【作者】 刘洁；

【导师】 李毅群；

【作者基本信息】 暨南大学 ， 应用化学， 2010， 硕士

【摘要】 高分子负载催化剂稳定性高、腐蚀性小、易从反应体系中分离回收、可重复使用、有较高的催化活性和立体选择性,具有重要的工业应用价值。本文利用廉价易得的聚氯乙烯做载体,通过功能化负载过渡金属钯研究其在碳碳偶联反应中的催化性能。本论文分为四章。第一章概述了高分子负载催化剂的特点、种类及其在有机合成中的应用。第二章研究了聚氯乙烯负载希夫碱负载纳米钯催化剂对Suzuki反应的研究。实验结果表明,催化剂中钯粒子为纳米级,在乙醇中催化Suzuki反应,具有反应时间短、产率高、催化剂易回收等优点。反应结束后,催化剂可重复使用6次催化产率没有明显下降。第三章利用已制备的聚氯乙烯负载希夫碱负载纳米钯催化剂继续研究其对Heck反应的催化。结果表明,在DMSO中反应可以取得良好的效果,催化剂可重复使用6次。第四章用2-巯基苯并噻唑作为载体连接在聚氯乙烯上,合成含有氮、硫的二齿配体聚合物配体,用于负载纳米钯催化剂,并研究了其对Suzuki反应的催化作用。实验结果表明该催化剂具有很高的反应活性,催化剂可重复使用5次,产率基本不变。总之,上述催化反应具有催化剂易于制备、反应条件温和、选择性好、产率高、操作简单、催化剂可以回收使用和对环境友好等优点,符合绿色化学的要求。本论文的研究工作进一步扩展了负载催化剂在有机合成中的应用。更多还原

【Abstract】 Polymer-supported catalysts have high stability, low corrosion, and easy to be recovered from the reaction system and reused. Therefore, polymer-supported catalysts have important academic and industrial applications, due to their high catalytic activities and selectivities. It is well known that poly(vinyl chloride) (PVC) is a widely used inexpensive and easily modified by functional group via displacement reaction directly without chloromethylation makes its suitable polymeric supports for heterogeneous catalyst. We explored the catalytic activities of palladium nanoparticles immobilized on the functionalized PVC in this thesis. This thesis is divided into four chapters.In chapter 1, one briefly introduce about the characteristics of polymer-supported catalysts, as well as their variety and application in organic synthesis.In chapter 2, we have prepared and character the functionalized polymer of PVC-supported Schiff base (abbreviated as PVC-EDA-SA) were prepared from PVC with sequential attachment of ethylenediamine and salicylaldehyde and further use it as support to immobile palladium nanoparticles. The as-prepared catalyst was found to be air and moisturestable and to have significant catalytic activity in Suzuki-Miyaura reactions under mild operating conditions. Various phenyl halides were coupled with phenylboronic acid in aqueous ethanol, under air, to afford the corresponding cross coupled products in good yields. Furthermore, the catalyst can be easily recovered by simple filtration and reused for up to five cycles without losing its activity.In chapter 3, we used the as-prepared PVC-EDA-SA-Pd0 catalyst mentioned above to continue to explore its catalytic performance in Heck reactions. The results showed that excellent yields obtained from DMSO, the catalyst can be reused for six times.In the last chapter, on the polymer surface of poly(vinyl chloride) supported a bulky, inexpensive and simple bidentate ligand 2-mercaptobenzothiazole (PVC-MBT) were achieved by a simple procedure. The as-prepared catalyst (PVC-MBT-Pd0) was found to be air and moisture stable and exhibits significant catalytic activity for Suzuki-Miyaura reactions under milder operating conditions. The catalysts showed excellent activity towards Suzuki coupling reaction of different aryl iodides and bromides with phenyl boronic acid using ethanol as solvent in short reaction time. Furthermore, the catalyst can be easily recovered by simple filtration and repeatedly reused for at least 5 cycles with comparable yields. In summary, the synthetic methods mentioned above possess the advantages such as catalysis can be readily prepared, mild reaction conditions, simple operation, high selectivities, excellent yields, and moreover, the potential for recycling of catalysts is benign to environment.更多还原