Investigation of the factors controlling the regioselectivity of the hydrosilylation of alkynes catalysed by trans-di-μ-hydridobis(tricylcohexylphosphine)bis(silyl)diplatinum complexes
作者:Constantinos A. Tsipis
DOI:10.1016/s0022-328x(00)93435-1
日期:1980.3
The hydrosilylation of terminal and internal alkynes and also of some hydroxy-alkynes catalysed by trans-di-μ-hydridobis(tricyclohexylphosphine)bis(silyl)diplatinum complexes is described. These diplatinum complexes are very efficient catalysts for such hydrosilylations; high yields (80–98%) can be obtained under mild conditions with a catalysts/reactant ratio of 10−4–10−5/1. Addition of hydrosilanes
描述了末端和内部炔烃的氢化硅烷化,以及通过反式-di-氢化双(三环己基膦)双(甲硅烷基)二铂配合物催化的一些羟基炔烃的氢化硅烷化。这些二铂配合物是用于这种氢甲硅烷基化的非常有效的催化剂。在温和的条件下,催化剂/反应物之比为10 -4 -10 -5 / 1时,可以获得高收率(80-98%)。含氢硅烷X的另外3的SiH的炔烃RCCH,RCCR和RCCR'前进以顺式方式得到反式-RCHCHSiX 3,顺式-RC(SIX 3)CHR和区域异构体的混合物ë - RC(SiX 3)CHR'和E- RCHC(SiX 3)R'。在末端炔烃的情况下,还形成了少量的对应于氢化硅烷的Markownikow加成的内部加合物。评估了反应条件的变化(反应物或催化剂的浓度和温度)对添加速率和区域选择性的影响。炔基π键的电子密度的不对称性越高,区域选择性越高。根据对炔烃插入PtH键的步骤中形成的过渡态的定性分子轨道处理,来解释区域选择性。