The gas-phase protonation of vinyltrimethylsilane was carried out, using γ -radiolysis of methane. The ionic species, involved in the process, were trapped by nucleophilic attack of methanol.
Kinetic studies on the aminolysis of 1-(trimethylsilyl)ethyl arenesulphonates in acetonitrile and methanol
作者:Hyuck Keun Oh、Chul Ho Shin、Hyoung Yeon Park、Ikchoon Lee
DOI:10.1002/poc.610070705
日期:1994.7
Nucleophilicsubstitutionreactions of 1-(trimethylsilyl)ethyl arenesulphonates with anilines and benzylamines in acetonitrile and methanol at 65·0°C were studied. The cross-interactionconstants, ρXZ, between substituents in the nucleophile (X) and leaving group (Z) are relatively small (0·10 for XC6H4NH2 in MeCN) but similar to those for other SN2 processes at a secondary carbon atom. This provides
研究了在65·0℃条件下,1-(三甲基甲硅烷基)乙基芳磺酸酯与苯胺和苄胺在乙腈和甲醇中的亲核取代反应。亲核试剂(X)中的取代基与离去基团(Z)之间的交叉相互作用常数ρXZ相对较小(MeCN中的XC 6 H 4 NH 2为0·10 ),但与其他S N 2过程在仲碳原子。这提供了进一步的证据为大致恒定的,松散小号Ñ在仲碳2的过渡态而不管C的尺寸的α取代基。带有取代基X和Z的过渡态变化与所观察到的正ρXZ值相符:亲核体和/或亲核试剂越强,过渡态越早,即键形成和断裂的程度越低。
Kinetics and mechanisms of .alpha.- and .beta.-eliminations of alkoxysilanes from saturated and unsaturated carbon frameworks
作者:Sukhamaya. Bain、Sina. Ijadi-Maghsoodi、Thomas J. Barton
DOI:10.1021/ja00216a039
日期:1988.4
favorable elimination of Me/sub 3/SiOMe from Me/sub 3/SiSiMe/sub 2/CH/sub 2/OMe does not occur. From kinetic studies and trapping experiments, this is found to be due to a more favorable A-factor for three-centeredelimination of :CH/sub 2/. Three-centeredelimination of Me/sub 3/SiOMe from an sp/sup 2/-hybridized carbon to afford a vinylidene is found to be more facile than the analogous elimination from