低共熔溶剂仿生催化氧化体系研究

Research on biomimetic catalytic system of eutectic solvent

氧化反应是自然界中最重要的反应之一,也是有机合成中的关键转化步骤.开发环境友好的、高活性、高选择性的催化剂,是实现氧化反应的有效途径.由于存在较高的活化势垒,在温和条件下用氧气直接进行氧化反应比较困难.低共熔溶剂作为一种新型的绿色溶剂,在化学反应过程中,可以同时作为萃取剂、反应介质和催化剂.若在功能化低共熔溶剂和氧气分子之间引入电子转移介质,电子经电子转移介质沿着低能量途径从低共熔溶剂转移到氧气分子,可规避直接氧化反应的高活化能,实现温和条件下氧气的活化和底物的催化氧化,我们称之为以氧气为氧化剂的低共熔溶剂仿生催化.除此以外,低共熔溶剂也可以通过模仿其他生物酶,如过氧化物酶等来构建以过氧化氢为氧化剂的仿生氧化体系.本文系统总结了近年来低共熔溶剂在仿生催化领域的研究进展,并对其在催化氧化中的应用进行了讨论,分析了低共熔溶剂在仿生催化领域的发展趋势,指出了未来亟需解决的重要问题.

The oxidation reaction is one of the most important reactions in nature and a key transformation step in organic synthesis. The development of environmentally friendly, highly active, and highly selective catalysts is an effective way to realize oxidation reactions. However, it is difficult to directly perform the oxidation reaction with dioxygen due to the oxygen-induced high activation barrier under mild conditions. As a new type of green solvents, deep eutectic solvents have received extensive attention from academia and industry. The functionalized eutectic solvent can be used as an extractant, reaction medium, and catalyst simultaneously in the chemical reaction process. When an electron transfer medium is introduced between the functionalized eutectic solvent and dioxygen, the electrons will be transferred from the eutectic solvent to the oxygen molecules through the electron transfer medium along the low-energy pathway. It will avoid the high activation energy of the direct oxidation reaction and realize the activation of oxygen and the catalytic oxidation of the substrate under mild conditions, which is called low eutectic solvent biomimetic catalysis.In addition, the deep eutectic solvents can also imitate other biological enzymes, such as peroxidase, to construct a biomimetic oxidation system with hydrogen peroxide as the oxidant. This review systematically summarizes the research progress of eutectic solvents in biomimetic catalysis in the past three years, discusses its application in catalytic oxidation, analyzes the development trend of eutectic solvents in the field of biomimetic catalysis, and points out the urgent problems needed to be solved in the future.