Direct coupling of inert C-H bonds in NHC organocatalysis

Direct coupling of inert C-H bonds by N-heterocyclic carbenes (NHCs) represents a fascinating area of research in organocatalysis. Recently, several notable studies have disclosed the potential of NHCs to directly functionalize latent C-H bonds of diverse simple molecules (e.g., ethers, amines, and arenes). These methodologies offer straightforward and efficient routes for C-C bond-forming transformations by diminishing the need for prefunctionalization manipulations of inert C-H bonds, allowing for the synthesis of a broad range of high value-added functional ketone molecules. Consequently, this highlight aims to present the latest advancements in NHC organocatalysis, specifically focusing on direct coupling functionalization of inert C-H bonds involving the electron or proton transfer process (ET/PT pathways) and hydrogen atom transfer pathway (HAT pathway).