氨基化磁性纳米粒子催化的克脑文格尔反应

摘要

为了克服克脑文格尔缩合反应中催化剂难于与产物分离、不能循环使用的问题,以聚乙烯亚胺包覆Fe3O4制得氨基化磁性纳米粒子催化剂;采用X射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)、热重分析(TG)等手段对其结构进行了表征.将氨基化磁性纳米粒子催化剂用于多种醛与丙二腈或氰乙酸乙酯的克脑文格尔缩合反应,室温下反应进行顺利;当底物为芳香醛时,所有反应的转化率和缩合产物的选择性都高于99％,产物的分离收率大于或接近90％.该催化剂易于与产物分离并可循环使用,循环使用6次,催化活性几乎没有降低,证明该氨基化磁性纳米粒子是一种催化性能优良的克脑文格尔缩合反应催化剂.%In order to overcome the problems of difficult separation and non-recyclability of the catalysts in Knoevenagel condensation,amino-functionalized magnetic nanoparticles were obtained by coating of Fe3 O4 with polyethyleneimine,which were characterized by XRD,FT-IR and TG analysis.The amino-functionalized magnetic nanoparticles were applied to the Knoevenagel condensation reaction between various aldehydes and malononitrile or ethyl cyanoacetate,and the reaction proceeded smoothly at room temperature.This catalyst was easily recovered and could be recycled for 6 times without any deactivation of its activity,which confirmed that the amino-functionalized magnetic nanoparticles were excellent catalysts for the Knoevenagel condensation reaction.