铑催化C-H活化反应机理的理论研究

发布时间：2018-03-06 08:43

本文选题：铑催化　切入点：密度泛函理论　出处：《温州大学》2016年硕士论文　论文类型：学位论文

【摘要】：铑催化C-H活化反应是当前有机化学研究的热点,该类反应是把不活泼的C-H键转变成C-C键、C-X键的有效途径。本论文运用密度泛函理论(DFT)对铑催化含有内部氧化剂的苯甲酰胺衍生物C-H活化反应机理进行了理论研究。通过对各种反应路径能量的比较,确定了反应的具体历程,同时对实验中的现象进行了解释,本论文研究结果对今后的实验设计和相关理论研究具有重要的理论指导意义。本论文包括以下两方面的研究内容:(1)铑催化苯甲酰胺衍生物与亚甲基环丙烷的C-H活化/环化反应的机理研究。通过DFT计算首先研究了N-叔戊酰氧基苯甲酰胺与亚甲基环丙烷(MCP)反应的各种反应路径,计算结果发现,当芳基取代基为苯基时,反应发生OPiv迁移的过程;当芳基取代基为2-呋喃基时,反应发生β-C消除的过程;但两种反应过程均需形成Rh(V)-乃春中间体;当芳基取代基为2-噻吩基时,以上两种反应过程均可发生。然后对N-甲氧基苯甲酰胺与亚甲基环丙烷(MCP)的反应机理进行了理论计算研究,通过计算解释说明两者无反应发生的原因。(2)铑催化苯甲酰胺衍生物与环丙烯的C-H活化/环化反应的机理研究。通过DFT计算研究了Wang等人发现的由底物调控反应化学选择性的反应机理:反应通过C-H活化过程、烯烃插入形成七元苯并铑杂环的中间体后,当底物为N-叔戊酰氧基苯甲酰胺时,发现内部氧化剂N-O键断裂较β-C消除更容易,最终生成三环产物;当底物为乙酰苯胺时,发现β-C消除较内部氧化剂N-O键断裂更容易,最终生成取代的2H-吡喃产物。
[Abstract]:Rhodium-catalyzed C-H activation is a hot topic in organic chemistry. This kind of reaction is an effective way to transform the inert C-H bond into C-C bond C-X bond. In this paper, the mechanism of rhodium catalyzed activation of benzoamide derivative C-H with internal oxidant was studied by using density functional theory (DFT). By comparing the energy of various reaction pathways, The specific course of the reaction is determined, and the phenomena in the experiment are explained. The results of this thesis have important theoretical significance for future experimental design and related theoretical research. This thesis includes two aspects: 1) Rhodium catalyzed C-H activity of benzamide derivatives and methylene cyclopropane. The mechanism of cyclization reaction was studied by DFT calculation. Firstly, various reaction paths of N-tert-glutaryl benzoamide with methylene cyclopropane were studied. The results show that the process of OPiv migration occurs when the aryl substituents are phenyl, the 尾 -C elimination process occurs when the aryl substituents are 2-furyl, but both reaction processes need to form the intermediate RhVAV. When the aryl substituted group is 2-thiophene group, the above two reactions can occur. The mechanism of the reaction between N-methoxy benzoamide and methylene cyclopropane MCPis studied theoretically. The mechanism of C-H activation / cyclization of benzamide derivatives with cyclopropene catalyzed by rhodium was investigated by means of DFT calculations. The substrate-regulated reactions discovered by Wang et al were studied by DFT calculations. Selective reaction mechanism: reaction through C-H activation, After the alkenes were inserted into the intermediates of the 7-member benzo rhodium heterocycles, when the substrate was N-tert-glutaryl benzoamide, it was found that the N-O bond of the internal oxidant was easier to be destroyed than 尾 -C, and the tricyclic product was formed when the substrate was acetanilide. It is found that 尾 -C can eliminate the breakage of N-O bond more easily than the internal oxidant N-O bond, and finally produce the substituted 2H-pyran product.
【学位授予单位】：温州大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O621.251

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