X-H键活化和偶联催化反应机理的理论研究

It has been long interest and effor for scientists to study the X-H activation, in which the C-H activation reactions are becoming hot topic recently，since this method has been applied to synthesis new long-chain compounds. In order to understand the reaction mechanisms, theoretical study is one of effective methods. In this project, DFT has been employed to locate the stationary points along the reaction paths, and the energy and free energy profiles could be obtained as well, and then the most probable reaction mechanism could be rationazied. It is worth to study not only the subsititut, ligand and solvent effects, but also the role of oxidant,which will be benefit to the experimental study from the complete theoretical studies.

X-H键的活化一直是化学工作者努力的方向，特别是C-H键的活化是近年来的热们课题。通过这种活化可以增长碳链的长度，可以合成一些有用的化合物。为了更好地理解这种反应的反应机理，理论研究是一种行之有效的手段。本项目主要采用密度泛函方法来优化反应过程中各驻点的几何构型，得到能量和自由能的势能剖面，这样可以合理地解释反应过程的最佳反应通道。在研究中除考虑取代基、配体效应、溶剂效应外，我们还需要考虑氧化剂作用，这样可以全面考察各种实验条件，为指导实验研究提供一种理论支持。

经过4年的努力，针对该基金项目，我们在5个方面有了进展，即Pd催化X-H活化反应机理；Rh催化环化反应机理；Cu催化C-H活化反应机理；稀土Th参与的一些反应机理；溶液平动熵的建立和在催化反应的应用。提出了一些新的见解，特别是总结了Pd催化中引导基团的作用以及引导基团的强弱对反应机理的影响等，这对于指导实验研究有一定的理论意义。