Silica boron–sulfuric acidnanoparticles (SBSANs): preparation, characterization and their catalytic application in the Ritter reaction for the synthesis of amide derivatives

Abstract

Among a number of different heterogeneous and homogeneous catalysts, silica boron–sulfuric acid nanoparticles (SBSANs) with both protic and Lewis acidic sites were shown to be the most active and recyclable catalyst in the Ritter reaction. Various amide derivatives were synthesized from alcohols and nitrilesvia a one-step and easy process in the presence of a catalytic amount of SBSAN at room temperature in solvent free conditions with excellent isolated yields. The silica boron–acid nanoparticles (SBANs) were regularly synthesized during the modification of the silica support by boric acid [B(OH)₃] during the chemical vapor deposition (CVD) process and subsequently, this material was reacted with chlorosulfonic acid (ClSO₃H) to obtain the SBSAN catalyst. The new catalyst was characterized using some different microscopic and spectroscopic techniques such as patterned X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), FT-Raman spectrometry and FT-IR spectroscopy. Thermal behavior of the SBSAN catalyst was also investigated by a thermogravimetric (TG) analyzer.