Umpolung strategy: advances in catalytic C-C bond formations

This mini-review examines the recent advances in umpolung strategy, devised originally by Corey and Seebach. Although numerous stoichiometric variants have been published to date, this article covers just the catalytic C-C bond forming reactions due to their major benefits such as atom economy, less pollution, and workable simplicity. In the context of umpolung, the studies are evaluated under 3 main titles: enzyme, N-heterocyclic carbene, and cyanide ion catalyzed reactions. In particular, enzyme and NHC catalyzed reactions mainly involve asymmetric applications.