基于钯催化亲电硼氢键活化的o-碳硼烷区域选择性单芳基化研究

具有二十面体结构和三维芳香性的o-碳硼烷以其独特的光电、生化特性，在材料化学、配位化学以及药物化学等领域具有重要的应用前景。由于o-碳硼烷含有10个不完全等价的B-H键，且相互之间反应活性差异甚微，使得其区域选择性单官能化成为了一个非常有挑战性的课题。基于o-碳硼烷与芳香烃在反应特性上的相似性，本课题根据o-碳硼烷的结构特点、电子特性以及芳烃C-H键活化的理论基础，拟利用钯催化亲电B-H键的活化策略对反应活性相近的B-H(9,12)/B-H(8,10)键进行区域选择性活化，并利用反应过渡态的位阻效应控制B-H(9,12)/B-H(8,10)键的单芳基化；探索B-H键的活化方式和新的成键模式，揭示B-H键的反应特性及活化机理，学术意义显著。利用B-H活化策略实现C-B键的区域选择性构建，有效避免了传统方法中利用预官能化的B-I键与格氏试剂偶联的不足，具有重要的应用价值。

In recent years, o-carborane, featured with icosahedron and three-dimensional aromaticity, has received much attention due to its unique photoelectric and biochemistry characteristic, and has important application perspective in materials chemistry, coordination chemistry and pharmaceutical chemistry etc.. Due to the 10 B-H bonds of o-carborane are not fully equal and only have slightly difference in reactivity, thus led the mono-functionalization of B-H bond with regioselectivity to be a challenge subject. Based on the similar reactivity of o-carborane with arenes, the three-dimensional aromaticity and structure characteristic of o-carborane, and the theory of C-H activation of arenes, we intend to explore the regioselective activation of B-H(9,12)/B-H(8,10) bonds via palladium catalyzed electrophilic B-H activation, and realize their regioselective mono-arylation by steric effect of transition state. Through our effects, we would disclose the activation and novel bonding mode, reaction behavior and activation mechanism of B-H bond. It has potential application values by using the method of B-H bond activation to construct C-B bond to avoid the drawbacks of coupling of B-I bond with Grignard reagents.