aldehyde addition was investigated in detail by stoichiometric and catalytic experiments as well as NMR spectroscopic measurements. The primary reaction product of the addition of the SiB reagent and the aldehyde (a boric acid ester of the α‐silyl alcohol) and also the “dead‐end” intermediate, formed in the competing [1,2]‐Brook rearrangement, were characterized crystallographically. Based on these data
SiB元素间键与醇
铜(I)的活化产生
铜基
硅亲核试剂,该亲核试剂在
水解后易于与醛反应生成α-
硅醇(即α-羟基
硅烷)。两个独立的协议被开发,一个使用良好定义的NHC 的CuO吨卜复杂和使用无添加的
配体的简单的CuCN-的NaOMe的组合的一个。通过
化学计量和催化实验以及NMR光谱测量详细研究了醛的加成机理。Si添加的主要反应产物B试剂和醛(α-
硅醇的
硼酸酯)以及竞争的[1,2] -Brook重排中形成的“死端”中间体在结晶学上得到了表征。基于这些数据,提出了合理的催化循环。所述NHC 的CuO吨在升高的温度下催化卜设置进行很好。CuCN-NaOMe产生了更具反应性的催化系统,在明显较低的温度下显示出快速的周转率。在这些温和的反应条件下,芳族和脂族醛均以良好或非常高的收率转化为相应的α-甲
硅烷基醇。