【作者】 彭游；

【导师】 陈淑华；

【作者基本信息】 四川大学 ， 有机化学， 2003， 硕士

【摘要】 人工分子识别研究是生物有机化学前沿富有挑战性的领域之一。本文致力于新型手性与非手性偶氮酰胺类主体的设计与合成、单手性臂脱氧胆酸甲酯类碗形主体的设计与微波合成、芳杂环分子钳的设计与微波固相合成及其对中性分子和手性分子的识别与对映选择性识别性能研究，取得了一系列具有重要学术意义与应用前景的创新性成果。 设计合成了偶氮、胆甾、芳杂环三个大类四个系列共23个主体，其中手性偶氮类主体为首次设计与合成。深入研究了它们的合成方法，实现了多种简便有效的选择性合成，特别是在芳杂环分子钳的合成中，成功地采用微波固相反应，缩短了反应步骤，提高了产率，实现了一种对环境友好的，具有绿色化学意义的人工主体的合成新方法。所合成的主体具有不同的裂穴大小、不同识别位点、不同刚柔度以及不同的手性中心，其结构经IR、¹HNMR、MS、和元素分析所确证。 利用紫外光谱滴定法研究了主体分子在CHCl₃或CH₃CN中对中性分子、手性分子的识别性能，测定了配合常数及自由能变化，并利用核磁（?）及计算机模拟等手段对识别现象进行进一步解析。结果表明，大多数主体与所考察的客体分子形成了1：1型的超分子配合物。偶氮类主体对对硝基苯胺有较好的识别选择性，结合常数达5000M^-1左右，单手性臂胆甾主体对D-氨基酸甲酯的识别优于L-氨基酸甲酯，选择性K_D／K_L最高达89。识别的推动力主要源于主客体之间的氢键、π-πstacking、van der Waals作用等非共价键力。同时，主体的刚柔度、手臂结构不同所造成的微环境效应、主客体在大小、形状及几何空间上的互补和匹配在识别和对映选择性过程中也起重要作用。更多还原

【Abstract】 The study on molecular recognition of artificial receptors is one of the frontiers in bioorganic chemistry. In this dissertation, the efforts were focused on design and synthesis of new types of chiral and achiral azoamide hosts,bowl-shaped steroid cholic acid methyl esters with one chiral arm under microwave irradiation and heteroaromatic molecular tweezers under microwave irradiation in solid state and their molecular recognition as well as enantioselective recognition. A series of useful and creative results have been obtained.Three new typical molecular clefts containing azo, heteroaromatic and cholest unit have been designed and synthesized. Among them the chiral azoamide hosts were designed and synthesized for the first time. The synthetic methods of the target compounds have been systematically investigated. A series of convenient and efficient reactions have been developed. Especially, during the preparation of heteroaromatic molecular clefts, we used microwave irradiation in solid state so that steps were shortened and yields were enhanced, and a new ecofrindly synthesis method was realized. All these cleft-type receptors possess different size of clefts, different recognition sites, different rigidity and flexibility and different chiral centers. Their structures were confirmed by IR, ’HNMR, MS and element analyses.Molecular recognition properties of the molecular clefts synthesized for neutral molecules and chiral molecules were examined by UV-visible spectra titration. The association constants (IgKa) and Gibbs free energy changes (- A GO) were determined. The 1HNMR spectra and computer-aided molecular modeling were used to elucidate further the recognition abilities. The results show that 1 : 1 inclusion complexes are formed for the most of molecular clefts with guests examined. The chiral molecular tweezers containing azo unit show excellent selective recognition ability forp-nitroaniline, and the association constants can attend to 5000 M-1. The steroid cholic acid methyl ester molecular clefts with one chiral arm are favorable for complexation with D-amino acid methyl esters. The enantioselectivities KD/KL of some hosts are more than 89. The drive forces of molecular recognition mainly come from non-covalent forces between host and guest , such as hydrogen bond , stacking, van der Waals interaction etc. At the same time, the rigidity and flexibility of receptors, micro-environmental effects of different cleft structures, the size/shape-matching relationship between host and guest also play crucial roles in the selective molecular binding process of molecular cleft.更多还原