Hybrid Pd/Fe3O4 nanowires: Fabrication, characterization, optical properties and application as magnetically reusable catalyst for the synthesis of N-monosubstituted ureas under ligand-free conditions

This paper reports the synthesis and use of Pd/Fe3O4 nanowires, as magnetically separable catalysts for ligand-free amidation coupling reactions of aryl halides with benzylurea under microwave irradiation. Then, the in Situ hydrogenolysis of the products was performed to afford the N-monosubstituted ureas in good to excellent yields. This method has the advantages of high yields, simple methodology and easy work up. The catalyst can be recovered by using a magnet and reused several times without significant loss of its catalytic activity. The catalyst was characterized using the powder XRD, SEM, EDS and UV-Vis spectroscopy. Experimental absorbance spectra compared with results from the Gans theory.