Environmentally Benign Processes for Making Useful Fluorocarbons: Nickel- or Copper(I) Iodide-Catalyzed Reaction of Highly Fluorinated Epoxides with Halogens in the Absence of Solvent and Thermal Addition of CF<sub>2</sub>I<sub>2</sub> to Olefins
作者:Zhen-Yu Yang
DOI:10.1021/jo0354488
日期:2004.4.1
yields. The reaction probably involves an oxidative addition of fluorinated epoxides into metal surfaces to form an oxametallacycle, followed by rapid decomposition to difluorocarbene−metal surfaces, which alters the reactivity of the difluorocarbene carbon from electrophilic to nucleophilic. The increase of nucleophilicity of difluorocarbene facilitates the reaction with electrophilic halogens. CF2I2 reacted
高度氟化环氧化物与镍粉或CuI和在升高的温度下存在的卤素反应以提供dihalodifluoromethanes的有用和一般合成(CF 2 X 2)和氟酰基氟化物(R ˚F在无溶剂COF)。在185°C下,六氟环氧丙烷和卤素以68-90%的分离产率生成CF 2 X 2(X = I,Br),以及少量X(CF 2)n X(n = 2,3)。含卤素间化合物X(X = Cl,Br),CF 2 I 2,CF 2 XI和CF 2 X 2的混合物获得了。被全氟苯基,氟磺酰基和氯氟烷基取代的氟化环氧化物也与碘干净反应,以高收率得到CF 2 I 2和相应的氟化酰基氟。该反应可能涉及将氟化环氧化物氧化添加到金属表面以形成氧杂金属环,然后迅速分解为二氟卡宾-金属表面,从而将二氟卡宾碳的反应性从亲电性变为亲核性。二氟卡宾的亲核性的增加促进了与亲电子卤素的反应。CF 2我2与烯烃热反应得到1,3-二碘氟丙烷衍生物。氟