Copper‐Catalyzed Trifluoromethylation of Internal Olefinic CH Bonds: Efficient Routes to Trifluoromethylated Tetrasubstituted Olefins and N‐Heterocycles |
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| Authors: | Zhifeng Mao Fei Huang Dr Haifeng Yu Prof?Dr Jiping Chen Prof?Dr Zhengkun Yu Prof?Dr Zhaoqing Xu |
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| Affiliation: | 1. Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023 (China), Fax: (+86)?411‐8437‐9227;2. Department of Chemistry, Anshan Normal University, Anshan, Liaoning 114007 (China);3. State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Road, Shanghai 200032 (China);4. Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Lanzhou University, Lanzhou 730000 (China) |
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| Abstract: | The functionalization of internal olefins has been a challenging task in organic synthesis. Efficient CuII‐catalyzed trifluoromethylation of internal olefins, that is, α‐oxoketene dithioacetals, has been achieved by using Cu(OH)2 as a catalyst and TMSCF3 as a trifluoromethylating reagent. The push–pull effect from the polarized olefin substrates facilitates the internal olefinic C?H trifluoromethylation. Cyclic and acyclic dithioalkyl α‐oxoketene acetals were used as the substrates and various substituents were tolerated. The internal olefinic C?H bond cleavage was not involved in the rate‐determining step, and a mechanism that involves radicals is proposed based on a TEMPO‐quenching experiment of the trifluoromethylation reaction. Further derivatization of the resultant CF3 olefins led to multifunctionalized tetrasubstituted CF3 olefins and trifluoromethylated N‐heterocycles. |
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| Keywords: | C H activation copper olefins trifluoromethylation |
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