Microwave-Assisted Nickel-Catalyzed One-Pot Synthesis of 2,4,5-Trisubstituted Imidazoles

A novel, highly efficient, and one-pot microwave-assisted synthesis of 2,4,5-trisubstituted imidazoles using a newly developed Schiff's base complex nickel catalyst (Ni-C) is described. The approach involves the reaction of various aldehydes with benzil and ammonium acetate in the presence of the Ni-C catalyst to furnish cyclized products in excellent yields. The Ni-C catalyst exhibited remarkable catalytic activity with respect to the reaction time in the microwave reactor. The catalyst could be easily recovered by simple filtration and reused.