Highly efficient polymer supported phase-transfer catalysts containing hydrogen bond inducing functional groups

Abstract Merrifield resin supported cinchona ammonium salts bearing 2′-fluorobenzene, 2′-cyanobenzene and 2′- N -oxypyridine groups were prepared and applied to the phase-transfer catalytic alkylation of N -(diphenylmethylene)glycine tert -butyl ester for the enantioselective synthesis of α-amino acids (76–96% ee).