Emerging Activation Modes and Techniques in Visible-Light-Photocatalyzed Organic Synthesis

Abstract

AbstractVisible light photocatalysis has evolved into a promising mild and sustainable strategy to access radicals. This field unlocks formerly challenging or even previously inaccessible organic transformations. In this review, an overview of some lesser-known modes of photochemical activation of organic molecules and several emerging techniques within the versatile field of visible light photocatalysis are discussed. These are illustrated by selected photocatalytic reactions, with particular attention given to the reaction mechanism.1 Introduction2 Advanced Photoactivation Modes2.1 Photoinduced Hydrogen-Atom Transfer2.2 Proton-Coupled Electron Transfer2.3 Electron Donor-Acceptor Photoactivation of Organic Substrates2.4 Excited-State Transition Metal Catalysis3 Emerging Techniques3.1 Dual Catalysis3.2 Excited Radical Ion Photocatalysis3.3 Upconversion Strategies and Other Two-Photon Mechanisms3.4 Red and Near-Infrared Photocatalysis4 Conclusions and Outlook