【作者】 徐纪敏；

【导师】 胡跃飞；

【作者基本信息】 清华大学 ， 化学， 2010， 博士

【摘要】 ]含氮芳香化合物是一类非常重要的有机化合物,他们广泛存在于天然产物、药物活性分子和有机材料结构中。因此,含氮芳香化合物的合成一直以来都是人们关注的热点。近几十年来,这类化合物的合成已经取得了很多重要进展。尽管如此,随着这类化合物应用的扩大,需要发现更多简单高效的合成方法。本论文主要研究了邻芳基取代吡啶、芳基取代哌啶、多芳基取代中氮茚、三芳胺等几类含氮芳香化合物的合成新方法,取得了以下研究成果:建立了一种全新的钯催化的N-苯甲酰甲基吡啶盐直接邻位芳基化体系。该体系的显著特点是反应结束后活化基团能够从芳基化的底物自动离开。同位素实验表明反应通过C-H活化的途径进行。实验和DFT计算表明N-苯甲酰甲基起到了两个关键作用:1)通过形成叶立德活化吡啶分子;2)通过与钯的配位控制芳基化的位置。建立了一种简单高效的Pd/C-PtO₂双金属催化氢化体系,实现了对芳基取代吡啶的催化氢化。在偕二氯化合物存在条件下,利用Pd/C较强的催化氢化去氯能力和PtO₂对吡啶环较强的还原能力,在温和条件下制备了芳基取代哌啶盐酸盐。建立了一种新型的2,3-二芳基取代中氮茚的合成方法。该方法以2-甲基-N-苯甲酰甲基吡啶盐和溴代芳烃作为底物,在Pd（OAc）₂/PPh₃催化体系的作用下,实现了2,3-二芳基取代中氮茚的合成。这种方法是对目前所存在的取代中氮茚合成方法的重要补充。建立了一种三芳胺类化合物的合成方法。该方法不需要加热,不使用配体和碱,只需在Cu（OAc）₂的作用下,邻氨基苯酚和芳香硼酸在甲醇中常温搅拌就可制备三芳胺化合物。此外我们讨论了邻氨基苯酚作为底物的特殊性。另外,本论文还开发了一种简单、高效、通用的苯酚类化合物的合成体系。这个体系反应条件简单,只需采用易得的苯硼酸作为原料,在简单铜催化剂的作用下室温水中即可短时间内高产率的制备苯酚化合物。更多还原

【Abstract】 Nitrogen-containing aromatic compounds are important family in organic chemistry and have important applications in the preparations of natural products, drugs and chemical materials. Therefore, development of synthetic methods for nitrogen-containing aromatic compounds is an important and interesting project. In past decades, great progesses have been made for this purpose. In this dissertation, several novel synthetic methods were studied, by which nitrogen-containing aromatic compounds including ortho-arylated pyridines, arylated piperidines, aryl-substituted indolizines and triarylamines were prepared. We have obtained some important results as follows:A novel Pd-catalyzed direct ortho-arylation of N-phenacylpyridinium bromide was developed. Its unique feature is that the activating group can depart from the arylated pyridines automatically. A kinetic isotope effect study proved that the reaction went through a C-H bond activation pathway. The results from experiments and DFT calculations indicated that the N-phenacyl group played two crucial roles: 1) activation of the pyridine ring by forming an ylid and 2) regioselective control of the arylation by coordination with Pd at the ortho-position of pyridine.A simple and efficient Pd/C-PtO₂ bimetallic catalytic hydrogenation system for the hydrogenation of arylated pyridines was developed. In the present of geminal dichloroalkane, Pd/C has strong ability in hydrodechlorination reactions and PtO₂ is an ideal catalyst for the reduction of pyridine nuclei. Thus, a series of arylated piperidines were prepared by hydrogenation of arylated pyridines smothly under mild conditions.A novel catalytic method for the synthesis of 2,3-diaryl-substituted indolizines was developed. Thus, a series of 2,3-diaryl-substituted indolizines were prepared from 2-methyl-N-phenacylpyridinium bromide and bromo-aromatics in the present of Pd（OAc）₂/PPh₃ in one-pot reaction. The method characterized with simple procedures, mild conditions, and high yields, which is an important addition for the existed methods in the synthesis of indolizines.A convenient synthestic method for triarylamines was developed, by which highly steric triaryl amines were prepared smoothly at room temperature by using Cu（OAc）₂ as catalyst and o-aminophenol and aromatic bronic acids as substrates. The contional experiments proved that the hydroxyl group in o-aminophenol is necessary.Finally, a general and efficient procedure for the preparation of phenols was developed by a copper-catalyzed direct hydroxylation of arylboronic acids at room temperature in water. The method is characterized by the use of a cheap catalyst, mild conditions, simple performance, short reaction time and high yield results.更多还原