氮掺杂氧化石墨催化苄胺氧化

Catalytic oxidation of benzylamine over N-stimulated graphite oxide

酰胺类化合物是重要的化工原料和生物医药合成的中间体,但其制备大部分需要使用贵金属催化剂,因此,发展廉价金属乃至非金属催化剂具有重大意义.本文使用化学气相沉积法合成了氮掺杂的层状氧化石墨材料,并将其应用于苄胺氧化反应中,实现了液相中酰胺合成的非金属催化过程.在水相中可以活化氧气较高产率地生成亚胺化合物N-苄亚甲基苄胺,并且成功实现了在氨水反应介质中高转化率和选择性地生成苯甲酰胺.此外,对反应中的影响因素进行了逐一研究,并从多方面探究了该反应中氨水的作用以及反应最可能的历程,提出了一条经过包括亚胺在内的多个中间产物的反应路径.本工作对于研究碳氢键的活化过程以及拓宽碳催化领域进行了有益的尝试.

In this paper, we synthesized nitrogen-doped graphite oxide materials by the chemical vapor deposition method, and employed the cheap metal-free catalytic material to replace the noble metal catalysts that are currently used for the production of amide compounds. The metal-free catalytic reactions were performed in the liquid systems to synthesize benzamide by the oxidation of benzylamine. It is found that high selectivity and superior yield towards benzamide was achieved in the ammonia medium. In contrast, oxygen was activated in water to transform benzylamine to the imine compound. A variety of reaction parameters were investigated to study the reaction mechanisms as well as the role of ammonia. We conclude that the reaction process involves multiple elementary steps with the imine as the intermediate. Our work enriches the carbocatalysis knowledge and sheds lights on the C-H bond activation.