【作者】 金伟伟；

【导师】 肖文精； 余正坤；

【作者基本信息】 华中师范大学 ， 有机化学， 2009， 硕士

【摘要】 近年来,利用过渡金属催化芳烃C-H键活化形成新C-C键在有机合成研究中受到了广泛的关注,是有机化学研究领域的热点之一。本论文研究了在无膦条件下,Rh（Ⅰ）催化酸酐作为偶联试剂的芳烃C-H键活化反应,主要研究内容如下:一、无膦条件下,Rh（Ⅰ）催化酸酐作为偶联试剂的芳烃C-H键活化反应研究论文研究了催化剂、碱、添加剂以及温度等因素对芳烃与酸酐的C-H活化反应的影响。在最优化的反应条件即:以2.5-5.0mol%[Rh（COD）C1]₂作为催化剂、碳酸钠作为碱、4A分子筛作为添加剂、邻二甲苯作为溶剂,在145℃下回流9-12h,最终以高达97%的收率得到了芳烃芳基化和烯基化的产物,产物具有高达99%的区域选择性/立体选择性。二、三组分竞争反应研究通过三组分竞争反应发现在反应体系中酸酐的反应活性要高于酰氯,进一步证明了在C-H活化反应中酸酐作为偶联试剂的可行性和优越性。三、反应机理研究综合我们的实验结果,并参考了相关研究的文献,我们提出了可能的催化反应机理:首先酸酐与Rh（Ⅰ）氧化加成形成芳酰基羧酸酯金属络合物[RCORh（Ⅲ）CI（OCOR）],然后该金属络合物脱羰基形成中间体8,中间体8与芳烃在碱的作用下通过邻位辅助的分子内C-H键活化形成络合物9,9还原消除得目标产物,同时释放出Rh（Ⅰ）物种进入下一个循环。所有反应产物都经核磁共振光谱、高分辨质谱进行结构表征和确证。更多还原

【Abstract】 Transition metal-catalyzed activation of aromatic C-H bonds followed by new C-C bond formation has been paid considerable attention in organic synthesis.In this thesis, efficient regioselective direct arylation and alkenylation of aromatic C-H bonds by Rh（Ⅰ） catalysis using aromatic carboxylic and cinnamic anhydrides as the coupling partners via decarbonylative C-H bond activation of arene or N-heteroaromatic substrates was investigated under phosphine-free conditions.Rh（Ⅰ）-catalyzed direct arylation and alkenylation of aromatic C-H bonds using anhydrides as the coupling partners under phosphine-free conditions were successfully realized.Under the optimal conditions,the corresponding arylation and alkenylation compounds were formed in isolated yields up to 97%with excellent regio- / stereoselectivities.Three-component competition reactions were carried out to explore the reactivity of anhydrides and chlorides under the typical conditions.The results have revealed that the present catalytic system is much more efficient than the Rh（Ⅰ）/aroyl chloride system for the same purpose.A possible reaction mechanism is proposed.An anhydride is oxidatively added to the Rh（Ⅰ） species to form an aroylcarboxylate metal complex[RCORh（Ⅲ）Cl（OCOR）] which undergoes decarbonylation to form Rh（Ⅲ）-arylcarboxylate intermediate.This intermediate reacts with arene to generate a C-H bond activation complex via intramolecular ortho-chelating assistance in the presence of Na₂CO₃ base.The desired product is then produced via the reductive elimination of C-H bond activation complex.All the target compounds were characterized by ¹H NMR,¹³C{¹H} NMR,and HRMS analyses.更多还原