Iron-Catalyzed Photoredox Intermolecular Dearomatization of Benzothiazoles with Alkanes

Benzothiazolines, with their versatile nature, serve as fundamental building blocks for the synthesis of significant biological compounds. However, methods for the preparation of benzothiazolines from readily available starting materials are limited. An efficient synthesis of benzothiazoline via photoredox-catalyzed dearomatization of benzothiazole derivatives has been achieved at room temperature. This catalysis proceeds via a ligand to metal charge transfer process, and FeCl3 plays a dual role as an indirect HAT reagent and reducing agent. This methodology can be conveniently scaled up, and most of the alkylated products can be purified without chromatography. In addition, this process exhibited the advantages of low cost, high reaction efficiency, and mild conditions.