A New Trimeric Cinchona Alkaloid as a Chiral Phase-Transfer Catalyst for the Synthesis of Asymmetric α-Amino Acids

Abstract

A new trimeric cinchona alkaloid, the quaternary ammonium salt, a,a',a-tris[O(9)-allylcinchonidinium-(4-methylphenoxymethyl)]benzene trichloride, has been synthesized and used as an efficient phase-transfer catalyst in asymmetric alkylation of N-(diphenylmethylene)glycine tert-butyl ester with very good yield (up to 97%) and high enantioselectivity (up to 98%).