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吡啶季铵盐促进的多组份串联反应的研究

The Study of Multicomponent Tandem Reactions Induced by Pyridinium Salts

【作者】 王琦芳

【导师】 颜朝国;

【作者基本信息】 扬州大学 , 有机化学, 2009, 硕士

【摘要】 由于吡啶环的芳香性、碱性、吡啶氮原子的吸电子效应,以及吡啶环在反应过程中是一个很好的离去基团,使得吡啶季铵盐具有丰富的化学反应性质,可以进行亲核加成、Michael加成、1, 3-偶极加成、亲核取代和σ-迁移重排等反应,因此吡啶季铵盐在有机合成化学中有着广泛的应用,是合成杂环化合物的良好合成试剂。另一方面,多组份反应是一种高效的一步合成法,通过多组份的串联反应或多米诺反应,使得几种(三种或以上)简单易得的组份进行一步合成得到一个结构复杂的单一化合物。多组份反应会聚性的合成路线与线性合成法、分步合成法相比显示出很多优越性:分子多样化、分离纯化简单、高效且具有原子经济性,更加接近理想的合成反应,因此在很多领域如有机化学、医药化学和组合化学中得到了广泛的应用。为此我们开展了一系列由现场生成的吡啶季铵盐促进的多组份串联反应的研究,成功合成了具有生物活性的三员环化合物、多取代苯、含氮杂环化合物和2, 3-二氢呋喃衍生物。取得的一些有意义的实验成果如下:1.将芳醛、乙腈衍生物、对硝基溴化苄和吡啶进行了一锅煮反应,室温搅拌,通过现场生成的吡啶季铵盐与芳亚甲基丙二腈再以三乙胺作碱进行反应,制得相应的带有强吸电子基(氰基)的多取代环丙烷类化合物。在此基础上,用预先制备好的吡啶盐(氯乙酰基吗啉吡啶盐和氯乙酰基哌啶吡啶盐)与芳香醛、丙二腈反应也得到了相应的环丙烷衍生物。共得到51个新结构的三员环化合物,其结构都通过NMR、IR、LC-MS等方法的鉴定,并用单晶衍射方法测定了其中6个环丙烷的单晶结构。2.以丙二腈、芳醛、氯乙酸为底物,在乙腈中用吡啶做碱进行多组份反应生成了相应的未见报道的多取代苯。我们以丙二腈、芳醛、氯乙腈为底物,在乙腈中用3-甲基吡啶做碱进行多组份反应,得到了未见报道的多取代苯并含氮杂环化合物。通过NMR、IR、LC-MS等方法的鉴定了21个新结构的多取代苯以及苯并含氮杂环化合物,并用单晶衍射方法测定了其中5个苯并含氮杂环化合物和1个中间体的单晶结构。3.通过芳醛、丙二酸亚异丙酯或者1, 3-二甲基巴比妥酸、活泼溴甲基化合物和吡啶衍生物在室温下搅拌反应,以三乙胺为碱得到一系列未见报道过的内盐化合物。将1, 3-环己二酮、5, 5-二甲基-1, 3-环己二酮和4-羟基香豆素分别与芳醛、活泼溴甲基化合物和吡啶进行加热反应,以三乙胺作碱得到了2, 3-二氢呋喃衍生物。所得到的76个化合物都通过NMR、IR、LC-MS等方法的鉴定,并用单晶衍射方法测定了其中3个化合物的单晶结构。

【Abstract】 Due to the aromatic character of the pyridine heterocycle, its basicity and the electron-attracting influence of the nitrogen atom, and the pyridine core is also a good leaving group, pyridinium salt is found having versatile chemical reactivities. Pyridinium cations can behave as electrophiles and 1, 3-dipoles to take part in condensation, Michael addition, 1, 3-dipolar addition, nuclear substitution and arrangement reactions. Pyridinium salts have vast applications to organic syntheses and especially in the synthesis of heterocycles. On the other hand, multicomponent reaction involving tandem process with at least three different simple substrates has emerged as a powerful synthetic strategy. The multicomponent tandem reactions or domino reactions offer significant advantages over conventional linear-type synthesis and step-by-step synthesis. This methodology allows molecular complexity and diversity to be created by the facile formation of several new covalent bonds in one-pot transformation with easier and less separation and purification. It’s efficient and convenient, and is provided with atomic economy, and is quite closely approaching the concept of an ideal synthesis. So, it has become an important area of research in organic, medicinal and combinatorial chemistry. In this thesis we wish to report our study on the multicomponent reactions induced by pyridinium salts to prepare some cyclopropanes, benzene derivatives, nitrogen containing heterocycles and 2, 3-dihydrofurans with biological activity. A series of significant results and developments have been achieved and the main intriguing results are as follows:1. One-pot multicomponent reactions of pyridine, p-nitrobenzyl bromide, aromatic aldehyde and acetonitrile derivatives at room temperature were used to synthesize cyclopropane derivatives with triethylamine as catalyst. Under the similar reaction, the multicomponent reactions of aromatic aldehyde, pyridinium salts derived from N-(chloroacetyl)morpholine or N-(chloroacetyl)piperidine and malononitrile also yield cyclopropane derivatives. Totally fifty one new cyclopropanes were prepared and characterized by NMR, IR, LC-MS spectroscopy and single crystal structure of six cyclopropanes were confirmed by X-ray diffraction.2. The one-pot multicomponent reaction of aromatic aldehydes, malononitrile and 2-chloroacetic acid and pyridine in refluxing acetonitrile give the unreported five substituted benzenes in moderate yields. And the novel nitrogen containing heterocyclic compounds were produced in multicomponent reactions of malononitrile, aromatic aldehydes, chloroacetonitrile and excessive 3-picoline in refluxing acetonitrile. Twenty one new compounds were fully characterized by NMR, IR, LC-MS spectroscopy and confirmed by single-crystal X-ray diffraction of six compounds.3. Catalyzed by triethylamine the multicomponent reactions of aromatic aldehydes, activated bromomethyl compounds, Meldrum acid or 1, 3-dimethylbarbituric acid and pyridine derivatives in the room temperature produce the unreported zwitterionic compounds. When 1, 3-cyclohexandione, dimedone or 4-hydroxycoumarin was used in the reaction, new cyclohexyl fused 2, 3-dihydrofurans would be formed in high yields. Totally seventy six new compounds were characterized by NMR, IR, LC-MS spectroscopy and confirmed by single-crystal X-ray diffraction of three compounds.

  • 【网络出版投稿人】 扬州大学
  • 【网络出版年期】2010年 01期
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