Copper and Iron Make the Difference: Developing Sustainable Photoredox Catalyzed Transformations

Abstract

Synthetic organic chemistry undertakes significant efforts to develop new catalytic transformations that utilize greener reagents and avoid stoichiometric additives. In this regard, visible-light photoredox catalysis offers a unique activation mode of molecules, which serves as an alternative to many thermal transition-metals catalyzed reactions. Most photoredox-catalyzed processes capitalize on heavy metals, namely, Ru(II) or Ir(III)-complexes, which can serve as single electron oxidants or reductants in their photoexcited states. Copper-and iron-based photo¬catalysts are rapidly emerging, offering economic and ecologic advantages but, in addition, can interact with substrates beyond electron transfer via inner sphere mechanisms, which have been successfully utilized to achieve challenging transformations. Emphasizing the principles of photoredox catalysis, selected synthetic applications from our laboratory will be discussed, highlighting the opportunities copper- and iron-photocatalysts offer in this area.