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  • Inorganic Chemistry  (765)
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  • 1975-1979  (1,797)
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  • 1978  (1,797)
  • 1
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    In:  J. Geophys., Berlin, Conseil de l'Europe, vol. 44, no. 31, pp. 511-523, pp. B04310, (ISBN: 0534351875, 2nd edition)
    Publication Date: 1978
    Keywords: Seismic arrays ; Broad-band ; Seismology ; Data analysis / ~ processing
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  • 2
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    In:  Bull. Seism. Soc. Am., Amsterdam, Schweizerbart'sche Verlagsbuchhandlung, vol. 68, no. 8, pp. 1265-1279, pp. L12S09, (ISSN 0016-8548, ISBN 3-510-50045-8)
    Publication Date: 1978
    Keywords: Seismology ; Earthquake precursor: prediction research ; Fore-shocks ; Earthquake ; Earthquake precursor: statistical anal. of seismicity ; BSSA
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  • 3
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    In:  Bull. Seism. Soc. Am., Tokyo, Tokyo University, vol. 68, no. 2, pp. 471-485, pp. 2265, (ISSN 0016-8548, ISBN 3-510-50045-8)
    Publication Date: 1978
    Keywords: Strong motions ; Seismology ; BSSA ; local Magnitude
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  • 4
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    In:  J. Geophys. Res., Tokyo, Tokyo University, vol. 83, no. 2, pp. 3427-3434, pp. 2265, (ISSN 0016-8548, ISBN 3-510-50045-8)
    Publication Date: 1978
    Keywords: Earthquake ; Seismology ; JGR
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  • 5
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    In:  Bull. Seism. Soc. Am., Basel, Elsevier Science Publishers, vol. 68, no. 8, pp. 1-29, pp. L15S20, (ISSN: 1340-4202)
    Publication Date: 1978
    Keywords: Teleseismic events ; Earthquake ; Source ; Seismology ; Source parameters ; BSSA
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  • 6
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    In:  Geophys. J. R. astr. Soc., Reykjavík, Icelandic Meteorological Office, Ministry for the Environment University of Iceland, vol. 52, no. 5, pp. 441-455, pp. TC1011, (ISSN 0016-8548, ISBN 3-510-50045-8)
    Publication Date: 1978
    Keywords: Seismology ; Data analysis / ~ processing ; Spectrum ; Spectral analysis ; Inhomogeneity ; GJRaS
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  • 7
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    In:  Nature, Tokyo, Tokyo University, vol. 271, no. 2, pp. 411-414, pp. 2265, (ISSN 0016-8548, ISBN 3-510-50045-8)
    Publication Date: 1978
    Keywords: Seismology ; Source parameters ; Magnitude ; Review article
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  • 8
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    In:  Geophys. J. R. astr. Soc., Luxembourg, Conseil de l'Europe, vol. 52, no. 3, pp. 503-524, pp. B04202, (ISSN: 1340-4202)
    Publication Date: 1978
    Keywords: Seismology ; Attenuation ; Frequency ; GJRaS
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  • 9
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    In:  J. Geophys., Warszawa, American Geophysical Union, vol. 44, no. 1+2, pp. 203-218, pp. L08304, (ISSN: 1340-4202)
    Publication Date: 1978
    Keywords: Fracture ; Fault plane solution, focal mechanism ; Source ; Earthquake ; Seismology ; Moment tensor ; EUROPROBE (Geol. and Geophys. in eastern Europe) ; Muller ; Stoeckel ; Stockel
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  • 10
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    In:  Bull. Seism. Soc. Am., New York, August, vol. 68, no. 1, pp. 501-512, pp. 1610, (ISSN: 1340-4202)
    Publication Date: 1978
    Keywords: Seismology ; Transfer function ; SRO ; Instruments ; Seismic networks ; BSSA
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  • 11
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    In:  Geophys. Res. Lett., Hannover, Conseil de l'Europe, vol. 5, no. 6, pp. 321-324, pp. L04301, (ISSN: 1340-4202)
    Publication Date: 1978
    Keywords: Crustal deformation (cf. Earthquake precursor: deformation or strain) ; Seismology ; Stress ; GRL
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  • 12
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    In:  Nature, Basel, Inst. f. Geophys., Ruhr-Univ. Bochum, vol. 275, no. 4, pp. 599-602, pp. L14311, (ISSN: 1340-4202)
    Publication Date: 1978
    Keywords: Seismology ; Stress ; silent ; red ; Source
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  • 13
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    In:  Geophys. J. R. astr. Soc., Leyden, Noordhoff International Publishing, vol. 52, no. B2, pp. 359-364, pp. B04306, (ISSN: 1340-4202)
    Publication Date: 1978
    Keywords: Seismology ; Moment tensor ; Source ; SModelling ; GJRaS
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  • 14
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    Bundesanstalt f. Geowissenschaften und Rohstoffe
    In:  Hannover, Bundesanstalt f. Geowissenschaften und Rohstoffe, vol. 113, no. XVI:, pp. 1-14, (ISBN 1-56670-263-3)
    Publication Date: 1978
    Keywords: Seismology ; Engineering geophys. ; Earthquake risk ; Earthquake hazard
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  • 15
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    In:  Geophys. J. R. astr. Soc., Amsterdam, Elsevier Scientific Publishing Company, vol. 52, no. 12, pp. 65-96, pp. 1390
    Publication Date: 1978
    Keywords: Seismology ; Fracture ; GJRaS
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  • 16
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    In:  Geophys. Res. Letters, Münster, 3, vol. 5, no. 6, pp. 1-4, pp. L23301, (ISBN: 0534351875, 2nd edition)
    Publication Date: 1978
    Keywords: Seismology ; Source ; Aftershocks ; Green's function ; GRL
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  • 17
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    In:  J. Geophys. Res., Luxembourg, EGS-Gauthier-Villars, vol. 83, no. 6717, pp. 5869-5882, pp. 2324
    Publication Date: 1978
    Keywords: Attenuation ; Absorption ; Scattering ; Seismology ; Earth rotation ; Earth tides ; Quality factor ; JGR
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  • 18
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    In:  Bull. Seism. Soc. Am., Luxembourg, Conseil de l'Europe, vol. 68, no. 8, pp. 283-300, pp. L15S17, (ISBN: 0-12-018847-3)
    Publication Date: 1978
    Keywords: Seismology ; Source parameters ; Fracture ; BSSA
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  • 19
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    In:  Bull. Seism. Soc. Am., Taipei, Elsevier, vol. 68, no. 3, pp. 49-79, pp. TC1002, (ISBN: 0-12-018847-3)
    Publication Date: 1978
    Keywords: Seismology ; Source ; Spectrum ; Scaling ; Nuclear explosion ; BSSA
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  • 20
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    In:  Tectonophys., Dordrecht, D. Reidel, vol. 51, no. 5, pp. T39-T46, pp. TC5003, (ISSN: 1340-4202)
    Publication Date: 1978
    Keywords: Seismology ; Energy (of earthquakes) ; Source parameters ; Magnitude ; FROTH ; (abstract)
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  • 21
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    In:  Bull. Seism. Soc. Am., Warszawa, EGS, vol. 68, no. 3, pp. 735-756, pp. L02611, (ISSN: 1340-4202)
    Publication Date: 1978
    Keywords: Seismology ; Filter- ; Auto-Regressive Moving Average-process ; Discrimination ; High frequency ... ; BSSA
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  • 22
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    Center for Acad. Publ. Japan
    In:  Bull., Open-File Rept., Earthquake Precursors, Tokyo, Center for Acad. Publ. Japan, vol. 65, no. 1, pp. 69-78, (ISBN 1-86239-165-3, vi + 330 pp.)
    Publication Date: 1978
    Keywords: Earthquake precursor: prediction research ; Seismology ; Project report/description ; Review article
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  • 23
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    In:  Vychislitel'naya Seismogogiya, Luxembourg, Conseil de l'Europe, vol. 11, no. B7, pp. 111-133, pp. 2131, (ISSN: 1340-4202)
    Publication Date: 1978
    Keywords: Seismology ; Inversion
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  • 24
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    In:  Bull. seism. Soc. Am., Washington, D.C., AGU, vol. 68, no. 1, pp. 907-922, pp. 2090, (ISSN: 1340-4202)
    Publication Date: 1978
    Keywords: Seismology ; Synthetic seismograms ; Surface waves ; NOModelling ; Layers ; Strong motions ; BSSA
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  • 25
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    In:  Bull. Earthq. Res. Inst. (Tokyo), Taipei, EGS, vol. 53, no. 12, pp. 1-48, pp. L12306, (ISSN: 1340-4202)
    Publication Date: 1978
    Keywords: Spectral analysis ; Seismology ; Scattering
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  • 26
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    Center for Akad. Publ. Japan
    In:  Professional Paper, Earthquake Precursors, Tokyo, Center for Akad. Publ. Japan, vol. 4, no. 231, pp. 243-250, (ISBN 1-4020-1729-4)
    Publication Date: 1978
    Keywords: Earthquake precursor: prediction research ; Earthquake precursor: statistical anal. of seismicity ; Seismology ; Earthquake ; Seismicity
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  • 27
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    Fakultät für Physik
    In:  Dissertation, Universität Karlsruhe, Fakultät für Physik, vol. 10, no. WS-693 7-83, pp. 235-239, (ISBN 3-933346-037)
    Publication Date: 1978
    Keywords: Location ; Seismology ; Velocity ; Hypocentral depth ; Earth model, also for more shallow analyses ! ; Velocity depth profile
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  • 28
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    In:  Seventh Annual IPA Convention, Atlanta, Soc. Explorat. Geophys., vol. C 560, 183 pp., no. 8, pp. 480-482, (ISBN 3-933346-037)
    Publication Date: 1978
    Keywords: Waves ; Seismology ; Wavelet processing
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  • 29
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    USGS, Open file Rep. 78-380 and Inst. Phys. du Globe, Univ. Paris VI, IPG No. 275
    In:  Proc. Conf. III, Fault Mechanics and its Relation to Earthquake Prediction, Nat. Earthq. Hazard Reduction Program, 1-3.12.1977, Hanscom Air Force Base, USGS, Open file Rep. 78-380 and Inst. Phys. du Globe, Univ. Paris VI, IPG No. 275, vol. C 560, 183 pp., no. PL-TR-91-2212(II), pp. 319-337, (ISBN 3-933346-037)
    Publication Date: 1978
    Keywords: Seismology ; Stress ; Earthquake precursor: prediction research ; seismic Moment ; Stress drop ; FROTH, ; FRUMMEL
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  • 30
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    U.S. Geol. Surv.
    In:  Open-File Report, Potsdam, U.S. Geol. Surv., vol. C 560, 183 pp., no. 78 (?), pp. 1448-1451, (ISBN 3-933346-037)
    Publication Date: 1978
    Keywords: Seismic networks ; Geothermics ; Seismology
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  • 31
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    Inst. f. Geophys., Ruhr-Univ. Bochum
    In:  Dissertation, Berichte Reihe A, Aachen, Inst. f. Geophys., Ruhr-Univ. Bochum, vol. 10, no. 6, pp. 429-433, (ISBN 3-933346-037)
    Publication Date: 1978
    Keywords: Seismology ; Seismic networks ; Location ; Induced seismicity ; Rock bursts (see also ERDSTOSS and GEBIRGSSCHLAG)
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  • 32
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    MIT Lincoln Lab.
    In:  Semiannual Technical Summary Report, Lexington, Mass., MIT Lincoln Lab., vol. 10, no. 87-437, pp. 9, 29-31, (ISBN 3-933346-037)
    Publication Date: 1978
    Keywords: Seismology ; PIC ; son ; SRO ; Broad-band ; Seismic networks
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  • 33
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    In:  Bull. Seism. Soc. Am., Zagreb, Conseil de l'Europe, vol. 68, no. 4, pp. 1095-1102, pp. L02307, (ISSN 0343-5164)
    Publication Date: 1978
    Keywords: Seismology ; Fault plane solution, focal mechanism ; Source parameters ; BSSA
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  • 34
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    Seismologischen Zentralobservatorium Gräfenberg
    In:  Berichte der seismologischen Observatorien in der Bundesrepublik Deutschland mit einem Katalog wichtiger Weltbeben, Oslo, Seismologischen Zentralobservatorium Gräfenberg, vol. 10, no. 421, pp. 1-24, (ISBN 3-933346-037)
    Publication Date: 1978
    Keywords: Earthquake catalog ; Germany ; Seismic networks ; Seismology
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  • 35
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    U. S. Geol. Surv.
    In:  Open-File Report, Hannover, U. S. Geol. Surv., vol. C 560, 183 pp., no. 78-694, pp. 1-113, (ISBN 3-933346-037)
    Publication Date: 1978
    Keywords: Seismology ; Location ; Hypocentral depth ; software ; USGS
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  • 36
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    Inst. f. Geophys., Univ.
    In:  Diplomarbeit, Hamburg, Inst. f. Geophys., Univ., vol. C 560, 183 pp., no. PL-TR-91-2130, pp. 1-113, (ISBN 3-933346-037)
    Publication Date: 1978
    Keywords: P-waves ; CRUST ; Seismology ; Seismic arrays ; Spectrum
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  • 37
    Electronic Resource
    Electronic Resource
    Springer
    Pure and applied geophysics 116 (1978), S. 1274-1283 
    ISSN: 1420-9136
    Keywords: Seismology ; Surface-wave dispersion ; Higher mode surface waves ; Italy, phase vel. of surface waves
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract A new method is presented for the determination of higher mode dispersion over small distances, using two stations. From an intermediate focus earthquake it has been possible to measure the dispersion of the first and second Rayleigh modes in the period range 25–35 sec and 25–70 sec respectively. Using the almost linear array of Italian long-period stations TRI, BLZ, OLB an estimate of the average errors is also made.
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  • 38
    Electronic Resource
    Electronic Resource
    Springer
    Pure and applied geophysics 116 (1978), S. 1299-1306 
    ISSN: 1420-9136
    Keywords: Seismology ; Rayleigh wave dispersion ; Phase velocity of Rayleigh waves ; German Dem. Rep., Rayleigh waves
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Summary The phase velocity curve of Rayleigh-waves is determined for a profile crossing the area of GDR from south to north. Two different methods of seismogram processing are used which are discussed in detail. The phase velocities found are checked for compatibility. An inversion of a common phase velocity curve is done by using hedgehog procedure.
    Type of Medium: Electronic Resource
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  • 39
    Electronic Resource
    Electronic Resource
    Springer
    Pure and applied geophysics 116 (1978), S. 1262-1273 
    ISSN: 1420-9136
    Keywords: Seismology ; African Rift ; P-wave velocity beneath Africa ; Upper mantle structure for Africa
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract AP-wave velocity model for the upper mantle beneath eastern and southern Africa is proposed. The top 250 km of the model is characterized by relatively low velocities similar to those deduced for the upper mantle beneath the western United States of America. At greater depths, the velocities gradually change to normal mantle values.
    Type of Medium: Electronic Resource
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  • 40
    Electronic Resource
    Electronic Resource
    Springer
    Pure and applied geophysics 116 (1978), S. 198-211 
    ISSN: 1420-9136
    Keywords: Seismology ; theoretical ; Cagniard's technique ; Elastic waves produced by shearing traction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The displacement produced in a semi-infinite, homogeneous, isotropic elastic medium by the application of shearing traction over a circular portion of the half-space has been evaluated in exact form by Cagniard's Technique (Cagniard, 1962;Gakenheimer andMiklowitz, 1969).
    Type of Medium: Electronic Resource
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  • 41
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978) 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 42
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1-12 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Determination of Activation Parameters of Spironorcaradiene-Spirocycloheptatriene Equilibria by Line Shape Analysis of 1H and 13C NMR SpectraLine shape analysis of 1H and 13C NMR spectra is used for the determination of activation parameters of the valence isomerization of substituted spironorcaradienes/spirocycloheptatrienes 5 ⇌ 6. Whereas the values obtained for the dibenzo-spironorcaradienes 5a, b are comparable with the data of simple norcaradiene derivatives, those of tetrachloro derivatives 5c, d show considerable differences.
    Notes: Die Linienformanalyse der 1H- und 13C-NMR-Spektren wird zur Bestimmung der Aktivierungsparameter der Valenzisomerisierung von verschieden substituierten Spironorcaradienen zu Spirocycloheptatrienen 5 ⇌ 6 herangezogen. Während die Aktivierungsparameter bei Dibenzospironorcaradienen 5a, b vergleichbar sind mit denen der einfachen Norcaradienderivate, treten bei den Daten der Tetrachlorderivate 5c, d erhebliche Abweichungen auf.
    Additional Material: 4 Ill.
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  • 43
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 42-55 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Allyl Radicals with Bicyclo[3.2.1]octane Skeleton, a Contribution to the Problem of Homoconjugative InteractionsThe ESR spectra of allyl radicals with bicyclo[3.2.1]octane skeleton were analyzed in order to investigate the possibility of nonbonding interactions in free radicals. The similarity of the spin density distribution in radicals 7 and 8 demonstrates that 7 has the character of a bicyclic allyl radical. There is no significant interaction between HOMO allyl and LUMO double bond in 7. The same is true for the radical having a fused benzene ring instead of the double bond.
    Notes: Radikale mit Bicyclo[3.2.1]octan-Gerüst wurden ESR-spektroskopisch untersucht, um Aussagen über nichtbindende Wechselwirkungen in Radikalen zu gewinnen. Die Ähnlichkeit der Spindichteverteilung in 7 und 8 zeigt, daß 7 den Charakter eines bicyclischen Allylradikals besitzt. Eine merkliche Wechselwirkung wischen HOMO-Allyl und LUMO-Doppelbindung in 7 existiert nicht. Gleiches gilt, wenn anstelle der Doppelbindung ein Benzolrest anelliert ist. Die experimentellen Befunde werden mit INDO-Rechnungen verglichen.
    Additional Material: 6 Ill.
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  • 44
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 56-64 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Mechanism of the Thermal Isomerisation of O-2-Butenyl O,O-Dimethyl Thiophosphate. Kinetic StudyThe thermal isomerisation of O-2-butenyl O,O-dimethyl thiophosphate (1b) (scheme 3) obeys first order rate law. Solvent polarity does not affect the parameters of activation, but influences a little the rate constants. The kinetic data and the observed “special” salt effect lead to the conclusion that the isomerisation proceeds by a dissociative mechanism. Ion pairs as intermediates are proposed.
    Notes: Die thermische Isomerisierung von Thiophosphorsäure-O-2-butenylester-O,O-dimethylester (1b) (Schema 3) verläuft nach einem Geschwindigkeitsgesetz 1. Ordnung. Die Polarität des Mediums beeinflußt nicht die Aktivierungsparameter und übt lediglich einen minimalen Einfluß auf die Geschwindigkeitskonstanten aus. Die kinetischen Daten und der festgestellte „spezielle“ Salzeffekt lassen den Schluß zu, daß diese Isomerisierung einem intramolekularen ionischen Mechanismus folgt. Als ionische Zwischenstufe werden Ionenpaare postuliert.
    Additional Material: 1 Ill.
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  • 45
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1210-1216 
    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 Phosphorus, 73: 1,2-Diphenyldiphosphane1,2-Diphenyldiphosphane (1) is formed, contrary to results given in the literature, by the reaction of KHPPh with 1,2-dibromoethane. Pure 1 is obtained by hydrolysis or alcoholysis of Me3Si(Ph)P-P(Ph)SiMe3 in the dark. It is stable at - 30°C. 1 disproportionates at room temperature to give PhPH2, higher homologues of the series H2[PPh]n, especially H2[PPh]3, and cyclic phenylphosphanes [PPh]n, mainly [PPh]5. These rearrangements are accelerated by light, phosphides, and strong acids and bases. With K(Ph)P—P(Ph)K, Me3Si(Ph)P—P(Ph)SiMe3, and P2Ph4 1 reacts to give the asymmetric diphosphanes K(Ph)P—P(Ph)H, Me3Si(Ph)P—P(Ph)H, and Ph2P—P(Ph)H, respectively. The NMR, IR, and Raman spectra are discussed.
    Notes: 1,2-Diphenyldiphosphan (1) wird - entgegen Literaturangaben - bei der Reaktion von KHPPh mit 1,2-Dibromethan gebildet. Reines 1 ist durch Hydrolyse oder Alkoholyse von Me3Si(Ph)P - P(Ph)SiMe3 unter Lichtausschluß erhältlich und bei - 30°C beständig. Es disproportioniert bei Raumtemperatur in PhPH2, höhere Homologe der Reihe H2[PPh]n  -  insbesondere H2[PPh]3 - und cyclische Phenylphosphane [PPh]n  -  vor allem [PPh]5. Diese Umlagerungen werden durch Licht, Phosphide sowie starke Säuren und Basen beschleunigt. Mit K(Ph)P—P(Ph)K, Me3Si(Ph)P—P(Ph)SiMe3 oder P2Ph4 reagiert 1 zu den unsymmetrischen Diphosphanen K(Ph)P—P(Ph)H, Me3Si(Ph)P—P(Ph)H bzw. Ph2P—P(Ph)H. Die NMR-, IR- und Raman-Spektren von 1 werden diskutiert.
    Additional Material: 1 Tab.
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  • 46
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1223-1227 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Organic Syntheses by Means of Transition Metal Complexes, 6: Synthesis of Ketenimines via Ketenimine Complexes, Isocyanide Carbene Addition and Ketenimine Carbene Rearrangement in Metal ComplexesTransition metal carbene complexes of the Fischer type, e. g. pentacarbonyl(methoxymethyl-carbene)chromium(0), add isocyanides to give ketenimine complexes (1). Ligand displacement by excess isocyanide affords ketenimines (3), which can be isolated in good yields. In contrast to free ketenimine, the nucleophilic attack on ketenimine coordinated to a metal occurs at the terminal carbon atom leading to carbene complexes. The structures of the ketenimine complexes of chromium (1) and tungsten (2), the product of isomerization (5)(2) of the chromium complex, and the products formed by addition of methanol or water (6 and 7, resp.)(2) are discussed, using 13C NMR data.
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    Berichte der deutschen chemischen Gesellschaft 111 (1978) 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 48
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1233-1238 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Polycyclic Compounds, X: A Facile Synthesis of (Partially Hydrogenated) Benz[a]anthracenes with Functional GroupsThe hexa- and decahydrobenz[a]anthracenes 3 and 5 are available in a one step synthesis by Diels-Alder reaction of the tetrahydrobenzo[b]furans 2 with 2,3-didehydronaphthalene (1) or with the naphthalene-endoxide 4. The interconversions 3 → 6, 7 and 8 and 5 → 9 show that many hydroxy- and oxosubstituted (partially hydrogenated) benz[a]anthracenes can be obtained from the primary adducts 3 and 5.
    Notes: Die Hexa- und Decahydrobenz[a]anthracene 3 und 5 sind in einem einstufigen Verfahren durch Diels-Alder-Reaktionen der Tetrahydrobenzo[b]furane 2 mit 2,3-Didehydronaphthalin (1) bzw. mit dem Naphthalin-endoxid 4 zugänglich. Die Reaktionsfolgen 3 → 6, 7 und 8 sowie 5 → 9 zeigen die vielfältigen Abwandlungsmöglichkeiten der Primäraddukte 3 und 5 zu hydroxy- und oxo-substituierten (partiell hydrierten) Benz[a]anthracenen auf.
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  • 49
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1253-1263 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Vinyl Cations, 26: Syntheses and Solvolyses of Vinyl FluoridesThe vinyl fluorides 5-8 were prepared by treatment of the corresponding olefins with BrF and subsequent dehydrobromination. The solvolysis reactions in various solvents were studied. The products and their rates of solvolysis measured under different conditions point to a vinyl cation mechanism of the solvolysis reactions.
    Notes: Die Vinylfluoride 5-8 wurden durch Umsetzung der entsprechenden Olefine mit BrF und sich anschließende Dehydrobromierung dargestellt und die Solvolysereaktionen in mehreren Lösungsmitteln untersucht. Die Reaktionsprodukte sowie die unter verschiedenen Bedingungen gemessenen Solvolysegeschwindigkeiten deuten auf einen Verlauf der Solvolyse über Vinylkationen.
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  • 50
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1264-1274 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Bicyclofulvenes, IV: Syntheses of Methylenetricyclo[4.2.1.02,5]nonane- and -tricyclo[3.2.1.02,4]octane DerivativesThe synthesis of 9-methylenetricyclo[4.2.1.02,5]nonane (3), 8-methylenetricyclo[3.2.1.02,4]octane (2) and their derivatives as well as that of methylenehomocubane (37) and 9-methylenepentacyclo-[4.3.0.02,4.03,8.05,7]nonane (38) is described.
    Notes: Die Darstellung von 9-Methylentricyclo[4.2.1.02,5]nonan (3), 8-Methylentricyclo[3.2.1.02,4]octan (2) und ihrer Derivate, sowie von Methylenhomocuban (37) und 9-Methylenpentacyclo-[4.3.0.02,4.03,8.05,7]nonan (38) wird beschrieben.
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  • 51
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1284-1293 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of 6-Deoxycryptosporin and Related CompoundsThe cis-hydroxylation of naphthopyran 5 yields the ketol 9 as the main product. Furthermore the epimeric ketol 11 and the hydroxylated quinones 2 and 13 can be isolated. Product 2 is the 6-deoxy compound of naturally occuring cryptosporin (1). The stereochemistry of the hydrogenation of the ketol 9 and of the reduction with sodium boron hydride and diisobutylaluminium hydride is reported.
    Notes: Die cis-Hydroxylierung des Naphthopyrans 5 liefert als Hauptprodukt das Ketol 9. Daneben können das epimere Ketol 11 und die hydroxylierten Chinone 2 und 13 isoliert werden. Das Syntheseprodukt 2 ist die 6-Desoxy-Verbindung des Naturstoffs Cryptosporin (1). Über die Stereochemie der katalytischen Hydrierung des Ketols 9 und die Reduktion mit Natriumborhydrid und Diisobutylaluminiumhydrid wird berichtet.
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  • 52
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1315-1322 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Influence of Various Anions on the Kinetics of the Acid Hydrolysis of the Cation Tetraaquamono(salicylaldehydato)chromium(III)The kinetics of the acid hydrolysis of the cation tetraaquamono(salicylaldehydato)chromium(III) in perchloric acid were studied at 70°C at constant ionic strength as a function of various anions added to the system. The hydrolysis is strongly accelerated by oxyanions like sulfate and nitrate, while halide anions like chloride and bromide affect the rate only slightly. The findings are explained on the basis of the „cis-effect“ of the oxyanions. The reaction is interpreted by an associative interchange mechanism (Ia).
    Notes: Die Kinetik der Säurehydrolyse des Tetraaquamono(salicylaldehydato)chrom(III)-Kations in perchlorsaurer Lösung wurde in Abhängigkeit vom Zusatz verschiedener Anionen bei 70°C und konstanter Ionenstärke untersucht. Die Hydrolyse wird durch die Oxyanionen Sulfat und Nitrat stark beschleunigt, während die Halogenid-Ionen Chlorid und Bromid die Reaktionsgeschwindigkeit nur geringfügig erhöhen. Dieses Ergebnis wird mit dem „cis-Effekt“ der Oxyanionen erklärt. Der Reaktionsablauf wird mit einem assoziativen Interchange-Mechanismus (Ia) interpretiert.
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1330-1336 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Heterocyclopolyaromatics, VI: Heterocyclotetraaromatics Containing Similar Kinds of NucleiHeterocyclotraaromatics have been unknown hitherto. Now were prepared 4 representatives (6a, 7, 9, 11) with nucleophilic and 1 representative (13b) with electrophilic aromatic ring members. With one exception the cyclisation of the precursors occurred by oxidative coupling.
    Notes: Heterocyclotetraaromaten waren bisher unbekannt. Es wurden 4 Vertreter (6a, 7, 9, 11) mit nucleophilen aromatischen Ringgliedern und 1 Vertreter (13b) mit elektrophilen aromatischen Ringgliedern dargestellt. Mit einer Ausnahme erfolgte die Cyclisierung der Vorstufen durch oxidative Kupplung.
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  • 54
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1337-1361 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Generation and Synthetic Use of Metallated Dimethylhydrazones Regio and Stereoselective Alkylation of Carbonyl CompoundsDimethylhydrazones (DMH's) 6-10 of enolizable aldehydes and ketones can be metallated quantitatively in α-position by n-butyllithium and/or lithium diisopropylamide in tetrahydrofuran. The lithio derivatives thus obtained (11-14) are highly reactive carbon nucleophiles. Their application as enolate equivalents is demonstrated via the sequence carbonyl compound, DMH-derivative, metallation, reaction with alkyl halides (→ 16, 18, 19), and cleavage to the α-substituted carbonyl compound (17) in a number of examples. Apart from some special cases, the alkylations occur regiospecificly at the less substituted carbon atom. Cyclohexanone derivatives are selectively axially alkylated, allowing for example the preparation of trans-disubstituted cyclohexanones. An efficient new conversion of dimethylhydrazones to carbonyl compounds under mild conditions (pH 7, room temperature) by oxidative hydrolysis has been developed. Advantages of the procedure are discussed briefly.
    Notes: Dimethylhydrazone (DMH's) 6-10 von enolisierbaren Aldehyden und Ketonen können mit n-Butyllithium und/oder Lithium-diisopropylamid in Tetrahydrofuran quantitativ in α-Stellung metalliert werden. Die so erhaltenen Lithiumderivate 11-14 sind hochreaktive Kohlenstoffnucleophile. Ihre Verwendung als Enolatäquivalente wird über die Sequenz Carbonylverbindung, DMH-Derivat. Metallierung, Reaktion mit Alkylhalogeniden (→ 16, 18, 19) und Spaltung zur α-substituierten Carbonylverbindung (17) an einer Anzahl von Beispielen demonstriert. Die Alkylierungen erfolgen, von Spezialfällen abgesehen, regiospezifisch am weniger substituierten Kohlenstoffatom. Cyclohexanonderivate werden stereoselektiv axial alkyliert, was zur Darstellung von trans-disubstituierten Cyclohexanonen ausgenutzt wird. Zur quantitativen Spaltung der Dimethylhydrazone zurück zu den Carbonylverbindungen unter milden Bedingungen (pH 7, Raumtemperatur) wurde eine neue oxidative Hydrolyse entwickelt. Die Vorteile der Methode werden kurz diskutiert.
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1384-1394 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Reactivity-Selectivity Principle, 2: Application of the Reactivity-Selectivity Principle to the Formation of SulfonamidesWhen sulfonyl chlorides 1 and anilines 2 react to sulfonamides 3 at a relatively low rate of formation, variation of the solvent has a greater effect than on reactions of more reactive starting compounds (table 1 and 2). On the other hand, selectivity increases with increasing reactivity when substituents X and Y are varied, and only one solvent is used5. This contradictory behaviour of the reactivity-selectivity principle (RSP)(1) for changing solvents and changing substituents can be explained by the opposing influence of substituents X and Y over bond formation and bond cleavage (transition states 4 and 5 in scheme 1). It is concluded that the failure of the RSP does not mean that the Hammond-Postulate does not hold.Selectivity measurements at various temperatures show that the isoselective temperatures (Tis) of these reaction series are in the range of 190°C (table 3 and 5, figure 2).
    Notes: Die Lösungsmittelvariation übt auf kleine Bildungsgeschwindigkeiten der Sulfonsäureamide 3 aus Sulfonsäurechloriden 1 und Anilinen 2 einen größeren Einfluß aus als auf die rascheren Umsetzungen reaktiverer Ausgangssubstanzen (s. Tab. 1 und 2). Im Gegensatz dazu steht der Anstieg der Selektivität mit zunehmender Reaktivität, wenn in einem Solvens die Substituenten X und Y der Sulfonsäurechloride 1 und Aniline 2 variiert werden(5). Dieser Widerspruch zwischen Gültigkeit des Reaktivitäts-Selektivitätsprinzips (RSP)(1) bei Lösungsmittelwechsel und seiner Ungültigkeit bei Substituentenvariation läßt sich mit dem gegenläufigen Einfluß der Substituenten X und Y auf die Bindungsbildung und den Bindungsbruch deuten (s. Übergangszustände 4 und 5 im Reaktionsschema 1). Es wird geschlossen, daß das Versagen des RSP nicht mit einem Versagen des Hammond-Postulats einhergeht.Selektivitätsmessungen bei unterschiedlichen Temperaturen zeigen, daß die isoselektiven Temperaturen (Tis) dieser Reaktionsserien bei ca. 190°C liegen (s. Tab. 3 und 5. Abb. 2).
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1404-1412 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Selective Double Bond Isomerizations with C-17 Inversion in 20-Methyl-A-nor-pregnadienesThe A-nor-steroid-diene 3a was prepared from the cyclosteroid 1 as well as from the A-nor-steroid-dienes 2 and 4 by HBr-induced regioselective double bond isomerization. Configurational inversion of the 17β-isopropyl group during isomerization (Δ8(9) or Δ8(14) → Δ14) of 1, 2, and 4, presumably via a spirocyclic intermediate, only occurs under special reaction conditions. 3a was converted into 20-methyl-14β,17α-pregn-4-en-3-one (9a).
    Notes: Aus dem Cyclosteroid 1 wie den A-Nor-Steroid-dienen 2 und 4 wurde durch HBr-induzierte, regioselektive Doppelbindungsisomerisierungen das 17α-konfigurierte A-Nor-Steroid-dien 3a dargestellt. Die Isomerisierungen (Δ8(9) bzw (Δ8(14) → Δ14) verlaufen bei 1, 2 und 4 bei Einhaltung spezieller Reaktionsbedingungen unter Konfigurationsinversion der 17β-Isopropylgruppe, vermutlich über ein spirocyclisches Zwischenprodukt. Aus 3a wurde 20-Methyl-14β,17α-pregn-4-en-3-on (9a) erhalten.
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    Keywords: Chemistry ; Inorganic Chemistry
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    Topics: Chemistry and Pharmacology
    Description / Table of Contents: High-energetic Molecules, VI: MINDO/3 Calculations on the Thermolysis of 1,2-Dioxetanes. Evidence for a CC Biradical as Transition State of the Fragmentation to Products in the Electronic Ground StateMINDO/3 calculations of the conformation and bond strengths of substituted 1,2-dioxetanes (3-7) show that the O—O bond is strengthened by increasing alkyl substitution. This stabilizes the molecule and increases the concerted nature of the fragmentation. Substituents with lone pairs (OR, F) tend to weaken the C—C bond to the extent that cleavage to ground state products starts with C—C bond breaking.
    Notes: MINDO/3-Berechnungen der Konformation und der Bindungsstärken bei substituierten 1,2-Dioxetanen (3-7) zeigen, daß die O—O-Bindung durch zunehmende Alkylsubstitution gestärkt wird. Damit sollte die Stabilität des Moleküls und der Synchroncharakter des Zerfallsmechanismus zunehmen. Substituenten mit freie Elektronenpaaren (OR, F) hingegen schwächen die C—C-Bindung soweit, daß der Zerfall zu Produkten im elektronischen Grundzustand unter bevorzugtem Öffnen der C—C-Bindung möglich erscheint.
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1446-1452 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of Long Chain Terminally Bifunctionalised Alkane and Alkyne DerivativesBy reaction of the Grignard derivative of compound 1 with α,ω-disubstituted alkanes 2-4, 7 and catalysis with Li2CuCl4 compounds 6a, b, 8, 9 are synthesized. The reaction of the lithium salt of alkyne 12 with the dihalogenalkanes 10a, 11b in THF/HMPT followed by hydrolysis gives compounds 14a, b with chains of 38 and 46 carbon atoms. By repetition of this reaction sequence the alkyne derivatives 18a, b with chains of 64 and 72 carbon atoms are obtained.
    Notes: Durch Umsetzung der Grignard-Verbindung von 1 mit den α,ω-disubstituierten Alkanen 2-4, 7 unter Katalyse mit Li2CuCl4 werden die Verbindungen 6a, b, 8, 9 synthetisiert. Die Reaktion des Lithiumsalzes von 12 mit den Dihalogenalkanen 10a, 11b in THF/HMPT und nachfolgende Hydrolyse ergibt die Verbindungen 14a, b mit Ketten von 38 und 46 Kohlenstoffatomen. Durch Wiederholung dieser Reaktionsfolge werden die Alkin-Derivate 18a, b mit Ketten von 64 und 72 Kohlenstoffatomen erhalten.
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1471-1474 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Light-induced [2 + 2] Cycloaddition Reactions of Thiones with Cyclic AlkenesUnder n→π* excitation using sodium light, xanthione (1) combines with acenaphthylene, indene or N-phenyl maleoylimide in good yields with formation of the spirothietane drivatives 3, 7, or 8, respectively. The analogous photoreactions (λ ≍ 400 nm) of the 2-thioparabanate 4 in the presence of indene, benzo[b]furan or N-phenyl maleoylimide proceed with formation of the spirothietanes 6a, b, or 9, respectively. The thietane structures are consistent with spectroscopic data.
    Notes: Bei n→π*-Anregung mit Natrium-Licht vereinigt sich Xanthion (1) mit Acenaphthylen, Inden bzw. N-Phenylmaleinimid in guten Ausbeuten zu den Spirothietan-Derivaten 3, 7 bzw. 8. Die analogen Photoreaktionen (λ ≍ 400 nm) der 2-Thioparabansäure 4 in Gegenwart von Inden, Benzo[b]furan bzw. N-Phenylmaleinimid verlaufen unter Bildung der Spirothietane 6a, b bzw. 9. Spektroskopische Daten sichern die Konstitutionen.
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1475-1485 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cycloaddition Reactions of Heterocumulenes, XII: Reaction of Persubstituted Isothioureas with IsocyanatesThe isothiourea 1a reacts with the sulfonyl isocyanates 2a-c to give the stable 1,4-dipoles 3a-c, which can be characterized spectroscopically as well as by protonation to yield the ureas 7. For one example (3b) the molecular structure is elucidated by an X-ray structural analysis. The isothioureas 1b-g with bulkier substituents react with 2a, b in a [2 + 2]-cycloreversion to give the isocyanates 5 and the N-sulfonylisothioureas 6. Using (thio)benzoyl isocyanates (2d, e) the same type of reaction leads to the N-(thio)benzoylisothioureas 8.
    Notes: Der Isothioharnstoff 1a reagiert mit den Sulfonylisocyanaten 2a-c zu den stabilen 1,4-Dipolen 3a-c, die sich spektroskopisch sowie durch Protonierung zu den Harnstoffen 7 charakterisieren lassen. An einem Beispiel (3b) wurde die Molekülstruktur durch eine Röntgenstrukturanalyse aufgeklärt. Die höher substituierten Isothioharnstoffe 1b-g setzen sich mit 2a, b in einer [2 + 2]-Cycloreversion zu den Isocyanaten 5 und den N-Sulfonylisothioharnstoffen 6 um. Mit (Thio)-Benzoylisocyanat (2d, e) entstehen nach dem gleichen Reaktionsprinzip N-(Thio)Benzoylisothioharnstoffe 8.
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1527-1532 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stereoselective Formation of 2r-Halogeno-3c-dimethylamino-4t-phenylthietane 1,1-Dioxides and 2-Halogeno-4-phenyl-2H-thiete 1,1-DioxidesN,N-Dimethyl-(E)-styrylamine (1) reacts with halogen-substituted methanesulfonyl chlorides (2a-e) to give acyclic substituted products (4a-e) and stereoselectively 2r-halogeno-3c-dimethylamino-4t-phenylthietane 1,1-dioxides (3a-c). Cope-elimination from 3a-c produced only the 2-halogeno-4-phenyl-2H-thiete 1,1-dioxides (5a-c). The additional halogenation of 4-phenyl-2H-thiete 1,1-dioxide in the 2-position and the oxidation to the 2-oxo derivative did not succeed.
    Notes: Aus N,N-Dimethyl-(E)-styrylamin (1) und halogensubstituierten Methansulfonylchloriden (2a-e) entstehen neben acyclischen Substitutionsprodukten (4a-e) mit hoher Selektivität die 2r-Halogen-3c-dimethylamino-4t-phenylthietan-1,1-dioxide (3a-c). Durch Cope-Eliminierung aus 3a-c erhält man ausschließlich die 2-Halogen-4-pheny-2H-thiet-1,1-dioxide (5a-c). Die nachträgliche Einführung von Halogen in die 2-Position von 4-Phenyl-2H-thiet 1,1-dioxid gelingt ebensowenig wie dessen Oxidation zum 2-Oxoderivat.
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1521-1526 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: New Hetero Anellated Benzo[b]thiophene 1,1-Dioxides2-Benzoyl-3-chlorobenzo[b]thiophene 1,1-dioxide reacts with semicarbazide. 4-methylbenzamidrazone, 1,8-diaminonaphthaline to give 1c-e, with KSCN to give the isothiocyanate 1g. The hydrolysis of 1g and also the reaction of ammonia with 1a leads to 1h. 1a reacts with sodium-azide to form 2b, and with hydrazine to form 2a. The hydrolysis of 1d results in 3. Ethyl β-amino-crotonate condenses with 1a to the pyridine derivative 4. The pyrimidine compounds 6a-c can be prepared by the reaction of 1a with guanidine, benzamidine and acetamidine respectively. 1g reacts with aniline to give 5, o-phenylenediamine, ethylenediamine and N-methylethylenediamine on reaction with 1a give the diazepine derivatives 8a-c. The reaction of 1a with o-aminothiophenol gives the benzothiazole derivative 9.
    Notes: 2-Benzoyl-3-chlorbenzo[b]thiophen-1,1-dioxid (1a) reagiert mit Semicarbazid, 4-Methylbenz-amidrazon, 1,8-Diaminonaphthalin zu 1c-e, mit KSCN zu dem Senföl 1g: durch Hydrolyse von 1g erhält man 1h, zu dem man auch durch Umsetzung von 1a mit Ammoniak gelangt. 1a reagiert mit Natriumazid zu 2b, mit Hydrazin zu 2a. Saure Hydrolyse von 1d führt zur Verbindung 3. 3-Aminocrotonsäure-ethylester kondensiert mit 1a zum Pyridinderivat 4: mit Guanidin, Benzamidin und Acetamidin erhält man die Pyrimidinabkömmlinge 6a-c. 1g reagiert mit Anilin zu 5, 1a mit o-Phenylendiamin, Ethylendiamin und N-Methylethylendiamin zu Diazepinverbindungen 8a-c, mit o-Aminothiophenol zum Benzothiazol 9.
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1549-1557 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Formation of Oxirenes from Cyclic α-DiazoketonesThe reactions following the nitrogen elimination from 2-diazo-12-methyl-1-cyclododecanone (15) are studied. In the intermediate 12-membered α-oxocarbene 17 the first example of a photochemically and thermally induced 1,2-shift of oxygen in a cyclic α-oxocarbene is described. The rearrangement involves the condensed oxirene system 18. The occurrence of the two isomeric α-oxocarbenes 17 and 17′ is demonstrated by the subsequent 1,2-hydrogen rearrangement to isomeric α,β-unsaturated ketones (19, 20 and 19′, 20′). In contrast no oxirene participation is found in the silver oxide-catalysed reaction.
    Notes: Die Folgereaktionen nach der Stickstoff-Abspaltung aus 2-Diazo-12-methyl-1-cyclododecanon (15) werden untersucht. Am intermediären 12-Ring-α-oxocarben 17 wird das erste Beispiel einer photochemisch und thermisch ausgelösten 1,2-Sauerstoffverschiebung in cyclischen α-Oxocarbenen beschrieben. Die Umlagerung verläuft über das kondensierte Oxiren-System 18. Das Auftreten der beiden isomeren α-Oxocarbene 17 und 17′ wird durch die nachfolgende 1,2-Wasserstoff-verschiebung zu isomeren α,β-ungesättigten Ketonen (19, 20 und 19′, 20′) belegt. Im Gegensatz dazu wird bei der silberoxid-katalysierten Reaktion keine Oxiren-Beteiligung gefunden.
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1578-1590 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Über die konformative Präferenz in substituierten Cyclopentadienyl- und Heterocyclopentadienyl-KomplexenMO-Berechnungen ergeben erhebliche Barrieren für die internen Rotationen in Thiadiborolen-Fe(CO)3- und Diazaborolen-Cr(CO)3-Komplexen. Die Gleichgewichtsgeometrien der zwei Moleküle sollten verschieden sein. Eine MO-Fragmentanalyse erklärt diese Ergebnisse und führt darüberhinaus zu einer ganz allgemeinen Analyse der Rotationsbarrieren in Heterocyclopentadienyl- und substituierten Cyclopentadienyl-ML3- und -ML2-Komplexen. Für letztere wird ein gleitender Übergang von η5- nach η2-Koordination vorhergesagt.
    Notes: Molecular orbital calculations indicate substantial barriers to internal rotation in thiadiborolene-Fe(CO)3 and diazaborolene-Cr(CO)3 complexes. The equilibrium geometry of the two molecules should also differ. A fragment analysis explains these results and leads to a general analysis of rotational barriers in heterocyclopentadienyl and substituted cyclopentadienyl-ML3 and -ML2 complexes. In the latter an interesting “slipping” from η5 toward η2 coordination is predicted.
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1591-1602 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cycloheptatrien- und Fulven-Cr(CO)3-KomplexeIm Tricarbonylchrom(0)-Komplex von 1,6-Methano[10]annulen und in einigen verwandten Komplexen nimmt die Cr(CO)3-Einheit verglichen mit allen anderen Hexatrien-Cr(CO)3-Systemen eine anomale Orientierung relativ zum Polyen ein. Eine theoretische Analyse dieses Problems zeigt, daß diese Vorzugskonformation eng mit der Cycloheptatrien-Norcaradien-Valenztautomerie zusammenhängt. Mögliche Wege, die Rotationsbarriere in derartigen Komplexen zu beeinflussen, werden aufgezeigt. Vorzugskonformation, Rotationsbarriere und Abknicken der exocyclischen Methylengruppe in Tricarbonyl(η6-fulven)chrom(0) werden diskutiert und die Analyse wird auf die analogen Benzyl-Cr(CO)3- und Cyclobutadiencarbinyl-Fe(CO)3-Kationen ausgedehnt. Die Konformation dieser Komplexe wird solchen gegenübergestellt, die zwei Elektronen mehr enthalten.
    Notes: 1,6-Methano[10]annulene-Cr(CO)3 and several related complexes adopt an anomalous orientation of the Cr(CO)3 unit with respect to the polyene, compared to all other hexatriene-Cr(CO)3 complexes. A theoretical analysis of this problem shows that these conformational preferences are closely related to the cycloheptatriene-norcaradiene valence tautomerism. Several strategies for influencing the barrier to internal rotation in these complexes are presented. An analysis of the conformational preference, rotational barrier, and bending of the exocyclic methylene group in fulvene-Cr(CO)3 is also discussed. This is extended to the analogous benzyl-Cr(CO)3 and cyclobutadiene-carbinyl-Fe(CO)3 cations. Finally, the orientations of these complexes are contrasted to those containing two more electrons.
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1619-1626 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Chlorination of N-Substituted CarboxamidesN,N′-Dimethyl- (1a-c). N,N,N′,N′-tetramethyl- (9a-c), and N,N′-dimethyl-N,N′-diphenyl-diamides are transformed into the corresponding bis(chloromethyl)- (2a-c, 13, 14) or tetrakis-(chloromethyl)diamides (10a-c) by chlorination with simultaneous UV-irradiation. Chlorination of N,N′-dimethyldichloromalonamide (1c) with excess chlorine leads to N,N′-bis(dichloro-methylene)dichloromalonamide (5) in good yield. The compounds are characterized by NMR spectra and by substitution reactions. N-(Dichloromethylene)benzamide (15) reacts with dimethyl sulfoxide to give N-benzoyl-S,S-dimethylsulfimide (17), which decomposes thermally in part into N,N-methylenedibenzamide (19).
    Notes: N,N′-Dimethyl- (1a-c), N,N,N,N′-Tetramethyl- (9a-c) und N,N′-Dimethyl-N,N′-diphenyl-diamide werden durch Chlorierung unter UV-Bestrahlung in die entsprechenden Bis(chlormethyl)- (2a-c, 13, 14) bzw. Tetrakis(chlormethyl)diamide (10a-c) übergeführt. Chlorierung von N,N′-Dimethyldichlormalonamid (1c) mit überschüssigem Chlor führt in guter Ausbeute zum N,N′-Bis(dichlormethylen)dichlormalonamid (5). Die Verbindungen werden NMR-spektroskopisch und durch Substitutionsreaktionen charakterisiert. N-(Dichlormethylen)benzamid (15) reagiert mit Dimethylsulfoxid zum N-Benzoyl-S,S-dimethylsulfimid (17), das thermisch teilweise zu N,N′-Methylendibenzamid (19) abgebaut wird.
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1627-1631 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Alkynyl Compounds of Transition Metals, XXXV: Complexes of Palladium(II) Acetylides with 1,2-Bis(diphenylphosphino)ethaneThe complexes cis-[Pd(C ≡ CR)2(dpe)] and cis-[Pd(C ≡ CC6H4C ≡ CH-o)(Cl)(dpe)] have been prepared according to the equations (1) and (2) (dpe = (C6H5)2PCH2CH2P(C6H5)2; R = H, C6H5, CH3). The cis-structure of these complexes is confirmed by their IR spectra and by 31P NMR data.  -  The complexes cis-[Pd(C2R)2(dpe)] react with excess KC ≡ CR to give the not quite pure tetrakis(alkynyl)palladates(II), K2[Pd(C2R)4], according to the equation (4). Both types of complexes can be reduced according to (5) or (6) to the palladium(0) complexes K2[Pd(C2R)2] known long ago.
    Notes: Nach den Gleichungen (1) und (2) wurden Komplexe des Typs cis-[Pd(C ≡ CR)2(dpe)] sowie cis-[Pd(C ≡ CC6H4C ≡ CH-o)(Cl)(dpe)] dargestellt (dpe = (C6H5)2PCH2CH2P(C6H5)2; R = H, C6H5, CH3). Die cis-Struktur dieser Verbindungen wird durch ihre IR-Spektren bzw. 31P-NMR-Daten belegt.  -  Die Komplexe cis-[Pd(C2R)2(dpe)] reagieren mit überschüssigem KC ≡ CR gemäß Gleichung (4) zu den nicht ganz reinen Tetrakis(alkinyl)palladaten(II). K2[Pd(C2R)4]. Beide Komplextypen lassen sich gemäß Gleichung (5) oder (6) zu den schon lange bekannten Palladium(0)-Verbindungen K2[Pd(C2R)2] reduzieren.
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1632-1645 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: [3.3]-Sigmatropic Rearrangements at Glycals and Pseudoglycals3,4,6-Tri-O-acetyl-1,2-dideoxy-D-arabino-hex-1-enopyranose (1a) reacts in acetonitrile with sodium azide, potassium thiocyanate and potassium O-ethyl-dithiocarbonate in the presence of boron trifluoride-diethylether to afford the corresponding C-1-substituted 2,3-dideoxy-2-enopyranosyl compounds 2a, 3a, 11a and 11b. They easily rearrange at room temperature to the C-3-substituted glycals 4a, 5a, 12a, and 12b. In case of the azido compounds the rearrangement is reversible and equilibria are established between glycals and pseudoglycals. Similar results are found with other glycals. Allylic rearrangement of glycals can be used to prepare branched chain sugars as is shown by conversion of 14 to 15 and the formation of 18 from 17.
    Notes: 3,4,6-Tri-O-acetyl-1,2-didesoxy-D-arabino-hex-1-enopyranose (1a) reagiert in Acetonitril mit Natriumazid, Kaliumthiocyanat und Kalium-O-ethyl-dithiocarbonat unter Bortrifluorid-Etherat-Katalyse zu den entsprechend in 1-Stellung substituierten 2,3-Didesoxy-2-enopyranosyl-Verbindungen 2a, 3a, 11a und 11b. Sie unterliegen bereits bei Raumtemperatur einer allylischen Umlagerung unter Bildung der 3-substituierten Glycale 4a, 5a, 12a und 12b. Im Falle der Azidoverbindungen sind die Umlagerungen reversibel und führen zu Gleichgewichten zwischen Glycalen und Pseudoglycalen. Ähnliche Ergebnisse werden mit anderen Glycalen erhalten. Durch Allylumlagerung an Glycalen sind auch C-verzweigte Zucker zugänglich, wie durch die Umlagerung von 14 nach 15 und die Bildung von 18 aus 17 gezeigt werden konnte.
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1650-1652 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Functional Derivatives of Trimethylphosphine. VII: Ambivalent Behaviour of Tetrakis(trimethylphosphine) iron: Reaction with CH3ITreatment of the title complex 1a ⇌ 1b with CH3I in pentane at ambient temperature yields L4(CH3)Fel(L = P(CH3)3). The reaction is shown to proceed via oxidative addition to the iron(0) isomer 1a. In ether at lower temperature, a reaction with the iron(II) isomer 1b predominates, which leaves its hydridoiron function unchanged. So, a hydridoiron iodide complex is formed, probably by attack on the Fe—C bond.
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 314-319 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Fused 2H-1,3-Oxazin-2-ones and -thionesCyclisation of 2-hydroxybenzimidic acid derivatives 1 and 2 by carbonyl reagents yields 2H-1,3-benzoxazin-2-ones 3 and 4. Multinucleous compounds 6 resp. 8 are formed starting with heterocyclic o-hydroxycarboximidic acid derivatives 5 resp. N,N′-bridged amidines 7.
    Notes: Durch Ringschluß von 2-Hydroxybenzimidsäure-Derivaten 1 und 2 mit Carbonyl-Reagenzien werden 2H-1,3-Benzoxazin-2-one 3 und 4 erhalten. Heterocyclische o-Hydroxycarboximidsäure-Derivate 5 bzw. N,N′-überbrückte Amidine 7 liefern die mehrkernigen Analoga 6 bzw. 8.
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 309-313 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Heterocyclic Seven-membered Ring Compounds, XX: Crystal Structure of a 1-Benzothiepin 1- Oxide3,5-Dimethoxy-4-phenyl-1-benzothiepin 1-oxide crystallizes in the rhombic space group P212121. The structure has been determined by X-ray diffraction using direct methods. The seven-membered ring exists in a big vaulted boat conformation with the oxygen of the sulfoxide function in exo-position.
    Notes: 3,5-Dimethoxy-4-phenyl-1-benzothiepin-1-oxid kristallisiert in der rhombischen Raumgruppe P212121. Die Struktur der Verbindung wurde, röntgenographisch mittels direkter Methoden bestimmt. Der Siebenring besitzt eine stark aufgewölbte Bootform mit exo-ständigem Sauerstoff der Sulfoxid-Funktion.
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 282-298 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A Degenerate Rearrangement of cis-Bicyclo[6.1.0]nona-2,4,6-trieneThe synthesis and the thermal behaviour of the diastereomeric 9-methyl- and 4,9-dimethyl-cis-bicyclo[6.1.0]nonatriene-9-carbonitriles 1a,b and 10a,b are reported. The bicyclo[6.1.0]nonatriene ⇌ bicyclo[6.1.0]nonatriene rearrangement which is degenerate in the cases of 1a and 1b could be detected experimentally with the aid of the dimethyl derivatives 10a and 10b. At 102.5°C ([2H6]benzene) the mutual interconversion 10a ⇌ 11a ⇌ 12a ⇌ 13a and 10b ⇌ 11b ⇌ 12b ⇌ 13b, respectively, proceeds stereospecifically with inversion at the migrating carbon atom C-9 as postulated by Woodward and Hoffmann. Apart from the stereochemical result the concerted nature of this rearrangement is made plausible by the energetic parameter. The difference in the Gibbs energies of activation for the cleavage of the cyclopropane bond C-1 - C-9 in the bicyclo[6.1.0]-nonatriene → bicyclo[4.2.1]nonatriene isomerization 1a → 7a + 7b, 1b → 7a + 7b and in the rearrangement 10a → 11a, 10b → 11b amounts to ca. 7 kcal/mol in each case and suggests an aromatic transition state for the degenerate rearrangement.
    Notes: Synthese und thermisches Verhalten der diastereomeren 9-Methyl- und 4,9-Dimethyl-cis-bicyclo-[6.1.0]nona-2,4,6-trien-9-carbonitrile 1a,b und 10a,b werden beschrieben. Die in den Systemen 1a und 1b entartete Bicyclo[6.1.0]nonatrien ⇌ Bicyclo[6.1.0]nonatrien-Umlagerung konnte am Beispiel der Dimethylderivate 10a und 10b experimentell nachgewiesen werden. Die wechselseitige Umlagerung 10a ⇌ 11a ⇌ 12a ⇌ 13a bzw. 10b ⇌ 11b ⇌ 12b ⇌ 13b erfolgt bei 102.5°C ([D6]Benzol) stereospezifisch mit der von Woodward und Hoffmann postulierten Inversion am wandernden Kohlenstoff C-9. Außer durch das stereochemische Ergebnis wird der synchrone Charakter dieser Umlagerung durch den energetischen Parameter wahrscheinlich gemacht. Der Unterschied der Gibbs-Aktivierungsenergie für die Öffnung der Cyclopropanbindung C-1 - C-9 in der Bicyclo[6.1.0]nonatrien → Bicyclo[4.2.1]nonatrien-Isomerisierung 1a → 7a + 7b, 1b → 7a + 7b und in der Umlagerung 10a → 11a, 10b → 11b beträgt in jedem Fall ca. 7 kcal/mol und legt einen aromatischen Übergangszustand für die entartete Umlagerung nahe.
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 320-334 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Substituent Effect of the Guanidino and of the Guanidinium Group, Part I: The Effect on 19F NMR Spectra of Fluorobenzenes and on the Aromatic SubstitutionTaft's substituent parameters σ1, and σR are calculated from 19F NMR spectra of N-(fluorophenyl)-guanidines and their salts. The rearrangement of N-nitro-N′-phenylguanidine (1) in strong acid is shown to be an intermolecular nitration of the N-phenylguanidinium cation by NO2⊕. Both o-and p-nitro derivatives are formed at a rate which is but slightly retarded compared to that with benzene.  -  Together with results from 35Cl-NQR spectra(1) and redox potentials of guanidinoquinones(2) the above findings show that the guanidino group exerts only a + M-effect.  -  In addition to the expected  -  I-effect the guanidinium function shows a distinct + M-effect in spite of its positive charge and the reduced charge distribution in the guanidine system.
    Notes: Aus den 19F-NMR-Spektren von N-(Fluorphenyl)guanidinen und ihren Salzen werden die Taftschen σ1- und σR-Werte errechnet. Die Umlagerung des N-Nitro-N′-phenylguanidins (1) in starker Säure verläuft intermolekular als Nitrierung eines N-Phenylguanidinium-Ions durch NO2⊕. Es entstehen o- und p-Nitroderivate mit relativ zu Benzol nur geringfügig reduzierter Geschwindigkeit. -- Zusammen mit 35Cl-NQR-Messungen (1) und der Beeinflussung von Redoxpotentialen bei Guanidinochinonen(2) zeigen diese Befunde, daß die Guanidinogruppe als mesomerer Elektronendonator wirkt.  -  Neben dem erwarteten  -  I-Effekt zeigt die Guanidiniumgruppe trotz ihrer positiven Ladung und der Einschränkung der Mesomerie im Guanidinsystem einen deutlichen + M-Effekt.
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 356-360 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thiadiborolene Complexes of Chromium and Molybdenum3,4-Diethyl-2,5-dimethyl-Δ3-1,2,5-thiadiborolene (1) reacts with the hexacarbonyls of chromium and molybdenum photochemically to yield the mono- and bis(thiadiborolene) complexes 2, 3 and 4, 5. The latter exhibit higher thermal and hydrolytical stability than the tetracarbonyl compounds. 4 is also obtained from 1 and (C6H6)Cr(CO)3. From spectroscopic data it is concluded that pentahapto-thiadiborolene complexes and cis arrangement of the CO groups in 4 and 5 are present.
    Notes: 3,4-Diethyl-2,5-dimethyl-Δ3-1,2,5-thiadiborolen (1) reagiert mit den Hexacarbonylen des Chroms und Molybdäns photochemisch zu den Mono- und Bis(thiadiborolen)-Komplexen 2, 3 und 4, 5. Letztere zeigen größere thermische und hydrolytische Stabilität als die Tetracarbonyl-Verbindungen. 4 entsteht auch aus 1 und (C6H6)Cr(CO)3. Aus den spektroskopischen Daten wird auf das Vorliegen von pentahapto-Thiadiborolen-Komplexen und cis-Anordnung der CO-Gruppen in 4 und 5 geschlossen.
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 361-366 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On Amino Acids and Peptides, XXIV: Radically and Photochemically Initiated Oxidation of Amino Acid DerivativesIn an atmosphere of oxygen cyclic peptides are photochemically oxidized to mono- and bishydroperoxides (1, 2, 4, 6, 8, 10, 11) in the presence of benzophenone as catalyst. The same products are also formed using radical initiators.
    Notes: Cyclopeptide werden in einer Sauerstoffatmosphäre photochemisch-radikalisch unter Benzophenon-Katalyse zu Mono- und Bishydroperoxiden (1, 2, 4, 6, 8, 10, 11) oxidiert. Die gleichen Produkte entstehen auch bei der Oxidation mit Hilfe von Radikalstartern.
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1753-1762 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Organic Electrochemistry, I: Electrochemical Reduction of 2,3-Dioxo-1,2,3,4-tetrahydroquinoxalines and Autoxidation of the Reduction ProductsThe electrochemical reduction of 1-methyl- (2) and 1,4-dimethyl-2,3-dioxo-1,2,3,4-tetrahydro-quinoxaline (3) leads in acidic media in an unusual 4 electron reduction step to 1-methyl- (4) and 1,4-dimethyl-3-oxo-1,2,3,4-tetrahydroquinoxaline (5), respectively. These compounds are converted to the starting material by autoxidation. The mechanisms of these reduction and reoxidation processes are discussed and proven experimentally. It is shown that 1-methyl-3-oxo-3.4-dihydroquinoxalinium cations (15, 16) are intermediates in the autoxidation process and that the carbonyl oxygen introduced in 2-position is derived from water.
    Notes: Die elektrochemische Reduktion des 1-Methyl- (2) und 1,4-Dimethyl-2,3-dioxo-1,2,3,4-tetra-hydrochinoxalins (3) führt im sauren Medium in einer ungewöhnlichen vierelektronigen Reduktionsstufe zu 1-Methyl- (4) bzw. 1,4-Dimethyl-3-oxo-1,2,3,4-tetrahydrochinoxalin (5), die unter Autoxidation jeweils die Ausgangsverbindungen zurückbilden. Die Mechanismen der Reduktions-und Reoxidationsprozesse werden diskutiert und experimentell belegt. Es wird gezeigt, daß bei der Autoxidation die Stufe eines 1-Methyl-3-oxo-3,4-dihydrochinoxalinium-Kations (15, 16) durchlaufen wird und der eingeführte 2-Carbonylsauerstoff aus dem Wasser stammt.
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1763-1779 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Organic Electrochemistry, II: Synthesis and Electrochemical Behaviour of 6,7-Dioxotetrahydropteridines and 2,3-Dioxotetrahydropyrido-pyrazinesThe 6,7-dioxotetrahydropteridines 1-9 have been synthesized and studied with respect to cathodic electroreduction. The 8-unsubstituted derivatives 1-5 are reduced in acidic as well as basic media in a four electron process to the corresponding 6-oxo-5,6,7,8-tetrahydropteridines (13-17), whereas the reduction of the 8-alkyl derivatives 6-9 stops after a two electron uptake at the 8-alkyl-7-hydroxy-6-oxo-5,6,7,8-tetrahydro level (19-22). The 2,3-dioxotetrahydropyrido-pyrazines 10-12 showed an analogous behaviour with formal reduction of one oxo function to give 23-26 and small amounts of dimeric products (27, 28). The structures of the newly synthesized compounds have been proven by spectroscopic investigations.
    Notes: Die 6,7-Dioxotetrahydropteridine 1-9 warden synthetisiert und der kathodischen Elektro-reduktion unterworfen. Die 8-unsubstituierten Derivate 1-5 werden im allgemeinen sowohl im sauren als auch alkalischen Medium in einem vierelektronigen Prozeß zu den entsprechenden 6-Oxo-5,6,7,8-tetrahydropteridinen (13-17) reduziert, wogegen bei den 8-Alkyl-Derivaten 6-9 die Reduktion nach Aufnahme von 2 Elektronen auf der 8-Alkyl-7-hydroxy-6-oxo-5,6,7,8-tetrahydro-Stufe (19-22) zum Stillstand kommt. Die 2,3-Dioxotetrahydropyrido-pyrazine 10-12 zeigen analoges Reaktionsverhalten unter formaler Reduktion einer Oxo-Funktion zu 23-26 neben der Bildung kleiner Mengen an Dimeren (27, 28). Die Konstitutionen der neu synthetisierten Verbindungen werden durch spektroskopische Untersuchungen gesichert.
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  • 78
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1815-1823 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Diazadiphosphetidines by Cycloaddition of PhosphazenesThe iminophosphoranes 2a-i and 6a-c react with aminodiiminophosphorane 1 to give stable adducts to which we ascribe the cyclic structures 3a-i or 7a,b and 8b,c, resp., on the basis of spectroscopic data and thermal cleavage.
    Notes: Die Iminophosphorane 2a-i und 6a-c bilden mit Aminodiiminophosphoran 1 stabile Addukte, für die aufgrund der spektroskopischen Befunde und der thermolytischen Spaltung die cyclischen Strukturen 3a-i bzw. 7a,b und 8b,c vorgeschlagen werden.
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  • 79
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1833-1838 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 35Cl NMR Studies on Alkyl and Alkenyl Chlorides35Cl chemical shifts (δ35Cl) are reported for 17 alkyl chlorides and 4 alkenyl chlorides. A linear correlation results between δ35Cl and δ19F of analogous compounds of the type CnH2n+1 X and CnH2nX2. This relationship is not valid if there are more than two halogen atoms bonded to one carbon atom and also in the case of alkenyl halides. The reasons for this are discussed. There is no linear correlation between the calculated charge density on chlorine and δ35Cl.
    Notes: 35)Cl-chemische Verschiebungen (δ35Cl) von 17 Alkylchloriden und 4 Alkenylchloriden werden mitgeteilt. Eine lineare Korrelation zwischen δ35Cl und δ19F analoger Fluoride für Alkylhalogenide des Typs CnH2n+1 X und CnH2nX2 zeigt den gleichsinnigen Einfluß des Alkylrestes auf die chemischen Verschiebungen δ35Cl und δ19 F. Bei mehr als zwei Halogenatomen pro Kohlenstoff versagt diese Beziehung, ebenso bei Alkenylhalogeniden; Gründe hierfür werden diskutiert. Zwischen der berechneten Ladungsdichte am Chlor und δ35Cl läßt sich keine lineare Korrelation herstellen.
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  • 80
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 388-399 
    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, 6: Radicals with Bicyclooctane, Tricyclooctane, and Tetracyclooctane SkeletonRadicals with bicyclo[3.2.1]octane skeleton are generated (2, 11-13) in order to investigate rearrangements to tricyclic (3) and tetracyclic (4) radicals. It is shown by product analysis and by ESR spectroscopy that radicals with bicyclo[3.2.1]octa-2.6-dienyl structure are most stable. This maintains even if substituents which can stabilize structure 4 are introduced in 3-position of 2. Secondary radicals which derive from tricyclo[3.2.1.02,7]oct-3-ene (17), tetracyclo[3.2.1.02,7.04,6]-octane (18), bicyclo[2.2.2]octa-2,5-diene (25) and bicyclo[2.2.2]oct-2-ene (26) also rearrange to 2. Bicyclo[3.2.1]octa-2,6-dienyl radical constitutes the most stable member in this series of radicals.
    Notes: Radikale mit Bicyclo[3.2.1]octan-Gerüst (2, 11-13) werden auf eine Umlagerung in tricyclische (3) und tetracyclische Radikale (4) untersucht. Produktanalysen und ESR-spektroskopische Studien zeigen, daß die Radikale mit Bicyclo[3.2.1]octa-2,6-dienyl-Gerüst am stabilsten sind. Dies trifft auch zu, wenn in 3-Stellung (11-13) von 2 radikalstabilisierende Gruppen eingeführt werden, welche die Konstitution 4, nicht aber 2 stabilisieren können. Auf Grund dieser Ergebnisse ist es nicht überraschend, daß die von Tricyclo[3.2.1.02,7]oct-3-en (17) und Tetracyclo[3.2.1.02,7.04,6]-octan (18) abgeleiteten Radikale sich in das Bicyclo[3.2.1]octa-2,6-dienyl-Radikal 2 umlagern. Gleiches trifft für die aus Bicyclo[2.2.2]octa-2,5-dien (25) und Bicyclo[2.2.2]oct-2-en (26) erzeugten sekundären Radikale 21 und 22 zu.
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  • 81
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1873-1882 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Deamination Reactions, 30: Decomposition of Bicyclo[4.1.0]hept-2-ene-7-diazonium Ionsexo-Bicyclo[4.1.0]hept-2-ene-7-diazonium ions (16) have been generated from the corresponding nitrosourea 15 and base. In weakly alkaline methanol 7-anti-methoxybicyclo[2.2.1]hept-2-ene (17), 2-exo-methoxybicyclo[3.2.0]hept-6-ene (19), 7-exo-methoxybicyclo[4.1.0]hept-2-ene (20), 5-methoxy-1,3-cycloheptadiene (21), and 3-methoxy-1,4-cycloheptadiene (22) were obtained. 22 is formed by isomerization of 3-methoxy-1(Z),4(E)-cycloheptadiene (30) which was trapped in the presence of furan to give the adducts 25 and 26. 19 is thought to arise by intramolecular cyclization of 5-methoxy-1(Z),3(E)-cycloheptadiene (31). The configurations of 19, 20, 25. and 26 suggest attack of methanol on the partially opened cyclopropyl cation 29. - In CH3OD/HCO2Na all products incorporated approximately the same amount of deuterium. The location of D in 17 indicates that double bond participation in 16 leads immediately to the 7-norbornenyl cation 33, without intervention of the tricyclic cation 32. In the presence of lithium methoxide the products 17 and 18, derived from the 7-norbornenyl cation 33, predominated while 19-22 virtually disappeared. The variation in products is explained in terms of the carbene rearrangement 38 → 41, followed by protonation of 41 to give 33.
    Notes: exo-Bicyclo[4.1.0]hept-2-en-7-diazonium-Ionen (16) wurden durch alkalische Spaltung des entsprechenden Nitrosoharnstoffs 15 erzeugt. In schwach alkalischem Methanol erhielten wir 7-anti-Methoxybicyclo[2.2.1]hept-2-en (17), 2-exo-Methoxybicyclo[3.2.0]hept-6-en (19) 7-exo-Methoxybicyclo[4.1.0]hept-2-en (20), 5-Methoxy-1,3-cycloheptadien (21) und 3-Methoxy-1,4-cycloheptadien (22). 22 wird durch Isomerisierung von 3-Methoxy-1(Z).4(E)-cycloheptadien (30) gebildet, das wir in Form der Furan-Addukte 25 und 26 abfangen konnten. Wir nehmen an, daß 19 aus 5-Methoxy-1(Z),3(E)-cycloheptadien (31) durch intramolekulare Cyclisierung entsteht. Die Konfiguration von 19, 20, 25 und 26 spricht für den Angriff von Methanol auf das „halbgeöffnete“ Cyclopropyl-Kation 29. - Alle in CH3OD/HCO2Na gebildeten Produkte hatten etwa gleichen D-Gehalt. Die Stellung des Deuteriums in 17 zeigt, daß Doppelbindungsbeteiligung von 16 direkt zum 7-Norbornenyl-Kation 33 führt und das tricyclische Kation 32 nicht als Zwischenstufe auftritt. In Gegenwart von Lithiummethylat entstanden überwiegend die Produkte 17 und 18 aus dem 7-Norbornenyl-Kation 33, während 19-22 nun fehlten. Die Änderung der Produktverhältnisse wird durch die Carben-Umlagerung 38 → 41 erklärt, der sich eine Protonierung von 41 zu 33 anschließt.
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  • 82
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1895-1907 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Deamination Reactions, 32: Decomposition of Bicyclo[5.1.0]octa-2,4-diene-8-diazonium Ionsexo-Bicyclo[5.1.0]octa-2,4-diene-8-diazonium ions (11) have been generated from the corresponding nitrosourea (10) and base. In weakly alkaline solution the major products were derivatives of bicyclo[3.3.0]octadiene (12, 13) and 1(Z),3(Z),6(E)-cyclooctatriene (17). The reaction products and the distribution of a deuterium label in 12a, 13a suggest that 11 undergoes conrotatory transformation into the cyclooctatrienyl cation 24 as the first intermediate. In the presence of sodium methoxide, predominant formation of 8-syn-methoxybicyclo[3.2.1]octa-2,6-diene (18a) was observed. 8-Diazo-bicyclo[3.2.1]octa-2,6-diene (39) was generated from the tosylhydrazone 38 and excluded as an intermediate on the reaction path from 11 to 18. Most probably the carbon 1,3-shift proceeds as an interconversion of the carbenes 37 and 40.
    Notes: exo-Bicyclo[5.1.0]octa-2.4-dien-8-diazonium-Ionen (11) wurden durch alkalische Spaltung des entsprechenden Nitrosoharnstoffs (10) erzeugt. In schwach alkalischer Lösung entstanden als Hauptprodukte Derivate des Bicyclo[3.3.0]octadiens (12, 13) und des 1(Z),3(Z),6(E)-Cyclooctatriens (17). Die Reaktionsprodukte und die Verteilung einer D-Markierung in 12a, 13a weisen auf eine conrotatorische Umwandlung von 11 in das Cyclooctatrienyl-Kation 24 als erste Zwischenstufe hin. In Gegenwart von Natriummethylat wurde überwiegend 8-syn-Methoxybicyclo[3.2.1]-octa-2,6-dien (18a) gebildet. 8-Diazobicyclo[3.2.1]octa-2,6-dien (39) wurde aus dem Tosylhydrazon 38 erzeugt und als Zwischenstufe auf dem Weg von 11 zu 18 ausgeschlossen. Sehr wahrscheinlich erfolgt die 1,3-Kohlenstoffverschiebung als Umlagerung des Carbens 37 in 40.
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  • 83
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 431-438 
    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, XVI: Preparation of Esters of Dioxocarboxylic AcidsThiazolium salt catalysed addition of aldehydes to vinyl oxe-esters and of ester-aldehydes to vinyl ketones leads to esters of dioxocarboxylic acids.
    Notes: Unter Thiazoliumsalz-Katalyse werden Aldehyde an Vinylketoester und Esteraldehyde an Vinylketone unter Bildung von Diketocarbonsäureestern addiert.
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  • 84
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1938-1943 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Photochemically Induced Additions of Organic Disulfides to the Central Bond of a Bicyclo[1.1.0]butaneThe irradiation of an equimolar solution of an organic disulfide (5a-d) and of tricyclo[4.1.0.02,7]-heptane (4) yielded as the main product a stereoisomeric mixture of the bis-thioethers 7 and 8, accompanied by some sulfide 6. The latter compound was formed nearly exclusively if bulky substituents were fixed to the disulfide (5e,f).
    Notes: Die Bestrahlung einer äquimolaren Lösung eines organischen Disulfids (5a-d) und von Tricyclo-[4.1.0.02,7]heptan (4) lieferte als Hauptprodukt ein Stereoisomerengemisch der Bis-thioether 7 und 8, daneben in geringerer Ausbeute das Sulfid 6. Letzteres entstand nahezu ausschließlich, wenn am Disulfid sperrige Reste hafteten (5e,f).
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  • 85
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1958-1961 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Photoelectron Spectra and MNDO-Calculations for [n]ParacyclophanesThe observed splittings of the first two photoelectron bands and the calculated strain energies of the [n]paracyclophanes are discussed; a simple model suggests that they are mainly due to the deformation of the benzene ring. Energetic considerations lead to the conclusion that the “aromatic character” of the benzene moiety in the [n]paracyclophanes has been lost to a large extent for n = 6, and completely for n = 5.
    Notes: Die beobachteten Aufspaltungen der beiden ersten Photoelektronenbanden und die berechneten Spannungsenergien der [n]Paracyclophane werden diskutiert und in einem einfachen Modell vorwiegend auf die Deformation des Benzolrings zurückgeführt. Energetische Überlegungen führen zu dem Schluß, daß der „aromatische Charakter“ der Benzoleinheit in den [n]Paracyclophanen bei n = 6 weitgehend und bei = 5 vollständig verlorengegangen ist.
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  • 86
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 451-468 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Trinuclear Sandwich Compounds Containing Dialkylphosphonate as Bridging Ligands: Synthesis, NMR-, IR-, and Raman StudiesThe solvolysis of [C5H5Co{P(OR)2O}3BF]BF4 (3) leads to the half-sandwich complex [C5H5Co{P(O)(OR)2}2{P(OH)(OR)2}] (4). 4 is a novel O3-tripod ligand which reacts with the bivalent metalions M = Mg, Ca, Sr, Ba, Pb, Mn, Fe, Co, Ni, Cu, Zn, Cd, Hg to give the trinuclear compounds [{(C5H5)Co[P(O)(OR)2]2}2M] (5a-m). In these sandwich like complexes the dialkylphosphonate ligands are forming bridges of the type Co—(P—O)3—M—(O—P)3—Co between the three metal centers. The 1H NMR spectra are discussed. Due to a non-regular octahedral coordination of the central ion M = Cu and Hg the vP = O and δP = O bands in the IR spectra of 5j and 5m are split. It is shown by means of the IR spectra that the Jahn-Teller distorted octahedral coordination of CuII in 5j is changed to a regular one under the influence of high pressure (35 kbar).
    Notes: Es wird über die Synthese des Halbsandwichkomplexes [C5H5Co{P(O)(OR)2}2{P(OH)(OR)2}] (4) aus [C5H5Co{P(OR)2O}3BF]BF4 (3) berichtet. 4 ist ein neuartiger O3-Tripodligand, der mit den zweiwertigen Metall-Ionen M = Mg, Ca, Sr, Ba, Pb, Mn, Fe, Co, Ni, Cu, Zn, Cd, Hg zu dreikernigen Verbindungen der Zusammensetzung [{(C5H5)Co[P(O)(OR)2]3}2M] (5a-m) reagiert. In den sandwich-artigen Komplexen 5 bilden die Dialkylphosphonatliganden Brücken der Art Co—(P—O)3—M—(O—P)3—Co zwischen den drei Metallzentren. Die 1H-NMR-Spektren werden diskutiert. Im IR-Spektrum beobachtet man als Folge der nicht regulären Oktaederkoordination beim CuII-Komplex 5j und bei der Quecksilberverbindung 5m eine Aufspaltung der VP = O und δP = O-Banden. An Hand der IR-Spektren wird gezeigt, daß die Jahn-Teller-Verzerrung des CuII-Komplexes 5j unter einem Druck von 35 kbar aufgehoben werden kann.
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  • 87
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1989-1997 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Ring Contraction of 5,6-Dihydro-2H-1,2,3,6-thiatriazine 1-Oxides into Δ3-1,2,3-Thiadiazoline Derivatives; X-Ray Analysis of 2,4-Dimethyl-5-tosylimino-Δ3-1,2,3-thiadiazoline5,6-Dihydro-2H-1,2,3,6-thiatriazine 1-oxides 1a-d rearrange in the presence of trifluoroacetic acid to give 2,4,5,6,7,7a-hexahydro-1,2,3-benzothiadiazole 1-oxides 2a, b and Δ3-1,2,3-thiadiazoline 1-oxides 2c, d, respectively. On treatment with trifluoroacetic acid, at C-5 unsubstituted 5,6-dihydro-2H-1,2,3,6-thiatriazine 1-oxides 1e and f, however, yield Δ3-1,2,3-thiadiazolines 4e and f, respectively, by loss of H2O. Two reaction pathways are suggested for the formation of the ring contraction products. The structure of 4e was confirmed by X-ray analysis.
    Notes: Die 5,6-Dihydro-2H-1,2,3,6-thiatriazin-1-oxide 1a-d lagern in Gegenwart von Trifluoressigsäure in die 2,4,5,6,7,7a-Hexahydro-1,2,3-benzothiadiazol-1-oxide 2a, b bzw. in die Δ3-1,2,3-Thiadiazolin-1-oxide 2c, d um. Die an C-5 unsubstituierten 5,6-Dihydro-2H-1,2,3,6-thiatriazin-1-oxide 1 e und f führen mit Trifluoressigsäure dagegen unter Abspaltung von H2O zu den Δ3-1,2,3-Thiadiazolinen 4e bzw. f. Für die Bildung der Ringverengungsprodukte werden zwei Reaktionswege vorgeschlagen. Die Struktur von 4e wurde durch Röntgenanalyse bestätigt.
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2003-2009 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Reaction of β-Aminovinylcarbonyl Compounds with DiphenylcarbodiimideThe cyclization of 3-amino-2-alkylpropenals 1 with diphenylcarbodiimide (2) yields 5-alkyl-1-phenylpyrimidin-2(1H)-phenylimines 4. No corresponding reaction is observed with dicyclo-hexylcarbodiimide. 4-Amino-3-penten-2-one (5) reacts with diphenylcarbodiimide (2) as a CH acidic compound, i.e. involving addition to 4-amino-3-(N,N′-diphenylamidino)-3-penten-2-one (7). The corresponding addition to ethyl β-aminocrotonate (6) is observed to give 8. The constitution of the products 4, 7, and 8 is in accordance with the IR-, 1H- and 13C NMR spectra.
    Notes: 3-Amino-2-alkylpropenale 1 cyclisieren mit Diphenylcarbodiimid (2) zu 5-Alkyl-1-phenyl-pyrimidin-2(1H)-phenyliminen 4. Mit Dicyclohexylcarbodiimid wird keine entsprechende Reaktion beobachtet. 4-Amino-3-penten-2-on (5) reagiert mit Diphenylcarbodiimid (2) wie eine CH-acide Verbindung, d. h. unter Addition zu 4-Amino-3-(N,N′-diphenylamidino)-3-penten-2-on (7). Die entsprechende Addition zu 8 wird auch für β-Aminocrotonsäure-ethylester (6) beobachtet. Die Konstitution der Verbindungen 4, 7 und 8 stimmt mit den IR-, 1H- und 13C-NMR-Spektren überein.
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2010-2020 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Barriers to Hindered Rotation Around the N-Glycosidic Bond, II: 1-(α-D-Mannopyranosyl)isocyanuric AcidsSyntheses of the 1-(α-D-mannopyranosyl)isocyanuric acids 2a--c and 3 are reported. According to the 1H-NMR spectra these compounds form in solution dynamic equilibria of flexible conformations (oS2) with pseudoequatorial aglyca. For the tetra-O-acetyl compound 2b an X-ray analysis has been performed (orthorhombic P212121; R-value 0.057). In the crystalline state 2b has 4C1 conformation, flattened at the C1′-end, with axial aglycon. The isocyanuric acid ring is almost perpendicular to the C1′ - O5′ bond and is partly lying under the sugar ring. The barrier to hindered rotation around the N-glycosidic bond of 2b as determined by 13C-NMR spectroscopy in solution is ΔG198≠ = 41.8 ± 1.3 kJmol-1. This barrier is considerably lower than the corresponding barrier of 1-(β-D-glucopyranosyl)isocyanuric acids2).
    Notes: Es werden Synthesen der 1-(α-D-Mannopyranosyl)isocyanursäuren 2a-c und 3 beschrieben. Nach den 1H-NMR-Spektren liegen die Verbindungen in Lösung in dynamischen Gleichgewichten flexibler Konformationen (oS2) mit pseudoäquatorialem Aglycon vor. Die Tetra-O-acetyl-Verbindung 2b wurde einer Röntgenstrukturanalyse unterworfen (orthorhombisch P212121; R-Wert 0.057). Im Kristall hat 2b eine am C1′-Ende abgeflachte 4C1-Sesselkonformation mit axialem Aglycon. Der Isocyanursäurering steht nahezu senkrecht auf der Bindung C1′ - O5′ und liegt damit teilweise unter dem Zuckerring. Die in Lösung mittels 13C-NMR-Spektroskopie gemessene Barriere der behinderten Rotation um die N-glycosidische Bindung von 2b beträgt ΔG198≠ = 41.8 ± 1.3 kJmol-1 und ist damit erheblich niedriger als die entsprechende Barriere der 1-(β-D-Glucopyranosido)isocyanursäuren2).
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  • 90
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2037-2046 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Crystal Structure Determination of (N′N′-Dimethylhydrazino)triphenylphosphonium Bromide by X-Ray TechniqueThe structure of the title compound has been determined by X-ray cristal structure analysis and was refined to R = 0.049 (Rw = 0.041). The P—N bond distance and the geometry of the nitrogen in α-position were compared with structurally analogous phosphor nitrogen compounds. The bond distance, which is relatively short for a P—N single bond, gives an explanation for the known reactions of the hydrazinophosphonium salts with nitrosation reagents.
    Notes: Die Kristallstruktur der Titelverbindung wurde röntgenographisch bestimmt und bis zu einem R-Faktor von 0.049 (Rw = 0.041) verfeinert. Der P—N-Bindungsabstand und die Geometrie am α-ständigen Stickstoffatom werden mit struktur-ähnlichen Phosphorstickstoff-Verbindungen verglichen. Der für eine P—N-Einfachbindung relativ kurze Abstand ist eine Erklärung für die bekannten Umwandlungen der Hydrazinophosphonium-Salze mit Nitrosierungsreagenzien.
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  • 91
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reactions of Complex Ligands, XI: Stereoselectivity of the Insertion of Ynamines into the Chromium Carbene Bond: First Step of a Two-Step Synthesis of Indanone and Indenone DerivativesPentacarbonyl[methoxymethyl(or phenyl)carbene]chromium (1, 2) reacts with 1-(dialkylamino)-acetylenes (3, 4) in a stereoselective way to give E- and Z-pentacarbonyl(alkenylaminocarbene)-chromium complexes (5-7) via insertion of the alkyne into the metal-carbene bond. The thermolysis of pentacarbonyl[(diethylamino)-E-(β-methoxy-α-methylstyryl)carbene]chromium (7a) in n-decane results in the formation of the tricarbonylchromium complexes of 2-methyl-1-indenone (8) and trans-3-methoxy-2-methyl-1-indanone (9).
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  • 92
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Oxidative Addition of Hexafluoroacetone and Hexafluorobiacetyl to Phosphorus(III) Fluorides RR′PF: Synthesis of Chiral 1,3,2-Dioxaphospholanes and 1,3,2-DioxaphospholenesHexafluoroacetone and hexafluorobiacetyl react with fluorophosphines and fluorophosphites in an oxidative addition to form stable cyclic oxyphosphoranes containing the 1,3,2-dioxaphospholane (2) or 1,3,2-dioxaphospholene ring system (3). 19F and 31P NMR spectra are reported. The temperature dependency of the 19F NMR spectra in the range between -90 and +110°C is discussed in the light of pseudorotation processes at phosphorus(V).
    Notes: Hexafluoraceton und Hexafluorbiacetyl reagieren mit Fluorphosphinen und Fluorphosphiten unter Bildung stabiler cyclischer Oxyphosphorane mit dem 1,3,2-Dioxaphospholan- (2) bzw. Dioxaphospholen-Ringsystem (3). 19F- und 31P-NMR-Spektren werden mitgeteilt. Die Temperaturabhängigkeit der 19F-NMR-Spektren im Bereich von -90 bis +110°C wird auf der Basis von Pseudorotationsprozessen am Phosphor(V) diskutiert.
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  • 93
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2108-2112 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Addition of Diborontetrahalides to Unsaturated HydrocarbonsB2Cl4 and B2F4 add on the C = C-bond of methylenecyclopropane or vinylcyclopropane forming the diboryl compounds 3 and 5 respectively, C—C-bonds of the cyclopropane rings are not cleaved even using an excess of B2Cl4. The properties of the new compounds and their spectroscopic data are listed.
    Notes: B2Cl4 und B2F4 addieren sich an die C = C-Bindung von Methylencyclopropan bzw. Vinylcyclopropan unter Bildung der Diborylverbindungen 3 bzw. 5. C—C-Bindungen der Cyclopropanringe werden auch bei einem Überschuß von B2Cl4 nicht gespalten. Die Eigenschaften der neuen Verbindungen und ihre spektroskopischen Daten sind aufgeführt.
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  • 94
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2123-2129 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation and Some Properties of Silyl Derivatives of 2-Tetrazene and -Pentazene (Attempts for the Preparation of cis-2-Tetrazene and -Pentazene)Oxidation of [(Me3Si)2N2Li]2SiMe2 (2) with benzenesulfonyl azide or ethyl nitrite yields a cyclic silyltetrazene (4) and -pentazene (6), respectively. Thermolysis of 4 causes ring opening and formation of (Me3Si)2NSiMe2N3 (9), whereas thermolysis of 6 leads to ring reorganisation with formation of the heterocycle 10a. Protolysis of 4 with trifluoroacetic acid gives ammonium azide  -  possibly via cis-2-tetrazene  - , protolysis of 6 yields nitrogen, ammonia, hydrazine, and hydrazoic acid  -  possibly via pentazene.
    Notes: Aus [(Me3Si)2N2Li]2SiMe2 (2) entsteht durch Oxidation mit Benzolsulfonylazid bzw. Ethylnitrit ein cyclisches Silyltetrazen (4) bzw. Silylpentazen (6. 4 thermolysiert unter Ringöffnung zu (Me3Si)2NSiMe2N3 (9), 6 unter Ringumlagerung zum Heterocyclus 10a. Die Protolyse mit Trifluoressigsäure führt im Falle von 4  -  möglicherweise über cis-2-Tetrazen  -  zum Ammoniumazid, im Falle von 6  -  möglicherweise über Pentazen  -  zu Stickstoff, Ammoniak. Hydrazin und Stickstoffwasserstoffsäure.
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  • 95
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2173-2178 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Mesoinoic Six-membered Heterocycles, X: Synthesis and Reactions of Mesoionic 1,2,3-TriazinesThe reaction of (chloroformyl)ketenes 2 with triazenes 3 in ether yields mesoionic 1,2,3-triazines 4. The structure of these compounds is substantiated by solvolysis and hydrogenation reactions. At 140°C compound 4a looses azobenzene (9) and nitrogen to give the 3,3′-biazetidinetetraone 8.
    Notes: Die Reaktion der (Chlorformyl)ketene 2 mit Triazenen (3) in Ether liefert mesoionische 1,2,3-Triazine (4). Die Struktur dieser Verbindungen wird durch Solvolysereaktionen sowie katalytische Hydrierungen gestützt. Die Verbindung 4a reagiert bei 140°C unter Verlust von Azobenzol (9) und Stickstoff zum 3,3′-Biazetidintetraon 8.
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  • 96
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2199-2205 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stereochemistry of Metal-Metal Bonds: Crystal Structure of Cr2(CO)7(C5H5)As(CH3)2The crystal structure of the title complex 1 has been determined. Crowding of ligands in the molecule results in the very long Cr—Cr bond distance of 319 pm. A comparison with the structures of related complexes of manganese and iron shows the systematic influence of the number of ligands on the metal-metal bond lengths.
    Notes: Die Kristallstruktur des Titel-Komplexes 1 wurde bestimmt. Häufung von Liganden im Molekül bewirkt den mit 319 pm sehr großen Cr—Cr-Bindungsabstand. Ein Vergleich mit den Strukturen verwandter Komplexe des Mangans und Eisens belegt den systematischen Einfluß der Ligandenzahl auf die Metall-Metall-Bindungslängen.
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  • 97
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2258-2266 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 3-Diazoindazoles: Photochemistry, Thermochemistry, CycloadditionsOn photolysis or thermolysis the 3-diazoindazole 1 a eliminates nitrogen with formation of the carbene 2. This rearranges via a nitrene intermediate 3 to the azo-compound 6. In the presence of electron-rich olefines and alkynes the 3-diazoindazoles 1 react also as dipoles with inverse electron demand affording triazino-indazoles 9.
    Notes: Die Photolyse oder Thermolyse des 3-Diazoindazols 1 a liefert unter Stickstoffabspaltung das Carben 2, das sich über eine Nitrenzwischenstufe 3 unter Bildung der Azoverbindung 6 stabilisiert. Weiterhin stellen die 3-Diazoindazole 1 Dipole mit inversem Elektronenbedarf dar, die mit elektronenreichen Alkinen bzw. Olefinen in einer neuen Reaktion die Triazino-indazole 9 liefern.
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  • 98
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    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2267-2272 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Complex-bound Carbene Analogues, II: Synthesis and Vibrational Spectra of Pentacarbonyl[chloro(di-tert-butylphosphino)stannio]-metal(VI A) ComplexesThe tindichloride complexes pentacarbonyl(dichlorotetrahydrofurane-stannio)chromium(0) (1), -molybdenum(0) (2) and -tungsten(0) (3) react with di-tert-butyl(trimethylsilyl)phosphine with elimination of tetrahydrofurane and formation of chlorotrimethylsilane to give the new, base free stannio complexes (CO)5M—Sn(Cl)[P(tBu)2] (4-6: M = Cr, Mo, W) with 75 to 85% yield. The ligand properties of chloro(di-tert-butylphosphino)-stannandiyl (-stannylene) are discussed on the basis of infrared and Raman data, and other physical properties.
    Notes: Die SnCl2-Metallkomplexe Pentacarbonyl(dichlortetrahydrofuran-stannio)chrom(0) (1), -molybdän(0) (2) und -wolfram(0) (3) reagieren mit Di-tert-butyl(trimethylsilyl)phosphin unter Verdrängung von Tetrahydrofuran und Eliminierung von Chlortrimethylsilan, wobei die neuen basenfreien Stannylenkomplexe (CO)5M—Sn(Cl)[P(tBu)2] (4-6: M = Cr, Mo, W) in 75-85 proz. Ausbeute erhalten werden. Die Ligandeneigenschaften von Chlor(di-tert-butylphosphio)stanandiyl (-stannylen) werden anhand von IR- und Raman-Daten sowie der physikalischen Eigenschaften von Ligand und Komplexen diskutiert.
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  • 99
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2290-2296 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Investigations on Diazo Compounds and Azides, XXX: C-Alkylation of (Diazomethyl)phosphoryl Compounds with EnaminesThe phosphoryl diazomethanes 1a and b react with the enamines 2a-d to form the β-amino-α-diazophosphoryl compounds 3a-f. Addition of perchloric acid and hydrogen chloride, respectively, yields the ammonium salts 4a-f. It seems to be plausible, that the alkylation reaction proceeds via the intermediates 5 and 7.
    Notes: Die Phosphoryldiazoalkane 1a und b reagieren mit den Enaminen 2a-d zu den β-Amino-α-diazophosphorylverbindungen 3a-f. Addition von Perchlorsäure bzw. Chlorwasserstoff liefert die Ammoniumsalze 4a-f. Es erscheint plausibel, daß die Alkylierungsreaktion über die Zwischenstufen 5 und 7 verläuft.
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  • 100
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2307-2319 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Synthesis of the Tetracyclo[4.1.0.02,4.03,5]heptane System by Addition of Halogen-Substituted Carbenes to BenzvaleneDibromo-, dichloro-, difluoro-, chlorofluoro-, and chlorocarbene react with benzvalene (1) to give the corresponding 7-substituted tetracyclo[4.1.0.02,4.03,5]heptanes 2a-g, thus providing the first and simultaneously productive access to this highly strained ring system. With the exception of fluorine the halogen atoms are easily replaced by hydrogen, which results in a second mode of preparation of 7-endo-(2g) and 7-exo-monochlorotetracycloheptane (2f) and which also yields both of the monofluoro (2k, l) and monobromo derivatives (2h, i). Furthermore by this reaction the unsubstituted hydrocarbon 2m can be obtained in synthetically useful quantities. Under the catalysis of silver tetrafluoroborate 2m rearranges exothermally to cycloheptatriene. Likewise the dideuterio derivative 2n is transformed to 3,4-dideuteriocycloheptatriene (7a) free of isomers. The 1H and 19F NMR spectra reveal the outstanding ability of the tetracycloheptane skeleton to bring about long range coupling. Direct interactions through space are considered in the case of J4,7endo.
    Notes: Aus der Addition von Dibrom-, Dichlor-, Difluor-, Chlorfluor- und Chlorcarben an Benzvalen (1) gehen die entsprechenden 7-substituierten Tetracyclo[4.1.0.02,4.03,5]heptane 2a-g hervor. Ihr hochgespanntes Ringsystem erhält damit den ersten und gleichzeitig ergiebigen Zugang. Mit Ausnahme von Fluor lassen sich die Halogenatome leicht durch Wasserstoff ersetzen, wodurch 7-endo- (2g) und 7-exo-Monochlortetracycloheptan (2f) einen zweiten Syntheseweg erhalten, jeweils die beiden Monofluor- und Monobromderivate 2k und 1 bzw. 2h und i darstellbar sind und schließlich der unsubstituierte Grundkörper 2m in präparativ brauchbaren Mengen bereitet werden kann. 2m lagert unter Silber(I)-Ionen-Katalyse exotherm im Cycloheptatrien um; aus dem Dideuterioderivat 2n entsteht analog isomerenfreies 3,4-Dideuteriocycloheptatrien (7a). Die 1H- und 19F-NMR-Spektren enthüllen die vorzügliche Eignung des Tetracycloheptangerüsts zur Vermittlung von Fernkopplungen. Direkte Wechselwirkungen durch den Raum werden im Falle von J4,7endo in Betracht gezogen.
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