【作者】 赵娜；

【导师】 吴养洁； 李铁生；

【作者基本信息】 郑州大学 ， 有机化学， 2013， 博士

【摘要】 本论文研究了两亲性芳香亚胺环钯化合物的合成、表征及其在均相条件下催化Suzuki反应和Heck反应的催化性能；两亲性芳香亚胺环钯化合物及其聚合物的Langmuir-Blodgett(LB)膜的制备、表征以及非均相催化Suzuki偶联反应的催化性能；芳香亚胺环钯自组装(self-assembly)膜的制备,表征及催化Suzuki偶联反应。1.合成了系列两亲性芳香亚胺环钯化合物(3a-c)(Scheme1),并通过核磁氢谱,碳谱,红外光谱,质谱以及元素分析对其结构进行鉴定。该类化合物可以在空气中稳定存在。研究了均相条件下该环钯催化剂在Heck和Suzuki偶联反应中的催化活性。实验表明,在DMF溶剂中,只需要0.1mol%的催化剂即可催化Heck反应。在纯水相中加入四丁基溴化铵作为相转移催化剂时,该催化剂适用的底物更广,可以得到比有机相更好的催化效果。研究了该催化剂对芳基溴代物和芳基硼酸的Suzuki反应的催化活性。在水相中,0.1mol%催化剂就能很好的催化该反应。2.制备了两亲性芳香亚胺环钯化合物(3a-c)的LB膜,对其成膜性能和表面形态进行表征。研究了该LB膜催化剂在溴代芳烃和芳基硼酸的Suzuki偶联反应中的催化性能。结果表明,该催化剂在较温和的条件下可以高效的催化该反应,催化剂的转化数(TON)和转化率(TOF)值分别为250000和8333h-1。该LB膜催化剂的催化效率是均相催化剂的7倍,并且可循环使用3次。催化剂在载体上的排列方式和空间取向与其催化性能有很重要的关系。均匀有序排列的LB膜催化剂可以更好的催化偶联反应,与均相催化剂相比有更好的催化活性。3.合成了一系列两亲性芳香亚胺环钯聚合物,并制备其LB膜,对其成膜性能、表面形态以及在对溴甲苯和芳基硼酸的Suzuki偶联反应中的催化性能进行初步研究。结果表明,在相同的催化条件下(纯水相,50度,30小时),聚合物LB膜的催化活性远远低于单体LB膜。这是由于聚合物单分子转移性能较差,在电极上的电子转移也受到一定阻碍,导致其催化活性大大降低。4.合成了一系列亚胺环钯自组装膜(PdLl-5)(Scheme2),并对膜表面的化学组成与表面形态进行研究。环钯自组装经过亲水处理,硅烷化,亚胺化和环钯化四个过程进行制备,其水接触角从20。增加到82。；利用红外光谱,X-射线光电子能谱对其制备过程进行结构证明；电化学实验证明,在ITO导电玻璃上的自组装膜的循环伏安图上出现三对氧化还原峰,表明是Pd0/PdⅡ的氧化还原过程；原子力显微镜和扫描电镜图像显示自组装单层膜均匀,平整,无明显的缺陷。膜表面化合物分布整齐,颗粒大小均匀,直径均为2nm左右。5.研究了系列芳香亚胺环钯自组装膜在Suzuki偶联反应中的催化性能。实验证明,该催化剂在较温和的条件下能够高效的催化溴代芳烃和芳基硼酸的偶联反应并与该自组装膜催化剂结构相似的分子催化剂1与其催化性能进行比较。结果表明该自组装膜催化剂在异相条件下的催化效率是其均相类似物的10倍,并且循环使用5次都可以取得很好的产率,活性也没有明显降低。循环5次后,仍有至少90%的催化剂可以回收。将催化剂直接组装在圆底烧瓶内表面,既可以作为催化剂又是反应器,大大简化了反应步骤。这样的圆底烧瓶可以循环8次而不降低催化活性。经过一系列的催化活性测定分析,初步提出了该异相催化的机理。更多还原

【Abstract】 In this thesis, the synthesis, characterization of a series of novel amphiphilic cyclopalladated arylimines were reported; Langmuir-Blodgett (LB) films of these cyclopalladated arylimines monomers and their polymers were successfully fabricated and characterized. Heck reaction and Suzuki reaction catalyzed by these complexes in homogeneous and heterogeneous system were also investigated, in which their LB films transferred onto hydrophilic glass substrates exhibited high catalytic activity; A series of cyclopalladated arylimine self-assembly films were prepared via chemical grafting to substrates and utilized for catalyzing Suzuki coupling reaction.1. A series of amphiphilic cyclopalladated arylimine compounds3a-c were prepared and characterized by IR, UV,1HNMR,13CNMR and MS (Scheme1). These conpounds in air were very stable due to not sensitive to oxygen. Their catalytic properties for Heck and Suzuki cross-coupling reactions were investigated in homogenous system. The Heck reaction catalyzed in the presence of0.1mol%catalyst in DMF was completed with high yield. These catalysts could be applied to wider scope’s substrates in pure water. For activated and inactivated aryl bromides and aryl boric acids in Suzuki reaction, excellent yields were obtained in pure water. 2. The LB films of amphiphilic cyclopalladated arylimines were fabricated, characterized and used for catalyzing the Suzuki reaction in heterogeneous system. The results of catalysis for4-bromotoluene and phenyl boronic acid showed that one-layer LB films of3c deposited onto solid slides was efficient for the Suzuki reaction and catalyst content in the LB films was as low as0.001mol%. The TON and TOF of the substrates were250000and8333h-1. The heterogeneous catalysts exhibited7times enhanced catalytic performance compared with that in the homogeneous ones. The catalysts were easily recoverable and could be reused three times for Suzuki reactions.3. A series of amphiphilic cyclopalladated arylimine polymers were prepared and their LB films were fabricated. The film-forming property and morphology of the polymers were investigated. The results showed that catalytic activity of the polymer LB films were lower than the monomer LB films in the same condition (50℃,30h in pure water). It was likely that the poor transfer and easy aggregation of polymer monomer were the reason that resulted in the low catalytic activity.4. A series of cyclopalladated arylimine self-assembly films were prepared via chemical grafting to substrates (Scheme2). There were four steps in the self-assembly:hydrophilic treatment, silanization, imine generation and cyclopalladate grafting. The contact angle increased from20to82°. ATR-IR and XPS were used to analyze the composition of the heterogeneous catalysts. Three reduction peaks correspond to the reduction reactions of PdⅣ/Pd0in CV experiment. The cyclopalladated compound formed a uniform layer with domains and a few defects on the SAM and AFM. The domains were uniform and had a diameter of approximate2nm. 5. These immobilized complexes could be used as efficient and reusable catalysts for the Suzuki coupling of4-bromotoluene and phenylboronic acid under air condition in water. The catalytic reaction was indeed heterogeneous. By the heterogenization of the catalysts, their activities were not only improved compared to homogeneous catalyst1, but it also exhibited a much more improved stability over time. The heterogeneous catalyst obtained exhibited10times enhanced catalytic performance compared with the homogeneous counterpart. The Pd catalysts were grafted onto the internal surface of the round bottomed flasks. The flasks were not only the reactors but the catalysts, which simplified the reaction operations. The as-synthesized catalysts could be used8times without losing activity. The mechanism of the heterogeneous catalysis was proposed preliminarily.更多还原