Rates and Mechanism for the Solvolyses of 2,2-Dimethyl-2-sila-1-indanyl Bromide and α-Trialkylsilylbenzyl<i>p</i>-Toluenesulfonates. α-Silicon Effect on the Stability of Benzylic Cations in Solution
作者:Nobujiro Shimizu、Erika Osajima、Yuho Tsuno
DOI:10.1246/bcsj.64.1145
日期:1991.4
solvolysis has been investigated. The solvolysis of 2,2-dimethyl-2-sila-1-indanyl bromide in aq acetone exhibits a linear response to the solvent ionizing power YBr with a slope m close to unity (m=0.93) and gives the corresponding alcohol without skeletal rearrangement indicative of a kc mechanism; it solvolyzes 4.98×102 times less rapidly than a carbon reference, 2,2-dimethyl-1-indanyl bromide, in 60% aq
已经研究了α-硅对苄基溶剂分解的影响。2,2-二甲基-2-硅-1-茚满基溴在丙酮水溶液中的溶剂分解对溶剂电离能力 YBr 呈线性响应,斜率 m 接近于 1 (m = 0.93),并得到相应的醇而没有骨架重排指示kc机制;它在 60% 丙酮水溶液中于 25°C 的溶剂分解速度比碳参照物 2,2-二甲基-1-茚满基溴的速度低 4.98 × 102 倍,这表明 α-甲硅烷基化苄型阳离子的溶剂分解产生电子约 4 kcal mol -1 不如相应的 α-烷基化苄型阳离子。由于额外的空间效应,在开放苄基体系的溶剂分解中观察到 α-SiMe3 基团相对于 Me 的 1.65×104 的更显着的速率延迟。