Cathodic C–H Trifluoromethylation of Arenes and Heteroarenes Enabled by an in Situ-Generated Triflyltriethylammonium Complex
作者:Wolfgang Jud、Snjezana Maljuric、C. Oliver Kappe、David Cantillo
DOI:10.1021/acs.orglett.9b02948
日期:2019.10.4
While several trifluoromethylation reactions involving the electrochemical generation of CF3 radicals via anodic oxidation have been reported, the alternative cathodic, reductive radical generation has remained elusive. Herein, the first cathodic trifluoromethylation of arenes and heteroarenes is reported. The method is based on the electrochemical reduction of an unstable triflyltriethylammonium complex
Solid‐State Radical C−H Trifluoromethylation Reactions Using Ball Milling and Piezoelectric Materials
作者:Yadong Pang、Joo Won Lee、Koji Kubota、Hajime Ito
DOI:10.1002/anie.202009844
日期:2020.12.7
The application of piezoelectricity for the generation of trifluoromethyl (CF3) radicals is reported together with the development of a method for the mechanochemical C−H trifluoromethylation of aromatic compounds. As compared to conventional solution‐based approaches, this mechanoredox C−H trifluoromethylation enables cleaner and more sustainable access to a wide range of trifluoromethylated N‐heterocycles
Nickel(IV)-Catalyzed C–H Trifluoromethylation of (Hetero)arenes
作者:Elizabeth A. Meucci、Shay N. Nguyen、Nicole M. Camasso、Eugene Chong、Alireza Ariafard、Allan J. Canty、Melanie S. Sanford
DOI:10.1021/jacs.9b06383
日期:2019.8.14
This Article describes the development of a stable NiIV complex that mediates C(sp2)-H trifluoromethylation reactions. This reactivity is first demonstrated stoichiometrically and then successfully translated to a NiIV-catalyzed C-Htrifluoromethylation of electron-rich arene and heteroarene substrates. Both experimental and computational mechanistic studies support a radical chain pathway involving
Electrophotocatalytic Undirected C−H Trifluoromethylations of (Het)Arenes
作者:Youai Qiu、Alexej Scheremetjew、Lars H. Finger、Lutz Ackermann
DOI:10.1002/chem.201905774
日期:2020.3.12
enabled arene C-H trifluoromethylation with the Langlois reagent CF3SO2Na under mild reaction conditions. The merger of electrosynthesis and photoredox catalysis provided a chemical oxidant-free approach for the generation of the CF3 radical. The electrophotochemistry was carried out in an operationally simple manner, setting the stage for challenging C-H trifluoromethylations of unactivated arenes
电化学使芳烃 CH 在温和的反应条件下用郎格鲁瓦试剂 CF3 SO2 Na 发生三氟甲基化。电合成和光氧化还原催化的结合为CF3自由基的产生提供了一种无化学氧化剂的方法。电化学光化学以操作简单的方式进行,为挑战未活化芳烃和杂芳烃的CH三氟甲基化奠定了基础。电化学流形的鲁棒性反映在广泛的范围内,包括富电子和缺电子的苯,以及天然存在的杂芳烃。电光化学CH三氟甲基化进一步通过配备有用于在线流式NMR光谱的操作中监控单元的模块化电流动池在流动中实现,为单电子转移过程提供支持。
Metal- and Oxidant-Free Photoinduced Aromatic Trifluoromethylation Performed in Aerated Gel Media: Determining the Effects on Yield and Selectivity
In this work we have investigated the potential benefits of using supramolecular gel networks as reaction media to carry out air-sensitive metal-free light-induced trifluoromethylation of six-membered (hetero)arenes under aerobic conditions. This reaction was performed at room temperature (RT) using sodium triflinate (CF₃SO₂Na, Langlois' reagent) as a source of radicals and diacetyl as electron donor
在这项工作中,我们研究了使用超分子凝胶网络作为反应介质在有氧条件下进行六元(杂)芳烃的空气敏感无金属光诱导三氟甲基化的潜在好处。该反应在室温(RT)下进行,使用三氟甲磺酸钠(CF 3 SO 2 Na,朗格卢瓦试剂)作为自由基源,二乙酰基作为电子供体。评估了凝胶介质中的限制、反应物浓度和光源类型对产率和产物分布的影响,并与均匀溶液中获得的结果进行比较。本研究使用了四种不同的低分子量 (LMW) 胶凝剂。结果证实了凝胶介质对外部氧气引起的反应猝灭的阻断作用,以及对动力学和选择性的一定控制。