Mechanistic Variations in Ionic Hydrogenation of Unsaturated Phosphine and Amine Boranes
作者:Timothy S. De Vries、Supriyo Majumder、Angela M. Sandelin、Guoqiang Wang、Edwin Vedejs
DOI:10.1021/ol2031203
日期:2012.2.3
Internal hydride transfer occurs when tethered carbocations are generated from unsaturated phosphine or phosphinite boranes. 3-Methylenecyclohexyl-derived boranes 12 or 18 react with MsOH to give ionic hydrogenation products with high syn-selectivity. With unsaturated amine boranes, initial hydrogen evolution gives BH2(OMs) complexes, but IH occurs using excess MsOH in a slower second stage. A diastereoselective
当不饱和膦或次膦酸硼烷生成束缚碳正离子时,会发生内部氢化物转移。3-亚甲基环己基衍生的硼烷12或18与 MsOH 反应得到具有高顺选择性的离子氢化产物。对于不饱和胺硼烷,初始析氢产生 BH 2 (OMs) 配合物,但 IH 在较慢的第二阶段使用过量的 MsOH 发生。使用樟脑磺酸(第一阶段)和 MsOH(第二阶段)从26b发生非对映选择性反应,水解后得到 33(68% ee)。