Visible-Light-Induced Oxidative Generation of o-Quinone Methides for Inverse-Electron-Demand [4+2] Cycloaddition Reactions

Abstract Organophotoredox-catalyzed oxidative generation of o-quinone methides (o-QMs) for inverse-electron-demand [4+2] cycloaddition reactions has been developed. One-electron oxidation of 2-(sulfanylmethyl)phenols by thioxanthylium photoredox catalyst generated o-QMs, which reacted with various styrenes to produce chromanes with high regioselectivity. This reaction offers a valuable approach for in situ generating o-QMs via one-electron oxidation process under irradiation with mild green light.