Aerobic Visible-Light Photoredox Radical C–H Functionalization: Catalytic Synthesis of 2-Substituted Benzothiazoles

Abstract
An aerobic visible-light driven photoredox catalytic formation of 2-substituted benzothiazoles through radical cyclization of thioanilides has been accomplished. The reaction features C–H functionalization and C–S bond formation with no direct metal involvement except the sensitizer. The reaction highlights the following: (1) visible-light is the reaction driving force; (2) molecular oxygen is the terminal oxidant, and (3) water is the only byproduct.