Novel Urea-Functionalized Magnetic Nanoparticles as a Heterogeneous Hydrogen Bonding Catalyst for the Synthesis of New 2-Hydroxy Pyridines

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.

Graphical Abstract

Keywords:

• Hydrogen bonding catalyst
• pyridine
• sulfonate
• sulfonamide
• vinylogous anomeric-based oxidation

Acknowledgments

We thank the Bu-Ali Sina University and the Iran National Science Foundation [(INSF), Grant Number: 98001912) for financial support to our research group.

Additional information

Funding

We thank the Bu-Ali Sina University and the Iran National Science Foundation [(INSF), Grant Number: 98001912) for financial support to our research group.