Highly enantioselective alkylation of glycine methyl and ethyl ester derivatives under phase-transfer conditions: its synthetic advantage

Phase-transfer alkylation of the benzophenone Schiff base of glycine methyl or ethyl ester (2) was found to be catalyzed by 3,4,5-F3-C6H2-NAS-Br [(S,S)-1] with high efficiency and excellent enantioselectivity. This procedure allows facile derivatization of the resulting alkylation products to other synthetically useful chiral building blocks.