Access to Phenothiazine Derivatives via Iodide-Mediated Oxida-tive Three-Component Annulation Reaction.

Herein, a new iodide-mediated three-component annulation reaction of secondary anilines, cyclohexanones and elemental sulfur is demonstrated, which allows access to various phenothiazines with the merits of formation of multiple chemical bonds in one single operation, high step and atom efficiency, readily available feedstocks and catalyst system, good substrate and functional group compability. The developed chemistry capable of constructing novel phenothiazines with structural diversity offers a significant basis for further applications.