Helical carbenium ion-based organic photoredox catalyst: A versatile and sustainable option in red-light-induced reactions

The development of a sustainable catalytic system for red-light-induced photocatalysis is presented. The catalytic system consists of a helical carbenium ion-based organic photoredox catalyst (PC) that is capable of using low-energy red light (λ max = 640 nm) for both photooxidations and photoreductions. Its successful applications in the aerobic oxidative hydroxylation of arylboronic acids and in the oxidation of benzylic C(sp 3)-H bonds (reductive quenching), as well as in dual transition-metal/organocatalyzed C-H arylations and intermolecular atom-transfer radical additions (oxidative quenching) provide further support for its role as a versatile and efficient organic PC. 1 Introduction 2 Red-Light-Induced Photocatalysis 3 Properties of N, N ′-Dipropyl-1,13-dimethoxyquinacridinium Tetrafluoroborate 4 Two Proposed Representative Catalytic Cycles of [ n Pr-DMQA + ][BF 4- ] 5 Applications of [ n Pr-DMQA + ][BF 4- ] in Red-Light-Induced Photocatalysis 6 Conclusion.