The<b><i>γ</i></b>-Silicon Effect. I. Solvent Effects on the Solvolyses of 2,2-Dimethyl-3-(trimethylsilyl)propyl and 3-(Aryldimethylsilyl)-2,2-dimethylpropyl<b><i>p</i></b>-Toluenesulfonates
作者:Tohru Nakashima、Ryoji Fujiyama、Mizue Fujio、Yuho Tsuno
DOI:10.1246/bcsj.72.741
日期:1999.4
The solvolysis rates of 2,2-dimethyl-3-(trimethylsilyl)propyl and 3-(aryldimethylsilyl)-2,2-dimethylpropyl p-toluenesulfonates were measured in a wide variety of solvents at 45 °C. The solvent effects were analyzed by using the Winstein–Grunwald equation. The solvent effects observed did not give simple linear correlations with the 2-adamantyl YOTs parameter, but showed dispersion behavior in a series
2,2-二甲基-3-(三甲基甲硅烷基)丙基和3-(芳基二甲基甲硅烷基)-2,2-二甲基丙基对甲苯磺酸酯的溶剂分解速率在45°C下在多种溶剂中测量。使用 Winstein-Grunwald 方程分析溶剂效应。观察到的溶剂效应与 2-金刚烷基 YOT 参数没有给出简单的线性相关性,但在一系列二元溶剂中表现出分散行为。对于 2-金刚烷基对甲苯磺酸酯的极限 kc 溶剂分解,0.59-0.67 的 m 值显着低于 1。无法根据溶剂的亲核辅助来解释偏差模式。发现 3-(芳基二甲基甲硅烷基)衍生物的 m 值降低时的分散行为比 3-(三甲基甲硅烷基)衍生物更显着,并且与 Si-Cγ 键参与的初始阳离子电荷的离域相容速率决定步骤。扩展的双参数处理,log (k/k80E) = mcYOTs + mΔYΔ,successf...