Visible light photoredox catalyzed controlled oxidative desulfurization of thioureas using CBr4: A new route for the synthesis of thioamidoguanidine

An efficient, photo-catalytic synthesis of thioamidoguanidine was developed through oxidative sulfurization of thioureas. The protocol involves the use of Ru(bpy) 3 Cl 2 (bpy = 2,2’-bipyridine)as a photo-catalyst, carbon tetrabromide (CBr 4 ) as the oxidizing reagent, and visible light as the source of energy at room temperature. Present reaction offers a practical, base-free, economically cheap reagent, an environmentally benign and safer approach for a variety of anti-Hugelchoff products.