Enantioenriched β-amino alcohols were prepared via an asymmetric addition of diethylzinc, catalyzed by the BozPHOS· Cu (I) complex, on in situ formed N-phosphinoylimines. The nature of the hydroxyl protecting groups was found to affect the enantioselectivities. Subsequent deprotection and oxidation of N-phosphinoyl β-amino alcohols afforded optically active α-amino acids (97% ee).