Catalytic Enantioselective Allylation of Dienals through the Intermediacy of Unsaturated π-Allyl Complexes
作者:Ping Zhang、James P. Morken
DOI:10.1021/ja9058537
日期:2009.9.9
nickel-catalyzed enantioselective addition of allylboronic acid pinacol ester [allylB(pin)] to alpha,beta,gamma,delta-unsaturated aldehydes is described. This reaction results in a remarkable inversion of substrate olefin geometry, providing the Z,E-configured reaction product in good enantioselectivity and olefin stereoselectivity. The reaction appears to proceed by conversion of the dienal to an unsaturated
描述了镍催化对映选择性添加的烯丙基硼酸频哪醇酯 [allylB(pin)] 到 α、β、γ、δ 不饱和醛。该反应导致底物烯烃几何结构的显着反转,提供具有良好对映选择性和烯烃立体选择性的 Z,E 构型反应产物。该反应似乎是通过将二烯醛转化为不饱和的 pi-烯丙基络合物,然后通过过渡态 II 进行还原消除来进行的。当使用手性配体 L3 时,一系列 delta 取代的二烯醛的对映选择性范围为 73-94% ee。