Synthesis of mesoporous Ca-MCM catalysts and their use in suitable multicomponent synthesis of polyfunctionalized pyrans
作者:Eliana Nope、José J. Martínez、Hugo A. Rojas、Ángel G. Sathicq、Gustavo P. Romanelli
DOI:10.1007/s11164-016-2749-7
日期:2017.4
Mesoporous Ca-MCM catalysts were prepared using a mixture of CaCO3, TEOS, cetyl trimethyl ammonium bromide (CTAB), triethanolamine (TEA), ethanol and H2O. Three catalysts with different CaCO3 contents, M-Ca 1 %, M-Ca 5 % and M-Ca 10 %, respectively, were prepared and characterized by N2 physisorption, XRD, FT-IR, XPS, TPD-CO2 and Pyridine-FTIR. A green and simple protocol was developed for the synthesis of 6-amino-4H-pyran scaffolds through a multicomponent coupling reaction of an aldehyde, malononitrile, and 1,3-dicarbonyl compound in different reaction solvents. This procedure was performed at room temperature (20 °C), obtaining good and excellent yields of 4H-pyran derivatives. The mesoporous materials are insoluble in polar media, which allows easy removal of the reaction products without affecting their catalytic activity. The leaching test showed an excellent stability, and Ca-MCM catalysts can be used three times without appreciable loss of their catalytic activity.
使用 CaCO3、TEOS、十六烷基三甲基溴化铵 (CTAB)、三乙醇胺 (TEA)、乙醇和水的混合物制备了介孔 Ca-MCM 催化剂。制备了三种不同 CaCO3 含量的催化剂(M-Ca 1 %、M-Ca 5 % 和 M-Ca 10 %),并通过 N2 物理吸附、XRD、傅立叶变换红外光谱、XPS、TPD-CO2 和吡啶-傅立叶变换红外光谱对其进行了表征。通过醛、丙二腈和 1,3-二羰基化合物在不同反应溶剂中的多组分偶联反应,开发出了一种合成 6-氨基-4H-吡喃支架的绿色简便方案。该反应在室温(20°C)下进行,获得了良好的 4H-吡喃衍生物。介孔材料不溶于极性介质,因此可以在不影响其催化活性的情况下轻松去除反应产物。浸出测试表明,Ca-MCM 催化剂具有极佳的稳定性,可以使用三次而不会明显丧失催化活性。