Copper-catalysed cascade synthesis of imidazolidine-benzothiazole and imid­azolidine-tetrazole hybrid heterocycles from bis-thioureas by a desulfurisation strategy

Abstract

The in situ generated bis‐thioureas obtained by treating aryl/alkyl isothiocyanates with aliphatic 1,2‐diamines, upon treatment with Cu^I or Cu^II salts, depending on their quantity and the reaction conditions, furnished either imidazolidinecarbothioamide (ImCAT) or imidazolidine–benzothiazole (ImBT) hybrid molecules. The same reactions in the presence of sodium azide yielded imidazolidine–tetrazoles (ImTets). The products were obtained in good yields at room temperature with all these processes taking place in a single pot. This is a perfect illustration of Cu salts serving as both desulfurising as well as C–H activating agents at ambient temperature.