Aerobic cross-dehydrogenative couplings of N-heteroarenes with toluene derivatives at room temperature

Abstract

A set of mild aerobic cross-dehydrogenative couplings of N-heteroarenes with the benzylic C(sp³)–H bond has been achieved by using visible-light-induced photocatalysis. This approach was found to provide a sustainable alternative to Minisci benzylation reactions using readily accessible toluene derivatives as benzylating agents. The unique combination of photocatalysis, bromo radical mediation, and aerobic oxidation proved to be the key for the success of the transformation. Mechanistic studies revealed the feasibility of both oxidative and reductive quenching of the excited photocatalyst in the initial step.