constitutional isomers. The reaction proceeded through two consecutive dehydrogenative silylations, and the absolute configuration was determined in the first silylative cyclization. Competitive reactions with electron‐rich and electron‐deficient dihydrosilanes indicated that the rate of silylative cyclization increased with decreasing electron density on the silicon atom of the starting dihydrosilane. Further
据报道,通过
铑催化的脱氢甲
硅烷基化反应合成螺-9-
硅双
芴,从而构建了季
硅手性中心的机理。的Ç 2对称的双
膦配体BINAP可有效控制对映体选择性,并且以优异的收率和高对映体过量获得了轴向手性螺9-9
硅芴。对该反应的监测表明,存在作为两种结构异构体的混合物的一氢
硅烷中间体。反应进行两次连续的脱氢甲
硅烷基化,并在第一次甲
硅烷基化环化反应中确定绝对构型。与富电子和缺电子的二氢
硅烷的竞争反应表明,甲
硅烷基化的速率随起始二氢
硅烷的
硅原子上电子密度的降低而增加。