Employing homoenolates generated by NHC catalysis in carbon–carbon bond-forming reactions: state of the art

Homoenolate is a reactive intermediate that possesses an anionic or nucleophilic carbon β to a carbonyl group or its synthetic equivalent. The recent discovery that homoenolates can be generated from α,β-unsaturated aldehydes via N-Heterocyclic Carbene (NHC) catalysis has led to the development of a number of new reactions. A majority of such reactions include the use of carbon-based electrophiles, such as aldehydes, imines, enones, dienones etc. resulting in the formation of a variety of annulated as well as acyclic products. The easy availability of chiral NHCs has allowed the development of very efficient enantioselective variants of these reactions also. The tolerance showed by NHCs towards magnesium and…