Construction of polycyclic spirooxindoles through3+2annulations of Morita–Baylis–Hillman carbonates and 3-nitro-7-azaindoles

摘要

A mild and efficient dearomatic [3+2] annulation reaction of 3-nitro-7-azaindoles and Morita Baylis Hillman carbonates from isatins was developed catalyzed by DMAP, affording the corresponding polycyclic spirooxindoles containing fused azaindoline architectures and vicinal quaternary centers in excellent yields(up to 96%) with high regio- and diastereoselectivity(dr > 19:1). Moderate enantioselectivity(79% ee) was obtained by employing a chiral DMAP-type Lewis base catalyst.