Synthesis of Phenothiazines via Ligand‐Free CuI‐Catalyzed Cascade C—S and C—N Coupling of Aryl ortho‐Dihalides and ortho‐Aminobenzenethiols.

A ligand-free CuI-catalyzed cascade C–S and C–N cross coupling of (hetero)aryl ortho-dihalides and ortho-aminobenzenethiols has been developed, and various phenothiazines were synthesized with excellent regioselectivity. A possible mechanism is proposed for the cascade coupling.