Meng Dan, Qiao Yongsheng, Wang Xin, Wen Wei, Zhao Sanhu
School Chemistry and Material Science, Shanxi Normal University Linfen 041001 Shanxi China
Department of Chemistry, Xinzhou Teachers University Xinzhou 034000 Shanxi China.
RSC Adv. 2018 Aug 28;8(53):30180-30185. doi: 10.1039/c8ra06506c. eCollection 2018 Aug 24.
-(2-Hydroxy-ethyl)-pyridinium chloride ([HyEtPy]Cl) was synthesized and explored as a novel promoter for 1,4-diazabicyclo [2.2.2] octane (DABCO)-catalyzed Knoevenagel condensation reactions, which showed better catalytic activity compared to other ionic liquid (IL) that had no hydroxyl group attached to the IL scaffold. The effect of hydrogen bond formation between the hydroxyl group of [HyEtPy]Cl and the carbonyl group of aldehyde played an important role in the Knoevenagel condensation reaction. In the [HyEtPy]Cl-HO-DABCO composite system, Knoevenagel condensation reactions proceeded smoothly and cleanly, and the corresponding Knoevenagel condensation products were obtained in good to excellent yields in all cases examined. This protocol provides a versatile solvent-catalyst system, which has notable advantages such as being eco-friendly, ease of work-up and convenient reuse of the ionic liquid.
合成了氯化（2-羟乙基）吡啶鎓（[HyEtPy]Cl），并将其作为一种新型促进剂用于1,4-二氮杂双环[2.2.2]辛烷（DABCO）催化的Knoevenagel缩合反应，与其他在离子液体骨架上未连接羟基的离子液体相比，它表现出更好的催化活性。[HyEtPy]Cl的羟基与醛的羰基之间形成氢键的作用在Knoevenagel缩合反应中起着重要作用。在[HyEtPy]Cl-HO-DABCO复合体系中，Knoevenagel缩合反应顺利且干净地进行，在所有考察的情况下，相应的Knoevenagel缩合产物均以良好至优异的产率得到。该方法提供了一种通用的溶剂-催化剂体系，具有环保、后处理简便以及离子液体可方便重复使用等显著优点。
