Recent Advances on Computational Investigations of N-Heterocyclic Carbene Catalyzed Cycloaddition/Annulation Reactions: Mechanism and Origin of Selectivities

The developments of theoretical studies on NHC-catalyzed [n+2] (n=2, 3, 4) and other cycloaddition/annulation reactions have been summarized in this review. The detailed mechanisms, role of NHC, and origin of chemo- and stereoselectivity of these kinds of reactions were illustrated to provide valuable insights for rational design of new NHC-catalyzed cycloaddition/annulation reactions with high selectivities. Moreover, computational and theoretical methods commonly used were also mentioned to open the door for deep exploration of the general principle for NHC-catalyzed reactions within theoretical chemistry.