【摘要】 合成了碱性功能化离子液体氢氧化1-丁基-3-甲基咪唑([BMIM]OH),研究了将其作为催化剂催化芳香醛和丙二氰、氰基乙酸乙酯的Knoevenagel缩合反应。结果表明,在无溶剂条件下,采用摩尔分数为5%的该碱性功能化离子液体催化剂量,无需加入其它催化剂,能在较温和条件下催化Knoevenagel缩合反应,产率达81%～97%。在该反应体系中考察了一系列芳香醛和丙二氰、氰基乙酸乙酯的缩合反应,并推测了Knoeve-nagel缩合反应的机理,芳香醛与氰基乙酸乙酯缩合产物经1HNMR检测为E式烯烃。反应操作和后处理简单方便,离子液体通过简单的处理即实现回收利用。以苯甲醛和丙二氰为反应底物的模板反应,离子液体循环使用,其催化活性未明显降低,第3次使用时产率为86%。更多还原

【Abstract】 The basic functionalized ionic liquid, 1-butyl-3-methylimidazolium hydroxide([BMIM]OH), was prepared and used to catalyze the Knoevenagel condensation of aromatic aldehydes with malononitrile or ethyl cyanoacetate. The results show that the Knoevenagel condensation proceeds smoothly in the presence of 5% basic functionalized ionic liquid to afford the desired alkenes in good purity and 81%～97% yields under relatively mild conditions without solvent or any added catalyst. In this catalyst system, the Knoevenagel condensations of a series of aromatic aldehydes with malononitrile or ethyl cyanoacetate were programmed and a mechanism was postulated as well. When aromatic aldehydes reacted with ethyl cyanoacetate, the corresponding alkenes proved to be E-isomers by 1H NMR. The procedure is simple and the ionic liquid could be recycled efficiently. With the condensation of benzaldehyde and malononitrile as an example, the ionic liquid was recycled three times with a slight decrease in catalytic activity and a yield of 86% was gained.更多还原