【作者】 马晓艳；

【导师】 李瑞祥；

【作者基本信息】 四川大学 ， 无机化学， 2007， 博士

【摘要】 加氢反应是合成许多精细化学品的重要手段之一，而阿维菌素和喹啉的加氢在生产实践中有着及其重要的作用。本文致力于合成一系列铱膦配合物并将其用于阿维菌素和喹啉的加氢中，同时，将环境友好的水／有机两相催化体系用于阿维菌素的催化加氢中，取得了一系列具有理论意义和工业应用前景的创新成果。本文合成了一系列铱膦配合物：[IrCl（COD）（MOTPP）]，[IrCl（COD）（TFTPP）]，[IrCl（COD）（BDPX）]，[IrCl（COD）（BDNA）]，[IrCl（COD）（BISBI）]，[Ir（COD）（TFTPP）₂]BF₄，[Ir（COD）（BDPX）]BF₄，[Ir（COD）（BDNA）]BF₄，并用NMR和元素分析进行了表征。将以上配合物连同按文献已报道的[IrCl（COD）（TPP）]，[IrCl（COD）（DPPM）]，[IrCl（COD）（DPPE）]，[IrCl（COD）（DPPP）]一起用于阿维菌素的均相催化加氢。考察了膦配体的电子及空间效应对反应的影响，通过[IrCl（COD）（TPP）]，[IrCl（COD）（MOTPP）]，[IrCl（COD）（TFTPP）]做催化剂对阿维菌素的催化加氢研究，发现含吸电基团的膦配体所形成的配合物表现出较高的加氢活性，但选择性较差。不含取代基团的TPP配合物既有较高的加氢活性，同时保持较高的选择性。通过对含不同螯合骨架的配合物对阿维菌素加氢反应的研究，发现过大的膦配体螯合骨架不利于加氢反应的进行，生成了更多的副产物—阿维菌素糖苷，这是由于在配合物中，当膦配体的螯合骨架过大时，不利于COD从配合物中解离，因而活性中间体难以形成，使加氢反应受到抑制，结果引起副反应增加。本文通过研究，提出了阿维菌素加氢的副产物阿维菌素糖苷的形成原因是由于在加氢过程中，氢分子发生异裂所致，并通过添加三乙胺使副反应得到了抑制。离子型配合物的加氢活性较差，是由于离子型配合物的加氢过程要经过[Ir（ol）₂L₂]⁺ （ol=olefin）过渡态，对于阿维菌素这样的大分子底物，生成这样的过渡态空间位阻较大，因而加氢产率下降。过量膦配体的加入使加氢活性有所降低，这是由于过量膦配体将占据配合物的配位空位，抑制了底物与中心金属的配位，从而使加氢活性降低。喹啉作为石油化工生产中重要的加氢去氮过程（HDN）的模板反应受到了人们的广泛关注，同时，将喹啉直接加氢也是制备药物中间体1，2，3，4-四氢喹啉最简便有效的合成方法。本文将合成的铱膦配合物以及[IrCl（COD）（TPP）]，[IrCl（COD）（DPPM）]，[IrCl（COD）（DPPE）]，[IrCl（COD）（DPPP）]，[Ir（COD）（TPP）₂]BF₄，[Ir（COD）（DPPM）]BF₄，[Ir（COD）（DPPE）]BF₄，[Ir（COD）（DPPP）]BF₄用于喹啉的加氢反应研究，发现这些配合物都有很好的加氢活性，能在温和条件下（85℃，1MPa）将喹啉完全转化为1，2，3，4-四氢喹啉，没有其它副产物的生成。同时，研究发现不同膦配体的配合物加氢活性各有差异，我们因此得到了膦配体的电子效应和空间效应对喹啉加氢反应的影响，当膦配体含有吸电基团时，有更高的加氢活性；膦配体空间结构变化表明，膦配体螯合环与螯合骨架对喹啉加氢的影响不大。我们还发现离子型的配合物比相应的含氯原子配位的相应配合物具有更高的加氢活性。我们以[Ir（COD）（TPP）₂]BF₄为催化剂来研究喹啉加氢，并将原位核磁技术用于反应中间体的跟踪和研究，分离表征了相应的中间体，提出了喹啉加氢的反应机理。发现喹啉与[Ir（COD）（TPP）₂]BF₄在常温下迅速发生配位，生成了[Ir（COD）（Q）（PPh₃）₂]BF₄，随后氢分子在常温、常压下被活化，生成中间体[Ir（H）₂（Q）₂（PPh₃）₂]BF₄。我们用[Ir（H）₂（Q）₂（PPh₃）₂]BF₄做催化剂直接与喹啉反应，发现它的催化活性和[Ir（COD）（TPP）₂]BF₄大致相同，证明它是参加反应的中间体。随后我们做了关于反应温度对转化率影响的实验，发现反应温度对加氢有重要的影响。因此，我们推断催化循环的决速步骤不是[Ir（COD）（Q）（PPh₃）₂]BF₄和[Ir（H）₂（Q）₂（PPh₃）₂]BF₄的生成，而是已经配位了的氢原子向喹啉杂环上C=C键的转移。根据这个结论，解释了膦配体的螯合骨架大小对加氢反应没有影响的原因。以水溶性有机金属配合物为催化剂的两相催化体系是“绿色化学”中发展迅速的前沿研究领域之一。它一方面具有均相催化体系高活性，高选择性的优点，另一方面又解决了均相体系中产物与催化剂分离难的问题。我们合成了一系列水溶性的膦配体，并和[RhCl（COD）]₂在原位条件用于水／有机两相体系中阿维菌素的催化加氢，并考察了复合体系中不同的水溶性膦配体、反应温度、压力、表面活性剂的种类及浓度，添加离子等对该反应的影响。研究结果发现：在相同条件下，BISBIS具有最好的转化率。双长链表面活性剂与其它表面活性剂相比较，能很好的促进阿维菌素加氢反应的进行，并且随着表面活性剂浓度的增加，胶束的增溶作用增加，使底物与催化剂能更充分的接触，从而转化率也相应增加。溶剂的量对催化加氢反应影响较大，选择适当比例的甲苯、乙醇、水可以促使双连续相的形成，从而提高反应的转化率和选择性。温度，膦／铑比，催化剂的浓度，无机离子和NEt₃的添加都会对反应催化活性和选择性产生重要的影响。更多还原

【Abstract】 Hydrogenation is one of the main methods to produce a large number of fine chemicals. Inthis thesis, a series of iridium-phosphine complexes [IrCl（COD）（MOTPP）], [IrCl（COD）（TFTPP）],[IrCl（COD）（BDPX）], [IrCl（COD）（BDNA）], [IrCl（COD）（BISBI）], [Ir（COD）（TFTPP）₂]BF₄,[Ir（COD）（BDPX）]BF₄, [Ir（COD）（BDNA）]BF₄, were synthesized and identified by ³¹p, ¹H-NMRspectra and elemental analysis. These complexes were applied in the hydrogenation ofavermectin and quinoline. The water-soluble rhudium-phosphine complexes formed in situ wereemployed in hydrogenation of avermectin in aqueous-organic biphasic system.In order to understand the effect of electron factors and steric structures on thehydrogenations of avermectin and quinoline, another four complexes, [IrCl（COD）（TPP）],[IrCl（COD）（DPPM）], [IrCl（COD）（DPPE）], [IrCl（COD）（DPPP）] were prepared by the reportedmethod.The results show that iridium complexes beating electron-withdrawing phosphine exhibitshigher activity and lower selectivity for the hydrogenation of avermectin. Complex bearing TPPhas both high activity and high selectivity. On the one hand, the iridium complexes containingbulky phosphine is not favorable for this hydrogenation and a high content of by-productavermectin aglycon is formed. The reasonable explaination is bulky ligand is not favorable for COD dissociation in iridium complex and the active species is difficult to generate, so thehydrogenation is suppressed and the formation of byproduct is promoted. Furthermore, thereason for the formation of avermectin aglycon is related to the heterolytic split ofη²-H₂ incomplex. The heterolytic split ofη² -H₂ in complex causes the formation of H⁺, which lead tothe split of C-O bond in avermetin. The cationic complexes exhibit low activities as they undergothe intermediate [Ir（ol）₂L₂]⁺ （ol=olefin） in the hydrogenation process.Besides being as an important model for the study of HDN process in petroleum industry, thehydrogenation of quinoline to form tetrahydroquinoline or its derivatives is important syntheticintermediate and structural unit of alkaloid. To direct hydrogenation of quinoline would be themost convenient route to obtain tetrahydroquinoline derivatives. In this thesis, we employediridium complexes mentioned above as catalysts for the hydrogenation of quinoline. The resultsshow that all these complexes are efficient catalysts for quinoline hydrogenation and they couldcompletely convert quinoline into 1,2,3,4-tetrahedroquinoline under mild conditions （85℃, 1MPa,5 hours） without any byproduction formation. The differences of catalytic activities of thesecomplexes provide us with the informations about the electronic and steric effects. The resultsindicate that complex bearing a electron-withdrawing ligand has higher activity and the stericeffect of ligand has little influence on quinoline hydrogenation. The results also show that thecationic complexes exhibit higher activities than their corresponding complexes containingchloride in the similar conditions..Employing [Ir（COD）（TPP）₂]BF₄ as a catalyst, we detect the intermediates in thehydrogenation process of quinoline by means of NMR insitu. The results show that quinolinereacts rapidly with [Ir（COD）（TPP）₂]BF₄, and then hydrogen is activated to produce intermediate[Ir（H）₂（Q）₂（PPh₃）₂]BF₄ at room temperature. [Ir（H）₂（Q）₂（PPh₃）₂]BF₄ was isolated and employedas catalyst to hydrogenate quinoline and its activity was almost the same as [Ir（COD）（TPP）₂]BF₄.The effect of react temperature on the hydrogenation was investigated and shows significantinfluence. Based on the research results, the rate-determining step is not the formation of[Ir（COD）（TPP）₂]BF₄ or [Ir（H）₂（Q）₂（PPh₃）₂]BF₄ in the mechanism.The catalytic reaction in organic/aqueous two-phase catalytic system is one of the frontierfields in the "Green Chemistry". On the one hand, it has the merit of high activity and selectivityof homogeneously catalytic system. On the other hand, it solves the problem of the separation of catalyst from the production. A series water-soluble phosphine ligands were synthesized andcoordinated with [Rh（COD）Cl]₂ in situ to catalyze the hydrogenation of avermectin. The effectsof ligand structure, reaction temperature, hydrogen pressure, the surfactant concentration, andinorganic salt were investigated.The results show that Rh-BISBIS exhibits the best activity. Thedouble long chain cationic surfactants could efficiently promote the hydrogenation. The volumeof solvent has a significant influence on this hydrogenation and appropriate ratio of toluene,ethanol, and H₂O would cause the formation of bicontinous phase and improves the reactionconversion and selectivity. The additions of inorganic salt and organic base Et₃N could stronglyinfluence the reaction activity and selectivity.更多还原