Recent advances in photoredox catalytic transformations by using continuous-flow technology

Photoredox catalysis is regarded as an economically appealing method for highly efficient and sustainable chemical syntheses. Nevertheless, numerous recent studies have revealed several unresolved disadvantages; for example, based on the Bouguer-Lambert-Beer law, the short propagation distance of photons in traditional batch reactors hampers the scalability of photocatalytic reactions. The introduction of continuous-flow technology for photochemical synthesis has resolved several of these problems. The use of photochemistry in microreactors has resulted in various transfor-mations. Superior mixing ability, more effective heat transfer, and the easier magnification of continuous-flow chemical reactions are key to its success. Continuous-flow technology has allowed the optimization of several different types of conversion. Photoredox catalysts are effective under vari-ous reaction conditions because of their single-electron transfer properties. Common photocatalysts include transition metal complexes containing ruthenium, iridium, copper, iron, or manganese; organic photocatalysts; and heterogeneous photocatalysts. This review covers the types of photo-catalysts that have recently been used in continuous-flow photochemistry.& COPY; 2023, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.