Enantioselective reactions of tert-butyl glycinate–benzophenone Schiff base catalyzed by chiral phase-transfer catalyst in aqueous media without any organic solvent

Chiral phase-transfer catalyzed enantioselective alkylations of tert-butyl glycinate–benzophenone Schiff base were investigated in aqueous media without any organic solvent. Reactions in aqueous media smoothly proceeded to give the desired product in higher yield than under standard liquid–liquid biphasic conditions. In aqueous media the formation of benzophenone, which was caused by in situ hydrolysis of Schiff base, was depressed.