N-Heterocyclic Carbene-Catalyzed Redox Reactions of α-Functionalized Aldehydes

This review summarizes the recent advances on the redox reactions involving alpha-functionalized aldehydes catalyzed by N-heterocyclic carbenes. In the presence of N-heterocyclic carbene, alpha-functionalized aldehydes such as alpha-haloaldehydes, alpha-ring-fused aldehydes, alpha-aryloxyacetaldehydes and alpha-aroyloxyaldehydes undergo the redox reactions affording novel reaction types.