芳烃和烷烃在金属表面的C−H键活化交叉偶联反应及其机理研究

“碳基能源的转化与高效利用”的关键问题之一是如何实现芳烃和烷烃在表界面的选择性活化和定向转化，而C-H键的选择性活化及官能化反应则是其中的核心内容。不同于已有的“底物控制法”策略，本项目拟创新性地采用“导向基团法”和表面催化剂调控相结合的策略，在芳烃和烷烃前驱体分子中引入合适的导向基团，并在相对惰性的金属基底上沉积高催化活性的过渡金属作为催化剂；通过导向基团的配位反应引导金属催化剂选择性地活化特定位置的C−H键，同时使C−H键断裂的反应能垒得到显著降低，在较低温度下实现金属表面的芳烃和烷烃的C−H键高选择性活化；再通过与各种官能化试剂反应，得到交叉偶联的官能化产物。另外，还将使用扫描隧道显微镜、飞行时间-二次离子质谱和别的表面分析手段，结合密度泛函理论计算，阐明导向基团和表面催化剂对于C−H键活化反应的调控机制及交叉偶联反应的机理。

One of the most charming and challenging topics in organic chemistry and chemical industry is the selective activation and functionalization of C-H bonds of arenes and alkanes on surfaces, which play a key role in the energy science. Different from the substance control strategy, this project will utilize the strategy combined directing group and surface catalysis, to introduce the suitable directing groups into the arene and alkane precusors and dose highly catalytic transition-metal catalysts on metal surfaces. Through the coordination of directing group with the metal catalyst, specific C-H bond could be activated and the reaction barrier to break the C-H bond could decrease dramatically, leading to the high selectivity and low reaction temperature of C-H bond activation of arenes and alkanes. The further reactions with various functionalization reagents will afford the cross-coupling products. Moreover, through the combination of scanning tunneling microscope, Time-of-Flight secondary ion mass spectrometry, density functional theory calculations and other surface analysis tools, we are able to demonstrate the reaction pathway and the reaction mechanism of the directing group-controlled C-H bond activation and the subsequent cross-coupling reactions on surfaces.