- Synergistic lewis acid and photoredox-catalyzed trifluoromethylative difunctionalization of alkenes with selenium ylide-based trifluoromethylating reagent
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Trifluoromethylative difunctionalization of alkenes with a variety of nucleophiles including amine, azide, alcohol, water, and electron-rich arenes using reagent 1 as trifluoromethyl radical source in the presence of a synergistic catalyst including a Lewis acid scandium(III) trifluoromethanesulfonate (Sc(OTf)3) and a photoredox catalyst [fac-Ir(ppy)3] was described. Mechanistic studies showed that the role of Sc(OTf)3 in the reaction is to activate reagent 1 via Lewis acid?Lewis base interaction to form complex [Sc(OTf)3?3(1)], which was fully characterized by nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry, and elemental analysis. Cyclic voltammetry (CV) experiments and density functional theory (DFT) calculation showed that the reduction potential of complex [Sc(OTf)3?3(1)] is much higher than that of reagent 1, thus suggesting complex [Sc(OTf)3?3(1)] is much easier to accept electron through single-electron-transfer (SET) process, and consequently, much easier to generate trifluoromethyl radical.
- Shen, Qilong,Ge, Hangming,Wu, Botao,Liu, Yafei,Wang, Haoyang
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p. 12414 - 12424
(2020/11/10)
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- Cobalt-Tertiary-Amine-Mediated Hydroxytrifluoromethylation of Alkenes with CF3Br and Atmospheric Oxygen
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The mild and efficient hydroxytrifluoromethylation of alkenes with bromotrifluoromethane (CF3Br) and atmospheric oxygen mediated by cobalt-tertiary amine is described. This reaction proceeds with broad substrate scope and good functional group compatibility. Mechanistic studies indicate that the reaction proceeds through a radical pathway, which is enabled by combination of the previously unexplored highly efficient N-isopropyl-N,2-dimethylpropan-2-amine with Co(II) for the single electron reduction of CF3Br to CF3 radical.
- Li, Qiankun,Fan, Wu,Peng, Deqian,Meng, Bingyin,Wang, Shaohan,Huang, Rui,Liu, Shihao,Li, Suhua
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p. 4012 - 4018
(2020/05/05)
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- Method for preparing hydroxyl and trifluoromethyl substituted compounds through reaction of olefin and trifluo-romethyl bromide
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The invention discloses a method for preparing hydroxyl and trifluoromethyl substituted compounds through olefin addition reaction. According to the method, a compound containing carbon-carbon doublebonds and trifluo-romethyl bromide are taken as raw materials, a metal salt-tertiary amine system is taken as a catalyst, air is taken as an oxidizing agent, carbon-carbon double bonds can be subjected to addition reaction, and compounds with hydroxyl substitution and trifluoromethyl substitution at the same time are prepared; wherein the metal salt is one or more selected from a cobalt salt, a silver salt, a bismuth salt, a nickel salt, an iron salt or a copper salt; the tertiary amine is N-isopropyl-N-methyl-tert-butylamine or N, N-diisopropylethylamine. According to the method, the metal salt-tertiary amine system is taken as a catalyst for the first time, hydroxyl substitution and trifluoromethyl substitution of olefins are realized, one-step reaction is enough, reaction process conditions are mild, reaction raw materials are cheap and easily available, cost is low, reaction substrates have strong applicability, and can participate in the reaction as long as carbon-carbon double bonds exist in the structures, and are not influenced by substituent groups on double bond carbon atoms, and the product yield is high.
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Paragraph 0050-0058; 0197-0204
(2020/01/14)
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- Three-component oxytrifluoromethylation of alkenes: Highly efficient and regioselective difunctionalization of C=C bonds mediated by photoredox catalysts
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Here comes the sun: A facile vicinal difunctionalization of alkenes, oxytrifluoromethylation, was established by visible-light-driven photoredox catalysis. Judicious choice of the CF3 source is key. Nucleophiles such as water, alcohols, and carboxylic acids can be used in this highly efficient (2-4 h) and regioselective (100 %) transformation using light-emitting diode (LED) lamps and natural sunlight. SET=single-electron transfer. Copyright
- Yasu, Yusuke,Koike, Takashi,Akita, Munetaka
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supporting information
p. 9567 - 9571
(2012/11/07)
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