Catalytic asymmetric Michael and Nef-type sequential reaction of nitroolefin with azlactone to construct oxazole-fused succinimide

Abstract

A series of oxazole-fused succinimides bearing vicinal quaternary carbon centers were synthesized. This process takes place between nitroolefins and azlactones in the presence of a bifunctional chiral guanidine-sulfonamide organocatalyst, followed by a Nef-type transformation under the treatment of DMAP/Ac₂O. Several control experiments were conducted to propose the mechanism.