Highly enantioselective phase transfer catalyzed alkylation of a 3-oxygenated propionic ester equivalent: applications and mechanism

Phase transfer has proven to be a remarkably enantioselective alkylation catalyst in the alkylation of a 3-oxygenated propionic ester equivalent. It is applicable to other enolates, with the enantioselectivity varying predictably with the electronic effect of remote substituents on the enolate. An analysis of the alkylation process emphasizes the importance of charge density and entropy in determining the degree of enantioselectivity. Results offer fresh insights into catalytic enantioselective phase transfer reactions and a novel approach for the synthesis of various building blocks.