The Michael addition to nitroolefins of manganese enolates derived from an array of ketones is reported. The desired 1,4-adducts are obtained in high yield and excellent diastereo- and regioselectivity, the sole kinetic adduct being obtained in the case of nonsymmetrical ketones. The effect of a thiourea-type organocatalyst on the addition of several representative nitroolefins to the kinetic manganese enolate derived from isopropyl ethyl ketone is also reported.
据报道,迈克尔加成反应在硝基烯烃和从一系列酮衍生的
锰烯醇化物之间进行。期望的1,4-加合物以高产率和优异的立体选择性及区域选择性获得,在不对其称的酮中,仅得到唯一的动力学加合物。同时,也报道了
硫脲类有机催化剂对从异丙基乙基酮衍生的动力学
锰烯醇化物与几种代表性硝基烯烃加成反应的影响。