Recent Trends in the Deformylative C-H Arylation/alkylation of (Hetero)arenes with Aldehydes.

Direct C-H functionalization of unactivated (hetero)arenes with organohalides or sulfonates has proven to be an effective strategy for the formation of new C(aryl)-C(aryl/alkyl) bonds. However, organo(pseudo)halides are mainly highly toxic, which is unfavourable for large-scale and sustainable use. As an alternative to this method, deformylative C-H functionalization of (hetero)arenes with aldehydes has been suggested to be effective because it could further enrich the synthetic methodology due to low-cost, nontoxicity, and easy accessibility of aldehydes. In this review, we focus on the recent advances in this promising and hot research topic which may inspire further research in this domain.