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

Organophotoredox-catalyzed oxidative generation of o-qui-none methides (o-QMs) for inverse-electron-demand [4+2] cycloaddition reactions has been developed. One-electron oxidation of 2-(sulfa-nylmethyl)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 situgenerating o-QMs via one-electron oxidation process under irradiation with mild green light.

Automated summary

An organophotoredox-catalyzed oxidative synthesis of o-QMs for inverse-electron-demand [4+2] cycloaddition reactions has been developed. The reaction involves one-electron oxidation of 2-(sulfanyl-methyl)phenols by a thioxanthylium photoredox catalyst, generating o-QMs that react with various styrenes to produce chromanes with high regioselectivity.