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  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 109 (1976), S. 2728-2742 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Dyotropic Rearrangements, VIII: Mechanism of the Rearrangement of (Silyl)methyl silyl EthersThe mechanism of the degenerate dyotropic valence isomerization of (silyl)methyl silyl ethers 1 ⇄ 2 has been investigated with the aid of cross-over and trapping experiments, activation parameters, solvent dependency, and substituent effects. The configuration at a chiral silyl group is retained during the rearrangement. Several mechanisms are discussed, of which a dyotropic, i. e., concerted process with an asymmetric transition state is preferred.
    Notes: Der Mechanismus der entarteten dyotropen Valenzisomerisierung von (Silyl)methyl-silyl-äthern 1 ⇄ 2 wird anhand von Kreuzungs und Abfangversuchen, Aktivierungsparametern, Lösungsmitteleinflüssen und Substituenteneffekten untersucht. Die Konfiguration an einer chiralen Silyl-gruppe bleibt während der Umlagerung erhalten. Mehrere Mechanismen werden diskutiert, wobei einem dyotropen bzw. konzertierten prozeß mit asymmetrischem Übergangszustand der Vorrang gegeben wird.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 2958-2959 
    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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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 808-810 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Anchimerically Enhanced Homolyses, V. Fluoride Ion Catalysed Rearrangements of Benzyl 9-(Trimethylgermyl)-9-fluorenyl EtherThe thermal rearrangement (homolysis) of the germanium compound 1d into 4d is considerably slower than that of the analogous Si compound 1c. Thus, a correlation is suggested between the velocity of the rearrangement and the strength of the new bond to oxygen. The rearrangement 1d→4d is also induced by fluoride ions at room temperature.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1083-1094 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Anchimerically Accelerated Homolyses, II: Synthesis, Thermolysis, and Photolysis of Alkyl (Silylmethyl) EthersAlkyl(silylmethyl) ethers 11a-f were synthesized in order to observe a thermal rearrangement to 12a-f, in which the alkyl and silyl groups exchange their positions. Thermolysis does indeed induce the desired rearrangement in all cases with the exception of 11e and 11f. In line with the assumption that the reaction proceeds with anchimeric assistance from the silyl group, only those compounds rearrange which potentially liberate resonance stabilized radicals. The activation parameters are discussed. Photolysis of 11c does not afford the thermal rearrangement product 12c.
    Notes: Alkyl-(silylmethyl)-ether 11a-f wurden synthetisiert, um eine thermische Umlagerung zu 12a-f beobachten zu können, bei der die Alkyl- und Silylgruppen ihre Plätze vertauschen. Die Thermolyse löst tatsächlich in allen Fällen die gewünschte Umlagerung aus, mit Ausnahme von 11e und 11f. In Übereinstimmung mit der Vermutung, daß die Reaktion radikalisch mit anchimerer Unterstützung durch die Silylgruppe verläuft, lagern nur solche Verbindungen um, die potentiell resonanzstabilisierte Radikale liefern. Die Aktivierungsparameter werden diskutiert. Die Photolyse von 11c ergibt nicht das thermische Umlagerungsprodukt 12c.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1095-1107 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Anchimerically Accelerated Homolyses, III: Mechanism of the Thermal Rearrangement of Alkyl (Silylmethyl) EthersThe mechanism of the thermal rearrangement of alkyl (silylmethyl) ethers 1 → 2 has been investigated with the help of crossover and radical trapping experiments, solvent and substituent effects, and ESR studies. Homolysis with anchimeric participation of the silyl group appears to be operating. Migration of the silyl group toward the oxygen atom initiates the reaction, whereby the strong Si—O bond and resonance stabilized ketyl and alkyl radicals are formed. Comparisons with the few previously known examples of anchimeric effects in unimolecular homolyses are made.
    Notes: Der Mechanismus der thermischen Umlagerung von Alkyl-(silylmethyl)-ethern 1 → 2 wurde mit Hilfe von Kreuzungs- und Radikalabfangversuchen. Lösungsmitteleinflüssen. Substituenteneffekten und ESR-Studien untersucht. Dabei zeigt sich, daß eine Homolyse unter anchimerer Beteiligung der Silylgruppe wahrscheinlich ist. Die Wanderung des Silylrestes zum Sauerstoff leitet die Reaktion ein, wobei die starke Si—O-Bindung und resonanzstabilisierte Ketyl- und Alkylradikale gebildet werden. Vergleiche mit den wenigen, in der Literatur bislang bekannten Beispielen für anchimere Effekte bei unimolekularen Homolysen werden angestellt.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 89 (1977), S. 765-766 
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 0570-0833
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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