Silylium‐Ion‐Promoted (5+1) Cycloaddition of Aryl‐Substituted Vinylcyclopropanes and Hydrosilanes Involving Aryl Migration
作者:Tao He、Guoqiang Wang、Vittorio Bonetti、Hendrik F. T. Klare、Martin Oestreich
DOI:10.1002/anie.202004320
日期:2020.7.13
A transition‐metal‐free (5+1) cycloaddition of aryl‐substituted vinylcyclopropanes (VCPs) and hydrosilanes to afford silacyclohexanes is reported. Catalytic amounts of the trityl cation initiate the reaction by hydride abstraction from the hydrosilane, and further progress of the reaction is maintained by self‐regeneration of the silylium ions. The new reaction involves a [1,2] migration of an aryl
据报道,芳基取代的乙烯基环丙烷(VCP)和氢硅烷可进行无过渡金属(5 + 1)环加成反应,得到硅环己烷。催化量的三苯甲基阳离子通过从氢化硅烷中夺取氢化物来引发反应,并通过硅离子的自我再生来保持反应的进一步进展。新的反应涉及芳基的[1,2]迁移,最终提供4取代3取代的芳基硅烷环己烷衍生物作为主要产物。各种控制实验和量子化学计算都支持了一种机理图,其中通过环丙烷环分子内稳定的甲硅烷基离子可以进行动力学上有利的协同[1,2]芳基迁移/环扩展或参与环丙烷-环丙烷重排。