Enantioselective synthesis of optically active cis-β-thio-α-amino acid derivatives through an organocatalytic cascade thio-Michael/ring opening process

Non-naturally enantioenriched cis-beta-thio-alpha-amino acid derivatives were synthesized through one pot, cascade thio-Michael/ring opening reaction of aromatic thiols with (Z)-olefinic azlactones in good yields with high levels of diastereoselectivities and enantioselectivities, which was catalyzed by a chiral bifunctional thiourea-tertiary amine catalyst.