenium, Phosphorus, and Arsenic as Onium CenterThe aryliodonio-cyclopentadienides 1 react with thioethers or diphenyl selenide at temperatures of 65 - 140°C to give the corresponding sulfonio- or selenonio-cyclopentadienides 2. Thioureas yield the isothiuronium betaines 4. The reactions of 1 with triphenylphosphane and -arsane to the phosphonio- and arsonio-cyclopentadienides 6 require temperatures of 140 - 150°C and catalysis by Cu compounds.
    Notes: Die Aryliodonio-cyclopentadienide 1 reagieren mit Thioethern oder Diphenylselenid bei Temperaturen von 65-140°C zu den entsprechenden Sulfonio- und Selenonio-cyclopentadieniden 2. Thioharnstoffe ergeben die Isothiuronium-Betaine 4. Die Reaktionen von 1 mit Triphenylphosphan und -arsan zu den Phosphonio- und Arsonio-cyclopentadieniden 6 benötigen Temperaturen von 140-150°C und Katalyse durch Cu-Verbindungen.
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1288-1296 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Decomposition Products of Imino-Δ3 1,2,4-thiadiazolinesImino-Δ3-1,2,4-thiadiazolines (2) are often instable, even at ambient temperature, especially those with R′ = alkyl or H. In case of 2, R = aryl, R′ = alkyl, two molecules combine with loss of one atom sulfur to yield the thiadiazolidines 3. The latter can be prepared alternatively from 2 and imidoylcarbodiimide or from sulfur and imidoylcarbodiimide. The decomposition of 2, R = phenyl. R′ = H, afforded the N-cyanobenzamidine 9b via an unknown red intermediate. From experiments and comparisons it is deduced that the possibility of fragmentation into sulfur and an acyl heterocumulene is a prerequisite for an easy decomposition of such a kind of molecules.
    Notes: Imino-Δ3-1,2,4-thiadiazoline (2) sind häufig schon bei Raumtemperatur instabil, besonders solche mit R′ = Alkyl oder H. Im Falle der Verbindungen 2, R = Aryl, R′ = Alkyl, vereinigen sich zwei Moleküle unter Austritt von einem Atom Schwefel zu den Thiadiazolidinen 3. Letztere können gezielt auch aus 2 und Imidoylcarbodiimiden oder aus Schwefel und Imidoylcarbodiimid hergestellt werden. Der Zerfall von 2, R = Phenyl, R′ = H, liefert über eine unbekannte rote Zwischenverbindung das N-Cyanbenzamidin 9b. Aus den Versuchen und Vergleichen wird abgeleitet, daß. Fragmentierbarkeit derartiger Moleküle in Schwefel und ein Acyl-heterocumulen Voraussetzung für den leichten Zerfall sind.
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1304-1315 
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    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Reactivity of Silicon Transition Metal Complexes, XII. Double Dicarbonyl(cyclopentadienyl)iron-substituted SilanesThe transition metal-substituted silanes [C5H5(CO)2Fe]2SiHR (R = CH3, Cl) (1, 2) are obtained via metallation of C5H5(CO)2Fe—SiHRCl with [C5H5(CO)2Fe]Na in cyclohexane. 1 is also formed together with C5H5(CO)2Fe—SiH2CH3 (3) by reaction of C5H5(CO)2Fe—SiH(CH3)Cl with sodium amalgam. CCl4 rapidly converts 1 and 2 to the chlorinated derivatives 4 and 5, which further react with AgBF4 to give the fluorosilyl complexes [C5H5(CO)2Fe]2SiFCH3 (6) and [C5H5(CO)2Fe]2SiF2 (8). The structure of the bimetallated silanes is determined by means of IR, NMR (1H, 13C, 19F, 29Si) and mass spectroscopy.
    Notes: Die übergangsmetall-substituierten Silane [C5H5(CO)2Fe]2SiHR (R = CH3, Cl) (I, 2) werden durch Metallierung von C5H5(CO)2Fe—SiHRCl mit [C5H5(CO)2Fe]Na in Cyclohexan erhalten. 1 bildet sich außerdem zusammen mit C5H5(CO)2Fe-SiH2CH3 (3) bei der Umsetzung von C5H5(CO)2Fe — SiH(CH3)Cl mit Natriumamalgam. CCl4 überführt 1 und 2 rasch in die chlorierten Abkömmlinge 4 und 5, die mit AgBF4 weiter zu den Fluorsilylkomplexen [C5H5(CO)2Fe]2SiFCH3 (6) und [C5H5(CO)2Fe]2SiF2 (8) reagieren. Die Struktur der bimetallierten Silane wird mit Hilfe von IR-, NMR (1H, 13C, 19F, 29Si)- und Massenspektroskopie bestimmt.
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  • 73
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1320-1328 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Transition Metal Carbyne Complexes, XLV. Cyclopentenylcarbene and -carbyne Metal Complexes of Chromium and TungstenThe cyclopentenylcarbene and-carbyne complexes (CO)5MC(OC2H5)(C5H7)(M = Cr. Mo. W) (1a-c) and trans-X(CO)4M≡CC5H7 (M = Cr, W; X = Cl, Br, I) (2a-e) are introduced as easily accessible, vinyl-substituted derivatives of this class of compounds. Complete characterization is achieved. An X-ray analysis of 2b rendered information about the influence of the carbon-carbon double bond of the cyclopentenyl group in conjugation to a metal-carbon triple bond.
    Notes: Mit den Cyclopentenylcarben- und -carbin-Komplexen (CO)5M C(OC2H5)(C5H7) (M = Cr, Mo, W) (1a-c) und trans-X(CO)4M≡CC 5H7 (M = Cr, W; X = Cl, Br, I) (2a-e) werden leicht zugängliche vinylsubstituierte Vertreter dieser Verbindungsklasse beschrieben und vollständig charakterisiert. Eine Röntgenstrukturbestimmung von 2b gab Aufschluß über den Einfluß der in Konjugation zur Metall-Kohlenstoff-Dreifachbindung stehenden C = C-Doppelbindung des Cyclopentenylrestes.
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  • 74
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1348-1358 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Electrophilic Aromatic Substitution Reactions with Protonated 1,3-Diazines, II. Preparation and Properties of 4-Aryl-substituted 3,4-Dihydroquinazoline DerivativesIn the presence of trifluoroacetic acid, quinazoline and 2-methylquinazoline react with a great variety of aromatic compounds to form 4-aryl-substituted 3,4-dihydroquinazolinium salts, e. g. 2, 3. From those, the dihydro bases 4 can be obtained which are readily oxidized to 4-aryl-substituted quinazolines 5, 6. Highly reactive compounds like indole are treated in formic acid or acetic acid, for better results. Also, some CH-acidic compounds react with quinazoline in trifluoroacetic acid.
    Notes: Bei Gegenwart von Trifluoressigsäure (TFE) reagieren Chinazolin und 2-Methylchinazolin mit einem weiten Spektrum aromatischer Verbindungen zu stabilen 4-arylsubstituierten 3,4-Dihydro-chinazoliniumsalzen, z. B. 2, 3, aus denen sich die zugrunde liegende Dihydrobase 4 erhalten läßt, die ihrerseits zu 4-arylsubstituierten Chinazolinen 5, 6 oxidiert werden kann. Im Fall besonders reaktiver Aromaten (z. B. Indol) läßt sich TFE vorteilhaft durch Eisessig oder Ameisensäure ersetzen. Auch eine Reihe CH-acider Verbindungen reagiert in TFE mit Chinazolin.
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  • 75
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1365-1371 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation and Structure of a Novel Spirobicyclic Phosphorane with λ3P-λ5P BondBy the reaction of [Si(CH3)3] (3-CF3C6H4) NC(O)NCH3 [Si(CH3)3] (1) with C6F5PCL2 the first λ3P-λ5P coordinated compound (2) is obtained. The structure was established by X-ray analysis. The λ3-phosphorus adopts an equatorial position in the larger ring of a spirobicyclic phosphorane which contains one four- and one five-membered ring. The coordination at the λ5-phosphorus displays a 21% distortion from an idealised trigonal bipyramid toward a square pyramidal geometry. The very different axial P—N bond lengths of 186.7 (3) and 174.3 (2) pm in the four and five-membered rings, respectively, are indicative of a significant degree of ring strain in the four and five-membered ring. The P—P bond length of 219.5 pm is slightly shorter than that which has been observed in diphosphanes with the coordination number 3.
    Notes: Durch Reaktion von [Si(CH3)3](3CF3C6H4)NC(O)NCH3[Si(CH3)3] (1) mit C6F5PCI2 konnte die erste Δ3P-λ5P-koordinierte Verbindung (2) erhalten werden. Die Struktur wurde durch eine Röntgenanalyse belegt. Der λ3- Phosphor nimmt eine äquatoriale Position im größeren Ring eines spirobicyclischen Phosphorans mit einem vier- und einem fünfgliedrigen Ring ein. Die Koordination am λ5- Phosphor zeigt eine Verzerrung von 21% von einer idealisierten trigonalen Bipyramide in Richtung einer quadratisch-pyramidalen Geometrie. Die sehr verschiedenen axialen P—N-Bindungsabstände von 186.7(3) und 1743.3(2) pm in den vier-bzw. fünfgliedrigen Ringen weisen auf eine erhebliche Ringspannung im Vierring hin. Die P—P-Bindungslänge ist mit 219.5 pm geringfügig kürzer als sie in Diphosphanen der Koordinationszahl 3 gefunden wird.
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  • 76
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1392-1399 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Ligand Structure and Complexation, XXXVII. Three-Armed Multidonor Neutral Ligands - Synthesis, Complex Formation, and Cation SelectivityThe long-chain multidonor tripodand molecules 2a-f, 3a-e, 4 and the lipophilic analogue substances 5-7 have been synthesized. Crystalline 1:1 complexes with alkali and alkaline earth metal salts have been isolated. The complex stability constants depend on the ligand topology. The tripodand 2 f with quinoline terminal groups shows the highest constant with Ba2⊕ ions (log Ks = 4; table 1).
    Notes: Die langkettigen, multizähnigen Tripodanden 2a-f, 3a-e, 4 und die lipophilen Analoga 5-7 wurden synthetisiert. Kristalline 1:1-Komplexe mit Alkali- und Erdalkalimetallsalzen wurden isoliert. Die Komplexstabilitätskonstanten hängen von der Ligandtopologie ab. Der Tripodand 2 f mit Chinolin-Endgruppen ergibt mit Barium-Ionen die höchste Konstante (log Ks = 4: Tab 1).
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  • 77
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1410-1419 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Addition of Aldehydes to Activated Double Bonds, XX. Syntheses of Unsymmetrical 1,4,7-TriketonesThiazolium salt catalysed additions of aldehydes to vinyl diketones (1-4, 10-12) lead to unsymmetrical 1,4,7-triketones (13-26). The vinyl diketones were obtained by addition of 2-formylnorbornene to alkyl vinyl ketones (30-32) followed by pyrolysis, the latter by the reaction of 2-cyanonorbornene with alkylmagnesium halides followed by hydrolysis and pyrolysis.
    Notes: Thiazoliumsalz-katalysierte Additionen von Aldehyden an Vinyldiketone (1-4, 10-12) führen zu unsymmetrischen 1,4,7-Triketonen (13-26). Die Vinyldiketone entstehen durch Addition von Norbornen-2-carbaldehyd an Alkylvinylketone und nachfolgende Pyrolyse. Die Alkylvinylketone (30 - 32) werden durch Reaktion des Norbornen-2-carbonitrils mit Alkylmagnesiumhalogeniden nach Hydrolyse und Pyrolyse erhalten.
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  • 78
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1420-1439 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Applications of Magnesium Thioacrolein Dianions to the Synthesis of Sulfur-free Compounds (Vinyl- and Divinylepoxides, Acylcyclopentenes)Doubly lithiated allyl (la) and methallylmercaptan and MgBr 2. etherate furnish reagents (cf. lb) which add to aldehydes and ketones, including α,β-unsaturated ones, to give the α-1,2-products 2-5 after methylation (see tables 1 and 2). The isolated hydroxythioethers contain less than 10% γ-adducts (cf. A in table 1); with enones no Michael-addition occurs; if there are two centers of chirality in 2 - 5, diastereomeric mixtures are formed. - With CH3I or Meerwein reagent the hydroxysulfonium salts G (OH instead of O⊖;) are generated which give E/Z mixtures of vinyl and divinyl oxiranes 6 and 7, respectively, upon treatment with aqueous base in a two-phase system. - Oxide-Cope rearrangement of the potassium alkoxides of the 1,5-hexadienes 3, 5 in THF, HMPT, or mixtures of the two solvents produces ketoaldehyde thioenol ethers 8 in good yields (tables 3 and 4). The α- and γ-1,2-adducts (3d, 10) rearrange with high constitutional and stereochemical selectivity to the ketones (8b, 11), see scheme 1. This provides evidence for a pericyclic rather than ionic (dissociation/recombination) mechanism of the oxide-Cope rearrangement of the alkoxides 3, 5 (O⊖ instead of OH). - Hydrolysis of the products 8 of rearrangement and aldol ring closure leads to cyclopentenyl ketones 14 in modest overall yields. For the thioenol ether hydrolysis a two step procedure (8 → 13 → 12) is recommended. - Scheme 2 demonstrates the synthetic equivalence of the organometallic reagent l b with allylidene and propionaldehyde d3-synthon.
    Notes: Die Magnesiumderivate des Thioacrolein-Dianions (lb) und des doppelt deprotonierten Methallylmercaptans werden aus den entsprechenden Lithioverbindungen und Magnesiumbromid-Etherat erhalten und reagieren mit normalen und α,β-ungesättigten Aldehyden und Ketonen zu α - 1,2-Produkten 2 - 5 (nach der Methylierung), siehe Tab. 1 und 2. - Aus den Diastereomerengemischen 2, 3 entstehen durch, S-Methylierung und Eliminierung E/Z-isomere Vinyl-(6) und Divinyloxirane (7). - Oxid-Cope-Umlagerung der Methylthio-hexadienole 3, 5 mit Kaliumhydrid in THF oder THF/HMPT führt zu Thioenolethern 8 von 6-Ketoaldehyden (s. Tab. 3 und 4). Durch die in Schema 1 gezeigten Versuche wird bewiesen, daß die Umlagerung konstitutions- und stereoselektiv verläuft, also nicht über äquilibrierende Dissoziation/Rekombination. - Über die Dicarbonylverbindungen 12 werden aus 8a - c die Cyclopentenylketone 14a - c hergestellt. Zur Hydrolyse von Thioenolethern wird ein zweistufiges Verfahren (Mercaptanaddition zum Thio-acetal und dessen HgII-Spaltung) empfohlen (8 → 13 → 12). - In Schema 2 ist die Syntheseäquivalenz des Organometallreagenz lb mit Allyliden und Propionaldehyd-d3-Synthon als Zusammenfassung der hier beschriebenen Umsetzungen verdeutlicht.
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1585-1594 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Mesoionic Six-membered Heterocycles, XI. Synthesis and Reactions of Mesoionic 1,3-OxazinesThe reaction of (chloroformyl) ketenes 1 with cyclic amides such as 2-pyridone (2) and 2-quinolones (8) leads to bicyclic mesoionic oxazines (3 and 9). With phenyl isocyanate these compounds are converted into pyrimidine betaines (6 and 10) by 1, 4-dipolar cycloaddition and elimination of CO2 With acetylenedicarboxylate 3 yields the quinolizinonedicarboxylate 7. The more unstable monocyclic oxazine betaines 13 are formed from N-substituted amides 12 and 1 in the presence of triethylamine. Higher reaction temperature leads by rearrangement to the isomeric quinolinedione 15. However, 2-phenylacetamide (17) as an aliphatic N-unsubstituted amide gives the oxazinone 18.
    Notes: Die Reaktion der (Chlorcarbonyl) ketene 1 mit cyclischen Säureamiden wie 2-Pyridon (2) und 2 Chinolonen (8) führt zu bicyclischen mesoionischen Oxazinen (3 und 9). Diese setzen sich mit Phenylisocyanat unter 1,4-dipolarer Cycloaddition und CO2 - Eliminierung zu den Pyrimidin-Betainen 6 und 10 um, Mit Acetylendicarbonsäureester reagiert 3 zum Chinolizinondicarbonsäureester. 7. Die instabileren monocyclischen Oxazin- Betaine 13 werden aus N - substituierten aromatischen Säureamiden 12 und 1 unter Zusatz von Triethylamin erhalten. Höhere Reaktionstemperaturen führen dagegen unter Umlagerung zum isomeren Chinolindion 15. 2-Phenylacetamid (17) als aliphatisches N-unsubstituiertes Säureamid gibt das Oxazinon 18.
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1595-1605 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reaction of Metal and Metalloid Compounds with Polyfunctional Molecules, XX. Reactions of N-(Trimethylsilyl)carboxamides with Dihalogenoorganylboranes and Trihalogenoboranes2,2,2-Trihalogeno-N-(trimethylsilyl)acetamides react with trichloroborane, tribromoborane, or dihalogenoorganylboranes to give the ring system of 1-oxa-3-azonia-5-aza-2-borata-3,5-cyclohexadiene (1-6). Trifluoroborane reacts with 2,2,2-trifluoro-N-(trimethylsilyl)acetamide to yield the trifluoroborane adduct 7 of trifluoroacetamide. The reaction of 2-chloro-N-(trimethylsilyl)acetamide with butyldichloroborane leads to the formation of the boryl chloroacetimidate 8 Analogous compounds are also obtained by substitution reactions of the chlorine atom in 3 with AgCN and NaN3 (→9, 10) or by the reaction of lithiated 2,2,2-trifluoro-N-(trimethylsilyl)acetamide with dihalogenoorganylboranes (→14, 15). Cleavage of both Si—N bonds in l-oxa-3,5-diaza-2,4-disila-5-cyclohexene 11 by dihalogenoorganylboranes leads to the corresponding 1-oxa-3,5-disila-2,4-dibora-5-cyclohexenes (12, 13). The 1H. 11B, and 19F NMR, Mass and 1R spectra are reported.
    Notes: Läßt man 2,2,2-Trihalogen-N-(trimethylsilyl)acetamide mit Trichlorboran. Tribromboran oder Dihalogenorganylboranen reagieren, So erhält man das Ringsystem des 1-Oxa-3-azonia-5-aza-2-borata-3,5-cyclohexadiens (1-6). Bei der Umsetzung von 2,2,2-Trifluor-N-(trimethylsilyl)acetamid mit Trifluorboran entsteht das Addukt 7 aus Trifluoracetamid und Trifluorboran. Die Reaktion von 2-Chlor-N-(trimethylsilyl)acetamid mit Butyldichlorboran ergibt den Chloracetimidsäure-borylester 8. Dazu analoge Verbindungen werden erhalten, wenn man in 3 das Chlor mit AgCN oder NaN3 reagieren läßt (→9, 10) oder lithiiertes 2,2,2-Trifluor-N-(Trimethylsilyl)-acetamid mit Dihalogenorganylboranen umsetzt(→14, 15). Durch Spaltung der beiden Si—N-Bindungen im 1-Oxa-3,5-diaza-2,4-disila-5-cyclohexen 11 durch Dihalogenorganylborane entstehen die entsprechenden 1-Oxa-3,5-diaza-2,4-dibora-5-cyclohexen-Verbindungen (12, 13). Die Verbindungen werden analytisch und spektroskopisch (NMR: 1H. 11B. 19F: MS: IR) charakterisiert.
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1626-1634 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stereochemistry of the Metal-Metal Bond. The Structures of three Complexes of the Type [L2M—PR2]2The molecular structures of the complexes [(NO)2Fe—P(C6H5)2]2 (2), and [CO(NO)Co—P(C6H5)2]2 (4) were determined crystallographically. Together with literature data they allow the discussion of the metal-metal bonding in two series of complexes. In the series [L2M P(C6H5)2]2 with L2M=(NO)2Fe, CO(NO)2Co, (CO)2Ni (1,4,5) the metal-metal-bond lengths are controlled by the electronic influence of the ligands L. In the series [(NO)2Fe—PR2]2 with R=C6H5, CH3, CF3 (1,2,3) the variation of the phosphorus substituents generates only minor changes of the molecular framework.
    Notes: Die Molekülstrukturen der Komplexe [(NO)2Fe—P(C6H5)2]2 (1), [(NO) 2Fe—P(CH3)2]2 (2) und [CO(NO)Co—P(C6H5)2]2 (4) wurden kristallographisch bestimmt. Sie erlauben zusammen mit Literaturangaben die Diskussion der Metall-Metall-Bindung in zwei Komplexreihen. In der Reihe [L2M—P(C6H5)2]2 mit L2M=(NO) 2Fe, CO(NO)Co, (CO) 2Ni (1,4,5) steuert der elektronische Einfluß der Liganden L die Metall-Metall-Bindungslängen. In der Reihe [NO) 2Fe—PR2]2mit R=C6 H5, CH3, CF3 (1,2,3) bewirkt die Variation der Phosphorsubstituenten R nur unwesentliche Veränderungen des Molekülgerüstes.
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1660-1669 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Aminobenzenes, XV. Halo and Pseudohalo σ-Complexes of Symmetrical Tris(dialkylamino)benzenes - Synthesis and Characterization1,3,5-Tris(dialkylamino)benzenes 1 react with halides or dirhodane in inert solvents at low temperatures to give, in part isolable, cationic intermediates 2 (σ-complexes) of electrophilic aromatic substitution. Treatment of compounds 2 with base produces halo benzenes 4, reacidification of 4 gives rise to the identical σ-complexes 2. The stability of complexes 2 depends upon the different mesomeric stabilization by the various dialkylamino substituents.
    Notes: 1,3,5-Tris(dialkylamino)benzole 1 bilden mit Halogenen und Dirhodan in inerten Lösungsmitteln bei tiefen Temperaturen die zum Teil isolierbaren kationischen Zwischenverbindungen 2 (σ-Komplexe) der elektrophilen Aromatensubstitution. Mit Basen entstehen aus 2 durch Deprotonierung die Halogenbenzole 4, die mit Säuren wiederum die identischen σ-Komplexe 2 bilden. Die Stabilität der Komplexe 2 hängt von der unterschiedlichen Mesomeriestabilisierung durch die verschiedenen Dialkylaminosubstituenten ab.
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1670-1676 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Halogenation of Enamines  -  Synthesis of β-Halo-immonium HalidesEnamines 4-6 react with halides in diethylether under exclusion of oxygene and moisture at -78°C to give the isolable β-halo-immonium halides 7-9, 13-15, and 19 in good yields. Acid hydrolysis leads to the α-halo ketones 10-12, 16-18, and 20.
    Notes: Die Enamine 4-6 bilden mit Halogenen in Diethylether bei -78°C unter Luft- und Feuchtigkeitsausschluß in sehr guter Ausbeute die isolierbaren β-Halogen-iminium-halogenide 7-9, 13-15 und 19. Die saure Hydrolyse führt zu den α-Halogenketone 10-12, 16-18, und 20.
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1705-1711 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 3-O-Benzyl-D-ribose3-O-Benzyl-D-ribose (4) is synthesized from D-glucose and D-ribose via different routes; these methods were compared. For a characterization 4 is transformed into 3′-O-benzyl-adenosine (19). 1H NMR data of the synthesized compounds are compiled.
    Notes: Aus D-Glucose und aus D-Ribose wird in vergleichenden Untersuchungen auf verschiedenen Wegen 3-O-Benzyl-D-ribose (4) hergestellt. Zur Charakterisierung wird 4 in 3′-O-Benzyladenosin (19) übergeführt. 1H-NMR-Spektroskopische Daten der synthetisierten Verbindungen werden mitgeteilt.
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 423-426 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Rel. Configuration and Crystal Structure of a Bufadienolide AnalogueThe X-ray analysis of 4 surprisingly proved a cis substitution pattern within the five-membered ring. Furthermore a conformational similarity between 3 and 4 is shown.
    Notes: Die Röntgenstrukturanalyse am Perhydrostilben-α-Pyron 4 bringt den überraschenden Befund einer cis-Anordnung der Substituenten im Cyclopentanring. Im übrigen entspricht die Konformation des Moleküls weitgehend der Verbindung 3.
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 397-407 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of (±)-“Isoalbene”In an attempt to synthesize the natural compound „albene“ it was shown that this material does not possess structure 1. Actually 1 is produced via the Diels-Alder adduct 10, followed by hydrogenation to 11 and Thorpe-Ziegler ring closure of the third carbocyclic ring by means of dinitrile 19. The resulting symmetrical ketone 3 is transformed into the thioenolether 21 with phenylmethanthiol. Desulfurization with Raney nickel yields 2.6-dimethyl-endo-tricyclo[5.2.1.02,6]dec-3-ene (1). which is not identical with natural „albene“.
    Notes: Bei dem Versuch einer Totalsynthese des Naturstoffs „Alben“ zeigte sich, daß diesem nicht die Strukturformel 1 zukommen kann. Die Darstellung von 1 erfolgte auf dem Wege über das Diels-Alder-Addukt 10, Hydrierung zu 11 und Schließen des dritten carbocyclischen Ringes mit Hilfe des Dinitrils 19 und Thorpe-Ziegler-Verfahrensweise. Das solcherart zugängliche symmetrische Keton 3 ließ sich mit Phenylmethanthiol in den Thioenolether 21 überführen. Entschwefelung mit Raney-Nickel ergab 2,6-Dimethyl-endo-tricyclo[5.2.1.0:2,6]dec-3-en (l), das mit natürlichem „Alben“ nicht übereinstimmte.
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  • 87
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 408-422 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: First Total Synthesis of (-)-„Albene“By different routes the synthesis of (-)- „albene“ (2) is investigated. The tert. carbinol 8 is produced stereospecifically via 2 -norbornanone (5). Ionic cyclisation of the former leads to a chloroolefin the structure of which is presumably shown by 11. Starting with camphenilone, 14 and 16 served in vain for ring closure reactions. Finally, 20 yields the tricyclus 21, which upon Baeyer-Villiger oxidation surprisingly leads to the carboxylic acid 25 and to 22 as well. 25 yields 2 on oxidative decarboxylation. The synthesis is used to determine the absolute configuration of the natural compound 2 and furthermore proves an uncommon endo - selectivity for the Nametkin rearrangement.
    Notes: Unterschiedliche Wege zur Synthese von (-)-„Alben“ (2) werden untersucht. Über 2-Norbornanon (5) wird stereospezifisch das tert. Carbinol 8 gewonnen, dessen ionische Cyclisierung zu einem Chlorolefin der mutmaßlichen Struktur 11 führt. Ausgehend von Camphenilon wurden 14 und 16 vergeblich in eine Ringschlußreaktion eingesetzt. Schließlich liefert 20 den erwünschten Tricyclus 21. Baeyer-Villiger-Oxidation hieran ergibt neben 22 überraschenderweise die Carbonsäure 25, die bei der oxidativen Decarboxylierung 2 erbringt. Gleichzeitig führt die Synthese zur Aufklärung der absoluten Konfiguration des Naturstoffs 2 sowie zur Beobachtung einer ungewöhnlichen endo -Selektivität für die Nametkin - Umlagerung.
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  • 88
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 445-461 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Triazenium Salts  -  A New Class of CompoundsTriazenium ions (azaallyl ions) of type 5 are obtained by alkylation, especially in an intramolecular reaction, of triazenes trisubstituted by alkyl and/or aryl groups. The cations 5 are isolated as stable tetrafluoroborates, perchlorates or iodides. The salts are decomposed by bases whereby the cyclic typ 20 (n = 2) forms triazolium salts. The UV spectra of 5 exhibit strong influences of substituents and geometry. Triazenium salts are the simplest azacyanines and they absorb at longer wave lengths (50-80 nm) than the corresponding amidinium salts.
    Notes: Durch Alkyl- und/oder Arylreste trisubstituierte Triazene lassen sich, insbesonders intramolekular, zu Triazenium-Ionen (Triazaallyl-Kationen) vom Typ 5 alkylieren, die als stabile Tetrafluoroborate, Perchlorate oder Iodide isoliert werden. Basen zersetzen die Salze, wobei aus dem cyclischen Typ 20 (n = 2) Triazoliumsalze entstehen. Die UV-Spektren der Triazeniumsalze zeigen starke Einflüsse von Substituenten und Geometrie. Als einfachste Azacyanine absorbieren sie 50 - 80 nm längerwellig als die entsprechenden Amidiniumsalze.
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  • 89
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 468-479 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Azidocobalt(III) Chelate Complexes with IsocyanidesAzidochelatecobalt(III) complexes N3Co(chelate)B (la-e) [chelate = e. g. dianion of N,N′-o-phenylenebis(salicylidenimine), B = PPh3] react with organic isocyanides to give metal-carbon bonded tetrazolate complexes 3, 4. 2-Isocyanoethanol affords tetrazolato- (9, 10) or azido-oxazolidin-2-ylidene complexes (11), depending on the nature of the solvent, the trans-base B, and the chelate ligand. The mechanism of formation of C-coordinated tetrazoles from azido complexes and isonitriles is discussed.
    Notes: Azidochelatcobalt(III)-Verbindungen N3Co(chelat)B(la-e) [chelat = z. B. Dianion von N,N′-o-Phenylenbis(salicylidenimin), B = PPh3] setzen sich mit organischen Isocyaniden zu Tetrazolatokomplexen 3, 4 mit Cobalt-Kohlenstoff-Bindung um. Mit 2-Isocyanethanol entstehen in Abhängigkeit vom Lösungsmittel, der trans-ständigen Base B und dem Chelatliganden Tetrazolato-(9, 10) oder Azido-oxazolidin-2-yliden-Komplexe (11). Der Mechanismus der Bildung C-koordinierter Tetrazole aus Azidokomplexen und Isonitrilen wird diskutiert.
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  • 90
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 567-576 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Enantiomeric Pentatetraenes and their Thermic Racemization EnergiesPartial hydroboration of the racemic pentatetraene 4 with chiral di(3-pinanyl)borane (6) gives the olefins 7 and 8, and starting material with about 5% enrichment of one enantiomer of 4. Complete separation of the enantiomers of 4 is achieved by chromatography on microcrystalline peracetylated cellulose. ( + )-4 with [α]D22 = + 336.6° (c = 0.8; CHC1,3) most likely has (S)-configuration. The enantiomers 4 racemize thermally at 358 K with activation parameters of ΔH≠ = 109.4 ± 1 kJmol-1, ΔS≠ = -18 ± 5JK-1 mol-1. and ΔG≠ = 115.8 ± 0.1 kJmol-1, independent of the polarity of the solvent.
    Notes: Die partielle Hydroborierung des racemischen Pentatetraens 4 mit chiralem Di(3-pinanyl)boran (6) führt zu den Olefinen 7 und 8, wobei im zurückgewonnenen Ausgangsmaterial 5% eines Enantiomeren von 4 angereichert werden. Die vollständige Enantiomerentrennung von 4 gelingt durch Chromatographie an mikrokristalliner peracetylierter Cellulose. (+)-4, [α]D22 = + 336.6° (c = 0.8; CHC13), besitzt wahrscheinlich (S)-Konfiguration. Die thermische Racemisierung von 4 ist bei 358 K von der Polarität des Mediums unabhängig und ergibt ΔH≠ = 109.4 ± l kJmoI-1, ΔS≠ = -18 ± 5JK-1mol-1 und ΔG≠ = 115.8 ± 0.1 kJmol-1.
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  • 91
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1923-1925 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Pheromones, XXIV. Synthesis of the Sex Attractants (Z)-7-Dodecenyl Acetate and (Z)-7-Tetradecenyl Acetate(Z)-7-Dodecenyl acetate, the female sex pheromone of the Noctuid moth Trichoplusia ni, and (Z)-7-tetradecenyl acetate, the sex attractant of Amathes c-nigrum (Lepidoptera), are prepared by stereoselective Wittig olefination using the „silazide“ -technique.
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  • 92
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1948-1955 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses of α-BromoisothiocyanatesSecondary isothiocyanates (1j-q) and primary isothiocyanates R—CH2 - NCS with an activating group R (1f, g) react with N-bromosuccinimide (NBS) to form α-bromoisothiocyanates 2 in high yields. The not activated primary isothiocyanate 1c slowly forms the stable α,α-dibromoisothiocyanate 10. In the presence of β-hydrogens some of the α-bromoisothiocyanates 2 eliminate HBr spontaneously, and secondary products may be formed. The α-bromination of isothiocyanates is a radical reaction following a Goldfinger mechanism.
    Notes: Sekundäre Isothiocyanate (1j-q) und primäre Isothiocyanate R-CH2 - NCS mit einer aktivierenden Gruppe R (1f, g) lassen sich mit N-Bromsuccinimid (NBS) in hohen Ausbeuten zu den α-Bromisothiocyanaten 2 bromieren. Das nicht aktivierte Isothiocyanat 1c reagiert langsam zum stabilen α,α-Dibromisothiocyanat 10. Bei Anwesenheit von β-Wasserstoffatomen spalten die α-Bromisothiocyanate 2 zum Teil spontan HBr ab, und es entstehen Folgeprodukte. Die α-Bromierung der Isothiocyanate erfolgt radikalisch nach einem Goldfinger-Mechanismus.
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  • 93
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1956-1972 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of α-Bromoisothiocyanatesα-Bromoisothiocyanates 11.2) with a hydrogen in β-position eliminate HBr to form vinyl isothiocyanates (products 2, 3, 5). Water hydrolyzes 1 to carbonyl compounds (7a). Hard nucleophiles attack 1 at the α-C-atom with substitution of bromine (products 8-12), but soft nucleophiles add to the C-atom of the isothiocyanato group (products 14, 19). Compounds 1 react with bifunctional nucleophiles to heterocycles (e. g. products 16, 21). The chemical properties of the classes of compounds, part of which are new, e. g. the geminal diisothiocyanates 12, are examined. The alkylidene thiourea 14f shows hindered rotation around the amide-CS—N bond (ΔG≠394 = 82.8 kJmol-1) and around the C=N double bond (ΔG≠244 = 52.9 kJmol-1).
    Notes: α-Bromisothiocyanate 1 mit einem β-Wasserstoff spalten HBr zu Vinylisothiocyanaten ab (Produkte 2, 3, 5). Wasser hydrolysiert 1 zu Carbonylverbindungen (7a). Harte Nucleophile greifen 1 am α-C-Atom unter Substitution des Broms an (Produkte 8-12), weiche Nucleophile lagern sich dagegen an das C-Atom der Isothiocyanatgruppe an (Produkte 14, 19). Verbindungen 1 reagieren mit bifunktionellen Nucleophilen zu Heterocyclen (z. B. Produkte 16, 21). Die chemischen Eigenschaften der z. T. neuen Verbindungsklassen, z. B. der geminalen Diisothiocyanate 12, werden untersucht. Der Alkylidenthioharnstoff 14f zeigt behinderte Rotation um die Amid Cs—N-Bindung (ΔG≠394 = 82.8 kJmol-1) und um die C=N-Doppelbindung (ΔG≠244 = 52.9 kJmol-1).
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  • 94
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1981-1990 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Hydrazidines, III. Synthesis of 1,2,4,5-Tetrazino[3,2-a]isoindolesReaction of acetohydrazide hydrazone hydrochloride (1) with phthalaldehydic acid (5) yields 3-methyl-1,10b-dihydro-1,2,4,5-tetrazino[3,2-a]isoindol-6(4H)-one (8), which affords 1,2,4,5-tetrazino[3,2-a]isoindol-6(4H)-one (9a) by mild oxidation. 9a is also obtained by the reaction of 1 with the phthalic acid derivatives 6a, 7a, and 7b. Starting with 9a, the 1,2,4,5-tetrazino[3,2-a]isoindoles 12-15 are synthesized. Interaction of 1 and 3-nitrophthalic anhydride (6b) yields two isomeric nitro-1,2,4,5-tetrazino[3,2-a]isoindol-6(4H)-ones (9b,c). Oxidation of 9a or b with KMnO4 in methanol affords the 1,2,4,5-tetrazino 17a, b. Mild Oxidation of 9a with KMnO4 in water/trichloromethane yields a dimer (20), which dissociates in nitromethane into the radical 19.
    Notes: Durch Reaktion von Acetohydrazid-hydrazon-hydrochlorid (1) mit Phthaladehydsäure (5) wird 3-Methyl-1, 10b-dihydro-1,2,4,5-tetrazino[3,2-a]isoindol-6(4H)-on (8) erhalten das durch milde Oxidation in 3-Methyl-1,2,4,5-tetrazino[3,2-a]isoindol-6(4H)-on (9a) übergeführt wird. 9a entsteht auch aus 1 und den Phthalsäurederivaten 6a, 7a und 7b. Ausgehend von 9a werden die 1,2,4,5-Tetrazino[3,2-a]isoindole 12-15 synthetisiert. Aus 1 und 3-Nitrophthalsäureanhydrid (6b) werden zwei isomere Nitro-1,2,4,5-tetrazino[3,2-a]isoindol-6(4H)-one (9b, c) erhalten. Oxidation von 9a oder b mit KMnO 4 in Methanol ergibt die 1,2,4,5-Tetrazine 17a, b. Vorsichtige Oxidation von 9a mit KmnO4 in Wasser/Chloroform ergibt ein Dimeres (20), das in Nitromethan in das Radikal 19 dissoziiert.
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 2012-2021 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Bicyclo[2.1.1]hexanes from Tricyclo[3.1.0.02,6]hexanesThe novel tricyclo[3.1.0.02,6]hexane derivatives 3 and 4, being fused with a fife- and a sixmembered ring respectively, are prepared from benzvalene in several steps. They and their lower homologues 1 and 2, having a three- and fourmembered ring respectively, add thiophenol under conditions of a radical reaction to form smoothly one cyclobutylphenyl thioether (16-19) in each case. Therefrom the parent hydrocarbons (5-8) which contain the bicyclo[2.1.1]hexane skeleton, are obtained by means of reduction with lithium in ethylamine.
    Notes: Ausgehend von Benzvalen werden in mehreren Stufen die neuen Tricyclo[3.1.0.02,6]hexan-Derivate 3 und 4 mit anelliertem Fünf- bzw. Sechsring dargestellt. Sie und ihre niedrigeren Homologen 1 und 2 mit Drei- bzw. Vierring nehmen unter Bedingungen einer Radikalreaktion Thiophenol auf, wobei glatt jeweils ein Cyclobutylphenylthioether (16-19) gebildet wird. Mit Lithium in Ethylamin sind aus 16-19 die tricyclischen Stammkohlenwasserstoffe mit dem Bicyclo[2.1.1 ]hexan-Gerüst (5-8) erhältlich.
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  • 96
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Protonenresonanz-Untersuchugen zur Inversion am dreibindigen Stickstoffatom, 6. Präparative Trennungen enantiomerer Diaziridine durch Flüssigkeits-Chromatographie an Triacetylcellulose. Verfolgung der Racemisierungen mittels Polarimetrie und 1H-NMREnantiomere Diaziridine ließen sich durch Chromatographie an Triacetylcellulose anreichern. (-)-2, (+)-4 und (-)-4 wurden fast rein erhalten, wobei die enantiomeren Reinheiten (Tab. 1) mittels 1H-NMR in Gegenwart optisch aktiver Zusätze bestimmt wurden. Dasselbe Verfahren wurde im Hinblick auf die Verfolgung von Racemisierungen (Tab.2) erprobt, welche mit höherer Genauigkeit außerdem mittels Polarimetrie studiert wurden. Die Schwellen der Stickstoff-Inversion, welche die trans-Diaziridine 2 und 4 in cis-Zwischenstufen überführt, werden mit bekannten ΔG≠-Werten verglichen.
    Notes: Enantiomeric diaziridines have been partially separated by chromatography on triacetlycellulose. (-)-2, (+)-4, and (-)-4 were obtained almost pure, enantiomeric purities (Table 1) being measured by 1H NMR in the presence of optically active additives. The same procedure was tested for monitoring racemizations (Table 2) which were also studied, with higher accuracy, by polarimetry. The barriers to nitrogen inversion, converting the trans-diaziridines 2and4into cis-intermediates, are compared with known ΔG≠ values.
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 2062-2067 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Trimethylsilyl Cyanide  -  A Reagent for Umpolung, II. Nucleophilic Acylation of Aldehydes and Ketones with Anionic 1,4-O,O-Silyl ShiftThe anion 9, derived from O-(trimethylsilyl) benzaldehyde-cyanohydrin (8), adds quantitatively to aldehydes and ketones. The primary adduct 11, which can be trapped as 12 after short reaction times, rearranges with 1,4-0,0-silyl shift. By subsequent cyanide elimination acyloin silyl ethers 14 are formed. Hydrolysis of 14 yields 80-90% of acyloins 15.
    Notes: Das Anion 9 des O-(Trimethylsilyl)benzaldehyd-cyanhydrins (8) addiert sich quantitativ an Aldehyde und Ketone. Das Primäraddukt 11, nach kurzer Reaktionszeit als 12 faßbar, lagert sich unter 1,4-0,0-Silylgruppenwanderung und Cyanidabspaltung zu den Acyloin - trimethylsilylethern 14 um, aus denen durch Hydrolyse die Acyloine 15 mit 80-90% Ausbeute entstehen.
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  • 98
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 1,6-Anhydrofuranoses, IX. Selective Monotosylation of 1,6-Anhydro-α-D-galactofuranose. Synthesis and Structure Determination of 1,6: 3,5-Dianhydro-α-D-gulofuranoseReaction of 1,6-anhydro-α-D-galactofuranose (1a) with 1.7 mol ρ-toluenesulfonyl chloride gives a mixture of all possible tosylates, the 3-0-derivative 1f with than 40% isolated yield predominating. Cyclization of 1f yields 1,6:3,5-dianhydro-α-D-gulofuranose (2a) with 2,5,7-trioxatricyclo[4.2.1.03.8]nonane skeleton. the structure of it being determined by X-ray crystallography and discussed in comparison to the equally determind structure of 1,6-anhydro-α-L-gulofuranose (3a).
    Notes: Umsetzung von 1,6-Anhydro-α-D-galactofuranose (1a) mit 1.7 mol ρ-Toluolsulfonylchlorid liefert ein Gemisch aller denkbaren Tosylate, in dem das 3-0-Derivat 1fmit über 40% isolierter Ausbeute überwiegt. Dieses läßt sich zur 1,6:3,5-Dianhydro-α-D-gulofuranose (2a) mit 2,5,7-Trioxatricyclo[4.2.1.03.8] nonan-Gerüst cyclisieren, deren Struktur wie die der 1,6-Anhydro-α-L-gulofuranose (3a) durch Röntgenstrukturanalyse bestimmt und diskutiert wird.
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 2087-2094 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cyclopentadienylidenes, XV. Cyclohepta[c]pyrrole-6(2H)-thione, a Stable TropothioneCyclohepta[c]pyrrole-6(2H)-thiones (5) are synthesized in two ways from cyclohepta[c]pyrrole-6[2H]-ones (2). The thiones are characterized by reaction with methyl iodide, 9-diazo-1,8-diaza-fluorene (8), and diphenyldiazomethane (11), respectively. Dipole moments of 2 and 5 are reported, spectroscopic data of 5 and of some reaction products are discussed.
    Notes: Cyclohepta[c]pyrrol-6(2H)-one (2) lassen sich nach zwei Methoden in stabile Thioanaloge 5 überführen, die chemisch als Methoiodide 6 und durch Reaktion mit 9-Diazo-1,8-diazafluoren (8) bzw. Diphenyldiazomethan (11) charakterisiert werden können. Dipolmomente von 2 und 5 werden mitgeteilt, spektroskopische Daten von 5 und deren Folgeprodukte diskutiert.
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    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 2120-2144 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Deamination Reactions, 33. Reactions of Aliphatic Diazonium Ions with Lithium AzideThe reactions of aliphatic diazonium ions with lithium azide in methanol to give organic azides proceed by a variety of mechanisms. Azo coupling has been definitely established by means of 15N labels in the case of cyclopropane and alkenediazonium ions. The contribution of a pentazole to the coupling pathway is ca. 40% with cyclopropanediazonium ions, but less than 20% with alkenediazonium ions, as shown by a comparison of α- and β- 15N labeled diazonium ions. No coupling occurs with diazonium groups at sp3 hybridized carbons, including bicyclo[2.2.1]heptane-1-diazonium ions (2). Most of them produce alkyl azides by SN1 mechanisms; selectivities indicate some participation of azide ion in the extrusion of nitrogen from primary alkanediazonium ions. Whenever the diazo compounds generated by deprotonation of the diazonium ions are thermally labile, the carbenes thus produced also contribute to the formation of organic azides. Variations in product distribution, 15N content, and deuterium incorporation served to identify this novel mechanism.
    Notes: Die Reaktionen aliphatischer Diazonium-Ionen mit Lithiumazid in Methanol zu organischen Aziden verlaufen nach unterschiedlichen Mechanismen. Für Cyclopropan- und Alkendiazonium-Ionen wurde Azokupplung mit Hilfe von 15N-Markierung eindeutig nachgewiesen. Der Pentazol-Anteil an der Kupplungsreaktion beträgt ca. 40% bei Cyclopropandiazonium-Ionen, dagegen ≤ 20% bei Alkendiazonium-Ionen, wie aus dem Vergleich α- und β-15N-markierter Diazonium-Ionen hervorgeht. Diazoniumgruppen an sp3-hybridisiertem Kohlenstoff zeigen keine Kupplung, auch nicht Bicyclo[2.2.1]heptan-1-diazonium-Ionen (2). Aus ihnen entstehen Alkylazide meist nach einem SN1-Mechanismus; Selektivitätsuntersuchungen weisen auf die Beteiligung des Azid-Ions an der Stickstoffabspaltung aus primären Alkandiazonium-Ionen hin. Wenn die Deprotonierung der Diazonium-Ionen zu thermisch labilen Diazoverbindungen führt, tragen die so erzeugten Carbene ebenfalls zur Bildung organischer Azide bei. Veränderungen in der Produkt-verteilung, im 15N-Gehalt und im Deuterium-Einbau dienten zum Nachweis dieses neuartigen Mechanismus.
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