Catalyst-controlled stereoselective carbon–heteroatom bond formations by N-heterocyclic carbene (NHC) organocatalysis

The development of synthetic strategies towards enantioselective access to carbon–heteroatom bonds by means of catalyst control continues to receive considerable interest in organic chemistry. Over the past decades, N-heterocyclic carbene (NHC) organocatalysis has witnessed extensive exploration for a rapid assembly of asymmetric carbon–heteroatom bonds in a wide range of novel chemical transformations. A diverse set of activation modes and NHC-derived intermediates, such as Breslow intermediates, acyl azoliums, etc ., that feature distinct nucleophilicity or electrophilicity have been demonstrated to exhibit substantial potential in the construction of carbon–heteroatom bonds. This review will summarize recent advances in stereoselective carbon–heteroatom bond forming reactions, including C–N, C–O, C–S, C–F, C–P, etc ., that were enabled by NHC organocatalysis with a focus on new activation modes and reactive intermediates, aiming to inspire unique insights into the preparation of chiral functional molecules by the use of NHC organocatalysis.