Dimeric cinchona ammonium salts with benzophenone linkers: Enantioselective phase transfer catalysts for the synthesis of α-Amino acids

Abstract

Chiral phase transfer catalysts of dimeric cinchona ammonium salts linked with a benzophenone bridge showed high enantioselectivity in the α-Alkylation of a glycinate ester under mild industry-Applicable conditions: 0.5 mol% PTC and near equivalents of alkyl halide. A dual function of the dimeric quinuclidiniums was proposed for the high efficiency.