【作者】 孙国栋；

【导师】 张锁秦；

【作者基本信息】 吉林大学 ， 有机化学， 2009， 硕士

【摘要】 本文设计了一种以硅胶嫁接丙烯酸做为载体固载的DMAP催化剂S-PAA-DMAP。其合成路线以吡啶为原料,首先将吡啶通过氧化,硝化得到N-氧化硝基吡啶2,还原后得到4-氨基吡啶3,再与两分子丙烯酸甲酯通过迈克尔加成得到化合物4,再在甲苯中通过强碱甲醇钠的作用发生克莱森酯缩合,然后在20%盐酸作用下脱羧得到1-吡啶基-4-哌啶酮,再在50%的乙醇溶液中与盐酸羟胺生成肟5,再在甲醇中以雷内镍作催化剂加氢还原得到6,在与Boc保护的6-氨基己酸反应后得到化合物7,经脱保护后得到末端带有氨基的DMAP类似物8。将DMAP类似物8与硅胶嫁接丙烯酸连接后得到了我们设计的催化剂S-PAA-DMAP。在催化实验部分我们用设计合成的催化剂S-PAA-DMAP催化了环己二酮衍生物的Fries重排反应和α-苯乙醇的乙酰化反应都得到了较好的效果。在Fries重排实验中我们用了底物30%mol的催化剂反应6~8h即可使原料转化完全。苯乙醇的乙酰化反应中使用10mol%的S-PAA-DMAP能够达到与DMAP相近的效果,催化剂重复利用五次分别得到了91%,88%,84%,82%及82%的产率,表明了S-PAA-DMAP具有良好的催化稳定性。更多还原

【Abstract】 Polymer catalysts are referring to all of the polymer materials with catalytic activities in chemical reactions,which is an important branch of functional polymer materials. By the inspiration of Merrifield solid phase synthesis,the organic polymers (polystyrene sulfuric acid) loading ([Pt (NH3)4 ]2+) complex catalyst finally came out . This research work immediately sparked widespread concern and interest of catalytic scientists around the world, since then Polymer-supported catalytic complex catalysis has become an independent field of cross-disciplinary research. In the subsequent 30 years people have designed and synthesized a large number of Polymer-supported catalysts with different structures and different uses, and due to the polymer effect among the various functional groups in the polymer chain, such as synergy, some have special optically active structures, and their catalytic activity in selective catalysis were much higher than the corresponding homogeneous small molecules catalyst.In a large number of small-molecule catalysts ,4-N, N dimethylamino-pyridine (DMAP), due to its strong nucleophilicity is often used as a catalyst for a number of important reactions, such as acylation, silylation, triphenyl methylation, and ester rearrangement, Darkin-West reaction, Baylis-Hillman reaction. However, because of its belonging to small organic molecules, DMAP does not facilitate the recovery and utilization, resulting in wasted costs. In order to change this situation many researchers have grafted it to low-cost commercial materials, such as organic polymer resins, inorganic materials (silica gel and molecular sieve), and micro-capsules. We found that either the soluble homogeneous catalysts or the insoluble heterogeneous catalysts had more or less deficiencies when they were recycled. By comparing a variety of supported DMAP catalysts in the literature, we designed to combine the single soluble homogeneous catalysts and the insoluble heterogeneous catalysts, based on such considerations we have chosen silica gel grafted polyacrylic acid, which is a combination of silica gel and polyacrylic acid, as the carrier to immobilize DMAP. This carrier will set the advantages of organic polymer and silica gel in one: the linear long chain polyacrylic acid polymer is soluble in a variety of solvents, and can extend freely in the reaction solvent system, so the catalyst can be fully utilized. While the silica is insoluble, so the silica supported catalyst can be filtered directly when the reaction is completed, and can be facilitate recycled. We use the coupling agentγ-amino propyltriethoxysilane to graft silica gel and polyacrylic acid polymer in our design. This design combines the advantages of both while cleverly avoiding its shortcomings.In this paper, we designed to use pyridine as the raw materials. First we got nitropyridine N-oxide 2 through the oxidation and nitration, after reduction we got 4-aminopyridine 3, which then reacted with two molecules of methyl acrylate through the Michael addition to generate compound 4. 1-pyridyl-4-piperidine-one was synthesized via Claisen ester condensation and decarboxylation from 4, and then reacted with hydroxylamine hydrochloride in 50% ethanol solution to generate oxime 5. Compound 6 was obtained by hydrogenation in methanol using Raney nickel as the catalyst, which reacted with Boc-protected 6-aminocaproic acid to generate compound 7, the amino-terminal with DMAP analogue 8 was obtained by deprotection. S-PAA-DMAP was finally synthesized by connecting the DMAP analogue 8 and silica gel grafting polyacrylic acid.To study the catalytic performance of S-PAA-DMAP catalyst, we chose Fries rearrangement and the acetylation ofα-phenylethanol as our model reaction in the catalytic part of our experiment. In Fries rearrangement we used 30% mol catalyst for reaction 6~8h to make raw materials completely transformed. Inα-Phenylethanol acetylation we used 10% mol both of S-PAA-DMAP and DMAP to achieve similar results. The catalyst was reused three times, to get a result respectively, 91%, 86% and 84% in yield. S-PAA-DMAP has a good stability as a catalyst, which put forward a new mode of thinking for the future work of the immobilized catalyst.更多还原