Visible-light-induced (hetero)aryl–heteroaryl bond-forming reactions

Heteroaryl-heteroaryl and aryl-heteroaryl bonds are found in many biologically active compounds, including drug molecules and useful materials. Consequently, several synthetic strategies have been developed for these challenging bond-forming reactions. Among all, visible-light-induced protocols are most useful owing to their unique features, such as no requirement for pre-functionalized substrates, mild reaction conditions, high regioselectivity, and high sustainability. In this review article, we report the development of various visible-light-induced procedures for the formation of heteroaryl-heteroaryl and aryl-heteroaryl bonds, involving both intermolecular and intramolecular reactions, which have led to the synthesis of bi(hetero)aryls over the last decade. We have also highlighted the synthetic procedures for easy access to several biologically active compounds, including drug molecules, using this protocol.