Madkour Metwally, Khalil Khaled D, Al-Sagheer Fakhreia A
Chemistry Department, Faculty of Science, University of Kuwait, P.O. Box 5969, Safat 13060, Kuwait.
Chemistry Department, Faculty of Science, Cairo University, P.O. 12613, Gisa 12573, Egypt.
Polymers (Basel). 2021 Oct 17;13(20):3583. doi: 10.3390/polym13203583.
Chitosan/magnesia hybrid films (CS-Mg) have been prepared via sol-gel process and employed as heterogeneous catalysts. An in situ generation of a magnesia network in the chitosan matrix was performed through hydrolysis/condensation reactions of magnesium ethoxide. The synthesized hybrid films were characterized using various analytical techniques, such as X-ray photo-electron spectroscopy (XPS), field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). The hybrid films display excellent catalytic activities in Michael and Knoevenagel reactions via one pot or solvent-free approaches under microwave irradiation conditions. Chitosan/magnesia hybrid films, catalysed pyrimidine, benzochromene, coumarin and arylidene-malononitriles derivatives formation reactions occurred with highly efficient yields of 97%, 92%, 86% and 95% respectively. Due to the fact that the films are durable and insoluble in common organic solvents, they were easily separated and can be recycled up to five times without a considerable loss of their catalytic activity.
壳聚糖/氧化镁杂化膜（CS-Mg）通过溶胶-凝胶法制备，并用作多相催化剂。通过乙醇镁的水解/缩合反应在壳聚糖基质中原位生成氧化镁网络。使用各种分析技术对合成的杂化膜进行表征，如X射线光电子能谱（XPS）、场发射扫描电子显微镜（FESEM）和原子力显微镜（AFM）。在微波辐射条件下，杂化膜通过一锅法或无溶剂方法在迈克尔反应和克诺文纳格尔反应中表现出优异的催化活性。壳聚糖/氧化镁杂化膜催化嘧啶、苯并色烯、香豆素和亚苄基丙二腈衍生物的形成反应，产率分别高达97%、92%、86%和95%。由于该膜耐用且不溶于常见有机溶剂，它们易于分离，并且可以循环使用多达五次而其催化活性没有明显损失。
