Immobilized Iron Metal-Containing Ionic Liquid-Catalyzed Chemoselective Transfer Hydrogenation of Nitroarenes into Anilines

The chemoselective transfer hydrogenation of nitroarenes into anilines was investigated using immobilized iron metal containing ionic liquid (ImmFe-IL) as a versatile heterogeneous catalyst. The present protocol has high atom efficiency with excellent chemosectivity and regioselectivity. Selective reduction of the nitro group was observed in the presence of other reducing functional groups such as nitrile, ketone, acid, amide, ester, halogens, hydroxyl, olefin, and heterocycles. The developed protocol is also highly selective toward conversion of dinitroarenes into nitroanilines. The present catalytic system uses environmentally benign ethylene glycol as a solvent which is inexpensive, easily available, nontoxic, nonvolatile, nonflammable, thermally stable, and biodegradable. The catalyst was reused up to four consecutive cycles with high activity and selectivity. The fresh catalyst and recycle catalyst was well characterized by XPS analysis.