Construction and Functionalization of Heteroarenes by Use of Photoredox Catalysis

The functionalization and the construction of heteroarenes with the aid of visible‐light photoredox catalysis have been investigated by a number of research groups. In this review, two different approaches are reported. In the first part, substitution of different heteroaryl derivatives is presented according to four classes of reactions: alkylation, perfluoroalkylation, C–X bond formation, and arylation. In the second part, construction of heteroaromatic cycles is reported according to the size and the structure of the ring. All of the processes deal with pure photoredox catalysis, and recent developments in dual catalysis are omitted.