Synthesis of α,β -diamino acid derivatives by acid-catalyzed Aza-Michael addition of N -phthalyldehydroalanine with different amine

A series of α,β-diamino acid derivatives were synthesized from N-phthalyldehydroalanine with different amines by acetic acid catalytic Aza-Michael additions. This reaction achieves C–N bond formation with good functional group tolerance. Under optimized conditions, the desired products of most aromatic and secondary aliphatic amines were obtained in moderate to good yields under mild conditions. The electronic effect and steric effect play the important roles to the reactivity of amines.