Asymmetric Michael Addition of Malonates to Enones Catalyzed by a Primary β-Amino Acid and Its Lithium Salt
作者:Masanori Yoshida、Mao Narita、Shoji Hara
DOI:10.1021/jo201429w
日期:2011.10.21
Highly enantioselective Michael addition of malonates to enones was achieved using a mixed catalyst consisting of a primary β-amino acid, O-TBDPS (S)-β-homoserine, and its lithium salt. Various cyclic and acyclic enones were converted into 1,5-ketoesters in high yields (up to 92%) with high enantioselectivity (up to 97% ee) under mild reaction conditions. Details of synthesis of the catalyst, optimization
使用由伯β-氨基酸,O - TBDPS(S)-β-高丝氨酸及其锂盐组成的混合催化剂,实现了丙二酸酯向烯酮的高度对映选择性迈克尔加成。在温和的反应条件下,各种环状和无环烯酮以高对映选择性(高达97%ee)高收率(高达92%)转化为1,5-酮酸酯。描述了催化剂的合成,迈克尔加成反应的反应条件的优化以及合理的反应机理的细节。