Stereoselective Reactions Catalyzed by N-Heterocyclic Carbenes

N-Heterocyclic carbenes (NHCs) as one of the most powerful reagents, ligands and organocatalysts for various reactions have been widely used in modern synthetic applications. Especially, the chiral NHCs have attracted intense attention in stereoselective reactions from synthetic chemists based on their highly efficiency and unique catalytic properties with excellent diastereoselectivity and enantioselectivity. A great deal of exciting achievements in the synthesis and applications of chiral NHC catalysts have been attained over the past decades. This review will mainly summarize recent advances in the chiral NHC-catalysed stereoselective reactions according to the use of NHCs including the generation of equivalents acyl anions, homoenolates, azolium enolates/acyl azoliums and oxidative NHC catalysis.