Catalytic behavior of surfactant-containing-MCM-41 mesoporous materials for cycloaddition of 4-nitrophenyl azide

Abstract

Si-MCM-41, Ga-MCM-41 and Al-MCM-41 mesoporous catalysts (with Si/Al=80 and Si/Ga=80) were prepared by direct synthesis under hydrothermal crystallization method using sodium aluminate or gallium sulfate and tetraethyl orthosilicate (TEOS) as aluminum or gallium and silica sources, respectively. The structural features of the materials were determined by various physico-chemical techniques such as X-ray diffraction (XRD), nitrogen sorption at 77K, Fourier transform infrared spectroscopy (FTIR), scanning and transmission electronic microscopy (SEM, TEM) and thermogravimetric analysis ATG. The catalytic activity of the calcined and as-synthesized catalyst was evaluated through the cycloaddition reaction of 4-nitrophenyl azide with activated alkenes at room temperature under liquid-phase conditions. High yields of 1,2,3-triazole were obtained. For comparison purpose, mixtures of homogeneous and heterogeneous catalyst Et3N/M-MCM-41 (M=Al or Ga) are also tested. The catalyst was used in five consecutive experiments without important loss of activity, confirming its stability. Finally, a new method for preparing triazoles in short reaction times was developed.