功能化离子液体支载脯氨酸催化的Knoevenagel缩合反应

Knoevenagel Condensation Catalyzed by Functionalized Ionic Liquid-supported Proline

将L-脯氨酸支载在功能化离子液体四氟硼酸1-（2-羟乙基）-3-甲基咪唑鎓盐上合成了一种功能化的离子液体支载脯氨酸催化剂（[Promim]CF3COO）,该催化剂可在温和条件下顺利地催化丙二腈和一系列芳香醛进行的Knoevenagel缩合反应,目标产物的产率达到80%~98%,选择性为99%以上.反应操作和后处理简单方便,离子液体支载脯氨酸催化剂通过简单的处理即可实现循环利用,以对-氯苯甲醛和丙二腈为反应底物的模板反应,该催化剂可以较稳定地循环使用,到第4次时产率为86%.

A functionalized ionic liquid-supported proline,1-methyl-3-{2-[（2S）-pyrrolidine-2-carbonyloxy]-ethyl}-1H-imidazol-3-ium trifluoroacetate（[Promim]CF3COO）,was synthesized and used to catalyze Knoevenagel condensation of aromatic aldehydes with malononitrile.The desired alkenes were obtained in good purity and 80% to 98% yields under relatively mild conditions without solvent.The procedure is simple and the ionic liquid-supported proline could be recycled efficiently.With the condensation of p-chlorobenzaldehyde and malononitrile as an example,the ionic liquid-supported proline was recycled four times with a slight decrease in catalytic and a yield of 86% was gained.