Indium trifluoride: A highly efficient catalyst for the synthesis of fluorine-containing 2,4,5-trisubstituted imidazoles under solvent-free conditions

A new green protocol has been developed for the synthesis of fluorine containing 2,4,5-trisubstituted imidazoles via one-pot, three-component condensation reaction of 4,4-difluorobenzil with aldehydes and ammonium acetate using reusable indium (III) fluoride (InF3) as Lewis acid catalyst under solvent-free conditions. This protocol provides a novel and improved method for obtaining fluorine containing 2,4,5-trisubstituted imidazoles in terms of good yields with little catalyst loading.