A novel approach towards synthesis of benzothiazoles and benzimidazoles: Eosin Y-catalyzed photo-triggered C-S and C-N bond formation

A novel metal-free and environment-friendly approach for synthesizing biologically important moieties, benzothiazoles and benzimidazoles, under visible light irradiation using photocatalyst Eosin Y, ethanol:water as a green solvent and atmospheric air as an oxidant has been developed. Using an organic dye, Eosin Y, provided a mild and economical catalytic system to synthesize a series of benzothiazoles and benzimidazoles in good to excellent yields. Besides, the photocatalytic system does not require an additional oxidant, which is good for the environment. This method has several advantages, including the absence of metals, low cost, environmental friendliness, green solvent, non-toxicity, ease of handling, and renewable energy sources such as visible light.