Novel Urea-Functionalized Magnetic Nanoparticles as a Heterogeneous Hydrogen Bonding Catalyst for the Synthesis of New 2-Hydroxy Pyridines
Narges Zarei, Morteza Torabi, Meysam Yarie, Mohammad Ali Zolfigol
Abstract
A novel urea-functionalized silica-coated magnetic nanoparticle namely Fe3O4@SiO2@UBL was described as a reusable and recoverable heterogeneous hydrogen bonding catalyst. For characterization of the catalyst, varied techniques including Fourier-transform infrared (FT‐IR) spectroscopy, energy dispersive X‐ray (EDX) analysis, elemental mapping analysis, thermo gravimetric analysis/differential thermal analysis (TGA/DTG), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and vibrating sample magnetometer (VSM) were applied. Then, its catalytic performance was screened for the synthesis of new 2-hydroxy pyridine derivatives bearing sulfonate or sulfonamide moiety. Also, in a plausible mechanistic route, the stereoelectronic role of a cooperative vinylogous anomeric-based oxidation is suggested for the aromatization of targeted molecules.