Accelerating photoredox catalysis in continuous microflow

Owing to the generally mild reaction conditions, photoredox catalysis has become very popular in recent years and has affected a renewed interest in the use of solar energy to establish chemical transformations. In the last decade, continuous microfl ow reactors have received an increasing amount of attention to facilitate photochemical reactions. In such reactors, improved irradiation of the reaction medium and the ability to immobilize the photocatalyst have impacted the photoredox catalyzed process signifi cantly and have allowed to reduce both the catalyst amount and the reaction times. Hereby, we highlight recent efforts in the application of continuous microfl ow reactors in photoredox catalysis. The use of transition metal catalyzed photoredox processes as well as metal free photoredox processes in continuous microfl ow are discussed and compared with their batch counterparts.