N-heterocyclic carbene-catalyzed reactions of C–C unsaturated bonds
Abstract
The N-heterocyclic carbene-catalyzed reactions of C–X (X = O, S, N) unsaturated bonds are well established. However, C–C unsaturated bonds are challenging substrates for NHC-catalyzed reactions. In recent years, several reports have demonstrated that NHC-catalyzed reactions of C–C unsaturated bonds are feasible, including the umpolung of Michael acceptors, the Morita–Baylis–Hillman reaction, and the annulation reactions of vinyl sulfones, nitroalkenes, allenoates and alkynes.