Catalytic Asymmetric Synthesis of α-Alkylidene-β-hydroxy Esters via Dynamic Kinetic Asymmetric Transformation Involving Ba-Catalyzed Direct Aldol Reaction

摘要

The direct catalytic asymmetric aldol reaction is a powerful and atom-economical method for synthesizing chiral β-hydroxycarbonyl compounds. To date, many metal and organocatalysts for reactions of ketone and aldehyde donors have been developed. These catalysts kinetically control aldol reactions via a simple proton-transfer process, avoiding undesirable retro-aldol reactions that would cause racemiza-tion of the products. In contrast, direct catalytic asymmetric aldol reactions with ester donors are limited to reactions with α-isocyanoacetate,~(3a) α-cyanoacetate,~(3b)α-diazoacetate, and glycinate Schiff base donors.