Applied Chemistry Research Group, ACECR-Tehran Organization, P.O. Box 13145-186, Tehran, Islamic Republic of Iran.
Applied Chemistry Research Group, ACECR-Tehran Organization, P.O. Box 13145-186, Tehran, Islamic Republic of Iran.
Int J Biol Macromol. 2018 Jul 1;113:711-718. doi: 10.1016/j.ijbiomac.2018.03.020. Epub 2018 Mar 5.
Owe to unique advantages of heterogeneous catalytic reactions, there is increasing interest to use this type of chemical transformations in organic synthesis. Among various heterogeneous catalytic systems, magnetic supported ionic liquids are emerging ones in the chemical synthesis. As a result, this research focuses on developing an efficient magnetically recyclable catalytic system for Michael-type addition reaction based on quaternized γ-FeO@cellulose ionomer. Core-shell structured magnetite cellulose nanosphere was synthesized by one step precipitation route and further modified with epichlorohydrin and hexamethylenetetramine. Anion exchange reaction was performed with polytungstophosphate. Synthesized nanocatalyst was characterized with FESEM, FTIR, VSM, EDX and TEM techniques. Vinyl pyridine and three types of functional groups i.e., hydroxyl, thiol, and amine were employed to evaluate the catalyst performance. Results showed that the addition reaction promoted up to 95% within 2h reaction time at moderate temperature (50°C) moreover the nanocatalyst showed good recyclability after three catalytic run as the reaction efficiency was >80% at the end of the third cycle which confirmed high efficiency of the presented system as a green heterogeneous catalyst to synthesis intermediate organic compounds.
由于异相催化反应具有独特的优势，因此在有机合成中越来越多地使用这种类型的化学转化。在各种异相催化体系中，磁性负载离子液体是化学合成中新兴的一种。因此，本研究侧重于开发基于季铵化γ-FeO@纤维素离聚物的迈克尔型加成反应的高效可磁回收催化体系。通过一步沉淀法合成核壳结构的磁铁矿纤维素纳米球，然后用环氧氯丙烷和六亚甲基四胺进一步修饰。用多钨磷酸进行阴离子交换反应。采用 FESEM、FTIR、VSM、EDX 和 TEM 技术对合成的纳米催化剂进行了表征。采用乙烯基吡啶和三种官能团（羟基、巯基和氨基）来评价催化剂的性能。结果表明，在 50°C 的中等温度下，反应 2 小时内，加成反应的转化率最高可达 95%，而且纳米催化剂在经过三次催化循环后具有良好的可回收性，因为在第三次循环结束时，反应效率仍>80%，这证实了所提出的体系作为绿色异相催化剂合成中间有机化合物的高效性。
