The Use of NHC Carbenes in Enantiopure Compounds Synthesis

Abstract

Transformations mediated or catalyzed by N-Heterocyclic Carbenes (NHC) have become important tools for the synthesis of complex compounds with varied functionalities. The use of NHCs in synthesis of enantiopure compounds have increased significantly during the past 10 years, especially after Stetter's 1975 study on the entire synthesis of cis-jasmon and dihydrojasmon utilizing carbene catalysis. Unquestionably, the recent advancements in NHC-catalyzed reactions, including new benzoin, Stetter, homoenolate, aroylation procedures, [3+2], [3+3], [4+2], [5+5] annulation reactions, Michael type additions account for this renaissance. These transformations, which make use of both conventional and umpolung forms of bond disconnections are the foundational steps in a number of novel syntheses protocols to make valuable scaffolds and some of these paved excellent paths in total synthesis. The enthusiasm and newly discovered synthetic value of carbene catalysis in synthesis of enantiopure scaffolds are highlighted in this chapter with recent literature covered close to a decade.