活性炭固载Cu(II)可见光催化氢胺化反应研究

氢胺化反应是以100%原子经济性将氮–氢键加成到碳–碳不饱和键形成碳–氮键的合成方法，广泛用于合成高附加值含氮医药化合物及精细化学品，因而备受化学家们的关注。然而，氢胺化反应同时具有活化能高（跨过能量势垒需催化剂及高温）以及熵减（高温不利于反应进行）的特点，这一矛盾致使反应效率不能仅仅依靠提高温度获得提升。催化氢胺化反应常用的过渡金属配合物催化剂还存在合成复杂、反应后分离困难等问题。基于申请人最近的研究结果，为解决目前存在的这些基本问题，本项目首次提出设计合成廉价、易于从反应体系分离的高比表面积活性炭固载的Cu(II)光催化剂，利用反应物胺与Cu(II)形成配合物吸收可见光从而在低温下活化氮–氢键，实现高效催化氢胺化反应的思路。本项目的研究不仅对含氮化合物的绿色催化合成具有重要意义，对深入研究金属离子在活性炭上吸附机制也具有积极意义。

The catalytic hydroamination reaction is a significant reaction that involves the direct addition of an N-H bond to an unsaturated C-C bond with a 100% atom economy. It is widely used for the production of high-value nitrogen-containing pharmaceutical intermediates and numerous important fine chemicals. However, the contradiction between high activation energy (high temperature is required to surmount the energy barrier) and entropy reduction (high temperature is unfavorable for the reaction) of hydroamination reaction determines that the reaction rate may not increase with the elevated temperature. In addition, the transition metal complex catalysts also suffered from the problems such as high cost and separation difficulty after reaction. Based on our preliminary study, we propose a novel design to prepare the photocatalyst by immobilizing Cu(II) on high specific surface area activated carbon for hydroamination reaction to solve these problems. The surface complexes between Cu(II) and reactant species (amines) play a key role to harvest visible light and thus make it possible to activate the N-H bond at low temperature and achieve hydroamination of alkynes/alkenes. The new type of photocatalyst is also cheap and easy for separation for reuse. The in-depth study of this proposed project will shed light on the green synthesis of nitrogen-containing compounds, and will also provide knowledge for the adsorption of metal ions on activated carbon.