氨基修饰的β-环糊精催化三组分反应的研究

发布时间：2018-04-30 02:36

本文选题：超分子催化 + 三组分反应　；参考：《昆明理工大学》2016年硕士论文

【摘要】：超分子催化是最接近于天然酶的化学反应形式。主要是通过主体大分子与客体小分子间的相互作用来实现。环糊精作为第二代超分子主体,不仅可以用于分子识别和自组装,而且其可作为超分子催化剂催化化学反应。p-环糊精由于价廉易得而获得最多关注,但存在水溶性较差的缺点。而且由于其官能团单一,导致其催化性能和范围受到较大限制。对p-环糊精进行结构修饰是一种有效的改造手段,而使用氨基对其进行修饰,可望将超分子催化与胺催化相结合,从而有效增强其在有机合成中的应用。本论文一共设计并合成了6种不同长度氨基链修饰的p-环糊精催化剂(ACDs, a0-5),将其用于催化多组分反应。一方面,通过观察此类催化剂在反应中的催化效果,获取催化剂结构与反应效果之间的构效关系；另一方面,利用核磁共振、质谱和光谱滴定等手段研究其反应机理,为进一步的研究提供一定的理论基础。本论文完成的主要工作如下：一、合成了4种氨基侧链修饰的β-环糊精(a0-3),将其用于催化合成一系列四酮类化合物。该实验的主要内容包括：1、以苯甲醛和5,5-二甲基-1,3-环己二酮为底物进行催化剂筛选及反应条件优化。2、对反应底物进行筛选,底物涉及芳香醛、脂肪醛、醛类似物、二酮及其类似物。3、通过核磁(1H-NMR和2D-NMR), HR-MS和Job's曲线等手段对催化机理进行研究。4、通过催化剂循环使用次数及回收实验对催化剂效能进行评估。本文一共合成了30种四酮产物(产率58-97%),我们发现,随着氨基侧链的延长,催化效率越高。该方法绿色、高效、操作简单、适合的底物范围广泛。最重要的是催化剂在循环使用8次后,催化效率依然保持在90%以上。而且催化剂回收方法简单、绿色环保。二、本论文又合成了另外两种氨基侧链修饰的p-环糊精(a4-5),将一整系列的ACDs用于催化2-氨基-4H-苯并吡喃类化合物的合成。实验内容主要包括：1、以苯甲醛、丙二腈、间苯二酚为底物进行催化剂的筛选及反应条件优化。2、对底物进行筛选,不仅设计合成简单的2-氨基-4H-苯并吡喃类化合物,而且还设计合成了复杂的螺环化合物。3、通过核磁(1H-NMR和2D-NMR), HR-MS等手段对催化机理进行研究。实验中一共设计合成了32种化合物(10种新化合物),通过对催化剂的筛选我们发现,只有一定长度的氨基侧链能够使反应高效生成目标产物,首次发现该类催化剂能影响三组分反应产物的化学选择性。本文设计合成了一系列氨基修饰的β-环糊精催化剂,并对其在三组分反应中的催化作用进行研究。首次揭示这种胺类环糊精在多组分反应中产生化学选择性的深层次机理,可以为此类超分子主体/有机催化剂共同构建的超分子催化体系的设计提供新思路。
[Abstract]:Supramolecular catalysis is the closest form of chemical reaction to natural enzymes. It is mainly realized by the interaction between host macromolecule and guest small molecule. As the second generation supramolecular host, cyclodextrin not only can be used for molecular recognition and self-assembly, but also can be used as a supramolecular catalyst to catalyze the chemical reaction. Because of its single functional group, its catalytic performance and range are limited greatly. The modification of p-cyclodextrin structure is an effective means of modification, but it is expected to combine supramolecular catalysis with amine catalysis to effectively enhance its application in organic synthesis. In this paper, six kinds of p-cyclodextrin catalysts (ACD _ s, a0-5) modified with different lengths of amino chains were designed and synthesized, which were used to catalyze multicomponent reactions. On the one hand, the structure-activity relationship between the structure of the catalyst and the reaction effect was obtained by observing the catalytic effect of the catalyst in the reaction; on the other hand, the reaction mechanism was studied by means of nuclear magnetic resonance, mass spectrometry and spectral titration. To provide a theoretical basis for further research. The main work of this thesis is as follows: firstly, four kinds of 尾 -cyclodextrin modified 尾 -cyclodextrin (尾 -cyclodextrin) (尾 -cyclodextrin) were synthesized and used to catalyze the synthesis of a series of tetraketones. The main contents of the experiment include: 1, using benzaldehyde and 5-dimethyl-1-dimethyl-3-cyclohexanedione as the substrates to screen the catalyst and optimize the reaction conditions. The substrate includes aromatic aldehydes, aliphatic aldehydes and aldehydes analogues. The catalytic mechanism was studied by NMR, 2D-NMR-NMR, HR-MS and Job's curves. The catalytic efficiency was evaluated by the recycle times of the catalyst and the recovery experiment. A total of 30 tetraketones were synthesized in this paper. We found that the higher the catalytic efficiency is with the prolongation of the amino side chain. The method is green, efficient, easy to operate and suitable for a wide range of substrates. The most important thing is that the catalytic efficiency remains above 90% after 8 cycles. And the catalyst recovery method is simple, green environmental protection. Secondly, two other amino side chain modified pcyclodextrin 4-5N were synthesized in this paper. A series of ACDs was used to catalyze the synthesis of 2-amino-4H-benzopyran compounds. The main contents of the experiment include: 1, screening of catalysts with benzaldehyde, malonitrile and resorcinol as substrates, optimization of reaction conditions, screening of substrates, design and synthesis of simple 2-amino-4H-benzopyran compounds. The complex snail compound. 3 was designed and synthesized, and the catalytic mechanism was studied by NMR, 2D-NMRO, HR-MS and so on. A total of 32 compounds and 10 new compounds were designed and synthesized in the experiment. By screening the catalyst, we found that only a certain length of amino side chain could efficiently produce the target product. It was found for the first time that this kind of catalyst could affect the chemical selectivity of the reaction products. A series of amino-modified 尾 -cyclodextrin catalysts were designed and synthesized in this paper. It is the first time to reveal the deep mechanism of the chemical selectivity of this amine cyclodextrin in multicomponent reactions, which can provide a new idea for the design of supramolecular catalytic system constructed by the supramolecular host / organic catalyst.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O621.251

【相似文献】