Photoredox Catalysis with Metal Complexes Made from Earth-Abundant Elements

Photoredox chemistry with metal complexes as sensitizers and catalysts frequently relies on precious elements such as ruthenium or iridium. Over the past 5 years, important progress towards the use of complexes made from earth-abundant elements in photoredox catalysis has been made. This review summarizes the advances made with photoactive Cr-III, Fe-II, Cu-I, Zn-II, Zr-IV, Mo-0, and U-VI com-plexes in the context of synthetic organic photoredox chemistry using visible light as an energy input. Mechanistic considerations are combined with discussions of reaction types and scopes. Perspectives for the future of the field are discussed against the background of recent significant developments of new photoactive metal complexes made from earth-abundant elements.