摘要/Abstract
有机氟硅化合物是元素有机化学中最重要的高端产品种类之一，极具研究价值.开发了含二氟乙醇农药的新工艺技术，发展了一种条件温和和高效的铜催化二氟乙醇芳基醚化反应，通过大量的配体筛选和条件优化，建立了二氟乙醇和芳基溴或芳基碘的C—O偶联反应，简易合成出各种芳基取代的二氟乙基芳基醚.该反应以CuI为催化剂，在8-羟基喹啉和叔丁醇钾存在下顺利进行，具有广泛的底物适用性.ESI-MS分析证明，该催化过程可能存在三价铜催化机制，密度泛函理论（DFT）计算进一步表明该反应机理可能涉及三价铜的氧化加成、亲核取代及还原消除过程.
关键词: 乌尔曼反应, 铜催化, 含氟化合物, DFT计算, 8-羟基喹啉
Both organofluorine and organosilicon compounds are one of the most important types of high-tech product in elementorganic chemistry, and have been received much attetions in the past decades. Considering the imporatance of difluoroethanol moeity in pesticides, the development of a mild and efficient copper-catalyzed arylated etherification reaction of difluoroethanol is highly desirable. Herein, a mild and efficient method for the preparation of difluoroethyl aryl ethers was developed by the copper-catalyzed Ullmann-type arylated etherification reaction of aryl bromides or iodides with 2,2-difluoroethanol. This reaction proceeds smoothly in the presence of CuI and 8-hydroxyquinoline/t-BuOK, and has a broad substrate scope. ESI-MS analysis supported the existence of LCu(Ⅲ)Ar(OR) species during this catalytic reaction. Further density functional theory (DFT) calculations suggest a proposed mechanism of arylated etherification reaction involving oxidative addition, followed by nucleophile substitution and reductive elimination would be rational.
Key words: Ullmann reaction, Cu-catalyzed, fluorinated compound, DFT calculation, 8-hydroxyquinoline
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