Enantioselective [3+2] annulation of isatin-derived MBH-carbonates and 3-nitroindoles enabled by a bifunctional DMAP-thiourea

A highly enantioselective [3+2] annulation of isatin-derived Morita–Baylis–Hillman (MBH) carbonates and 3-nitroindoles was enabled by a chiral DMAP-thiourea bifunctional catalyst, affording the corresponding polycyclic spirooxindoles bearing three consecutive stereocenters with good to excellent yields and enantioselectivities. Transformations of the annulation product were subsequently elaborated and the preliminary biological assays demonstrated that these artificial spirooxindoles potentially inhibited pancreatic lipase in a dose-dependent manner.