Diverse Visible‐Light‐Promoted Functionalizations of Benzotriazoles Inspired by Mechanism‐Based Luminescence Screening

Abstract Three new visible‐light‐promoted functionalizations of benzotriazole substrates were discovered using a mechanism‐based screening method. ortho ‐Thiolated, borylated, and alkylated N ‐arylbenzamide products were obtained under mild reaction conditions in a new denitrogenative synthetic approach to functionalized aniline derivatives. The functional group tolerance of the borylation reaction was further analyzed in the first application of an additive‐based robustness screen in a photocatalytic transformation. All the functionalizations proceed via photocatalytically initiated chain mechanisms as indicated by determination of the reaction quantum yields and Stern–Volmer analyses.