Cinchona-Based Primary Amine-Catalyzed Asymmetric Cascade Aza-Michael–Aldol Reactions of Enones with 2-(1<i>H</i>-Pyrrol-2-yl)-2-oxoacetates: Synthesis of Chiral Pyrrolizines with Multistereocenters
作者:Hyo-Jun Lee、Chang-Woo Cho
DOI:10.1021/jo4001614
日期:2013.4.5
Cinchona-based primary amine-catalyzed cascade aza-Michael–aldol reactions of α,β-unsaturated ketones with 2-(1H-pyrrol-2-yl)-2-oxoacetates provided highly functionalized chiral pyrrolizines bearing multistereocenters including a chiral quaternary carbon center in good yields (up to 92%) with excellent levels of stereocontrol (90–95% ee, >20:1 dr in all cases). The ketone group in the cascade product was asymmetrically
α,β-不饱和酮与2-(1 H-吡咯-2-基)-2-氧代乙酸酯的金鸡纳胺伯胺催化的级联氮杂-迈克尔-醛醇缩合反应,提供了高度官能化的手性吡咯嗪,带有多个手性中心,包括手性季碳原子中心具有良好的立体控制水平(高达90–95%ee,在所有情况下> 20:1 dr),且收率高(高达92%)。级联产物中的酮基团不对称地还原为手性仲羟基,收率很高。