【作者】 周宝晗；

【导师】 吴安心；

【作者基本信息】 华中师范大学 ， 有机化学， 2007， 博士

【摘要】 拓扑异构体是一类崭新的同分异构现象。是分子结构理论与应用研究中的新课题。同步合成出多样性的拓扑异构体，是开展拓扑异构体之间波谱性质的比较、结构分析、鉴别方法、相互转化及选择性合成工作的基础。本文利用一锅煮的方法同步合成出六个基于二乙酯基甘脲的C型与S型折叠态的拓扑异构体，利用经典的手段¹H NMR和¹³C NMR，IS，UV，SEM首次对合成的C-shaped和S-shaped六种拓扑异构体进行了结构表征和分析，发现对于不同拓扑结构的C-shaped和S-shaped可以通过¹H NMR来区分，而对于相同拓扑结构的S-shaped分子cis（SC）和trans（（±）ST）分子；C-shaped的cis（CC）和trans（（±）CT）分子，则要结合¹³C NMR来鉴别，六种拓扑异构体的IR，UV，SEM则没有明显的区别。并且我们得到了六种拓扑异构体的晶体结构。证实了我们利用经典的手段分析是正确的。利用同样的方法，我们合成并衍生出类似结构化合物或同系物分子，试图构建一个以拓扑结构多样性为特色的化学库。我们通过四个（拓扑对映体作为混合物来用）拓扑异构体及部分中间体中间体进行了生物活性筛选，发现四种拓扑异构体的杀菌活性没有明显的差异。而除草活性则出现较大的差异。C-shaped的cis（CC）无论对双子叶植物油菜还是单子叶植物稗草均表现出很好的抑制作用，而其他的异构体则只是在一定浓度时对某一种草有较好的活性。这也是首次开展调查和筛选拓扑异构体的生理活性的研究工作。另外，基于原子经济性的要求，如何选择性的得到预期的3D结构的分子是本文重点开展的另一个研究课题一拓扑选择性合成的研究，这是一个全新的前沿性课题，文献报道极少。我们尝试研究反应时间，反应温度和建筑板块的三维构型对拓扑异构体选择性生成的影响，以及各个拓扑异构体在产物中的分布规律，探讨拓扑选择性合成中可控制方法。在拓扑选择性合成的研究中，通过反应条件的改变，我们发现延长反应时间和提高反应温度（高压下）可以选择性的得到C-shaped的产物。除此之外，根据组装模块环醚本身的三维空间构型，利用其拼接的角度，伸展的方向，从而进行化学反应并选择性得到了预定结构的建筑C-shaped分子。而且，基于拓扑异构体之间三维立体结构的不同，C型与S型分子在分子识别，组装等方面存在一定的差异。本论文也详细研究了C-shaped的分子（亦可以称为分子夹）对中性芳香客体的识别作用，通过大量的实验，我们发现我们这种4U的分子夹对对苯二酚等客体分子具有很好的识别作用，它们之间的弱相互作用力主要是主体分子的边墙和客体分子苯环之间的π-π相互作用，以及主体分子甘脲上面的脲羰基和客体分子的羟基之间形成的氢键。这些作用力可以通过¹H NMR，IR的变化表现出来。这是第一个对对苯二酚有着良好识别性能的人工合成的分子夹受体，和Nolte的3U的分子夹对间苯二酚的识别有着明显的区别。我们分别通过¹H NMR，IR，JobPlot，Dilution titration等手段对形成的包结物进行了表征，并初步推断了其相互作用的机理。更多还原

【Abstract】 Topological isomers are brand-new phenomena in molecular structures, which can bring new subjects to Molecular Structural Theory. The studies on the spectrum properties, structure analysis, translation, and selective synthesis are based on synthesis of diverse topological isomers in one pot. According to our investigation, few reports focus on the synthesis of multiple topological isomers in one pot.In this thesis, six topological isomers based on diethoxycarbonyl glycoluril were synthesized in one pot, whose chemical configurations were characterized by means of ¹H NMR, ¹³C NMR, IR, UV and SEM. It was found that the topological configuration of C-shaped and 5-shaped molecules could be identified by ¹H NMR, and the topological isomers of S-shaped cis （SC） and trans （（±） ST）, C-shaped cis （CC） and trans （（±） CT） could be identified by ¹³C NMR. There is little difference in IR, UV and SEM of six topological isomers. What’s more, the X-ray structures of all the six topological isomers were obtained, which further confirmed our analysis of classical means were correct. In addition, we synthesized a series of compounds with the similar structure under similar conditions. These compounds constitute a chemical library based on diverse topological structures to screen new drugs, which has significance in the preparation of pharmaceuticals. Little attention has been paid to the bioactivity of the topological isomers in previous work. So we investigate the preliminary bioassays of the six topological isomers. The results showed that the six isomers exhibited obvious difference in herbicidal activity. At the dosage of 100mg litre^-1, CC showed 100% inhibitory rate not only to the root of the rape but also to the root of barnyard grass, what’s more, CC showed excellent herbicidal activity to the stalk of the rape and the stalk of barnyard grass, inhibitory rate is 100% and 94.2% respectively. However, besides （±） ST showed good herbicide activity to the root of the rape （inhibitory rate 93.5%）, other isomers （SC, （±） CT） showed general herbicidal activity. There is little difference in antifungal activity.With the emphasis on the research for atom-efficient transformations of easily available starting materials into complex organic molecules, nowadays how to selectively synthesize one of the desired well-defined 3D molecular structures becomes a new bottleneck to chemists. Here we investigate the effect of reaction time, temperature and the 3D structure of the building block on the topological selective formation of multi-topological isomers. A modified synthetic method in which the desired C-shaped molecules could be selectively obtained under high pressure in short reaction time or elevating the reaction temperature is presented.The C-shaped molecules, also referred as molecular clips, have many applications in molecular recognition, assembly etc. After C-shaped molecules are synthesized selectively, we studied the binding properties for neutral guest molecules. The complexes were characterized through ¹H NMR, IR and Dilution titration. Their unique binding behavior towards hydroquinone, which is different from Nolte’s clips （high affinity for resorcinol）, has been investigated in details. There exists hydrogen bonds andπ-πstacking interactions in binding process similar to Notle’s clips. But compared with Notle’s clips, our molecular clips possess four oxygen atoms as binding sites. According to the calculated distances of the oxygen atoms, we assumed that our molecular clips might bind hydroquinone through bifurcated hydrogen bonds. Job-plot analyses are performed to determine the stoichiometry of the complexes and provide good evidence of a 1:1 stoichiometry for the complexes.更多还原