Facile Synthesis of 1,2,4-trisubstituted Imidazoles via Aerobic Copper Catalyzed Ligand-free [3+2] Cycloaddition

A simple and facile approach to highly functionalized imidazole derivatives in moderate to good yields has been developed. This method involves copper catalyzed aerobic [3+2] cycloaddition of amidines with nitroolefins in absence of ligand. Based on observation of the intermediates, possible reaction mechanism different from the same reported approach was proposed.