N-Heterocyclic Carbene Catalyzed Activation of Esters: A New Option for Asymmetric Domino Reactions

摘要

In recent years we have witnessed tremendous progress in the field of asymmetric organocatalytic domino reactions due to the inherent advantages associated with these cascade sequences as well as many applications in the asymmetric synthesis of precious multifunctionalized chiral molecules including natural products and drugs. Over the last five years, N-heterocyclic carbenes (NHCs) have caught up in importance with other organocatalyts in the development of new asymmetric domino transformations. In particular, the organocatalytic functionalization of important carbonyl compounds such as aldehydes and ketones as well as their α,β-unsaturated variants plays a central role in the design of new asymmetric domino reactions through Lewis base catalysis employing amines or NHCs.