- Electrochemical Synthesis of Fluorinated Ketones from Enol Acetates and Sodium Perfluoroalkyl Sulfinates
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The electrochemical synthesis of fluorinated ketones from enol acetates and RfSO2Na in an undivided cell under constant current conditions was developed. The electrosynthesis proceeded via perfluoroalkyl radical generation from sodium perfluoroalkyl sulfinate followed by addition to the enol acetate and transformation of the resulting C radical to a fluorinated ketone. The method is applicable to a wide range of enol acetates and results in the desired products in yields of 20 to 85%.
- Vil’, Vera A.,Merkulova, Valentina M.,Ilovaisky, Alexey I.,Paveliev, Stanislav A.,Nikishin, Gennady I.,Terent’ev, Alexander O.
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supporting information
p. 5107 - 5112
(2021/06/30)
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- Direct C(sp3)?H Trifluoromethylation of Unactivated Alkanes Enabled by Multifunctional Trifluoromethyl Copper Complexes
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A mild and operationally simple C(sp3)?H trifluoromethylation method was developed for unactivated alkanes by utilizing a bench-stable CuIII complex, bpyCu(CF3)3, as the initiator of the visible-light photoinduced reaction, the source of a trifluoromethyl radical as a hydrogen atom transfer reagent, and the source of a trifluoromethyl anion for functionalization. The reaction was initiated by the generation of reactive electrophilic carbon-centered CF3 radical through photoinduced homolytic cleavage of bpyCu(CF3)3, followed by hydrogen abstraction from an unactivated C(sp3)?H bond. Comprehensive mechanistic investigations based on a combination of experimental and computational methods suggested that C?CF3 bond formation was enabled by radical–polar crossover and ionic coupling between the resulting carbocation intermediate and the anionic CF3 source. The methylene-selective reaction can be applied to the direct, late-stage trifluoromethylation of natural products and bioactive molecules.
- Choi, Geunho,Lee, Geun Seok,Park, Beomsoon,Kim, Dongwook,Hong, Soon Hyeok
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supporting information
p. 5467 - 5474
(2021/01/20)
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- Radical Desulfur-Fragmentation and Reconstruction of Enol Triflates: Facile Access to α-Trifluoromethyl Ketones
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We report an efficient oxidative radical desulfur-fragmentation and reconstruction of enol triflates for the synthesis of α-CF3ketones. Preliminary mechanistic studies disclosed that oxidative fragmentation to release a CF3radical fr
- Su, Xiaolong,Huang, Honggui,Yuan, Yaofeng,Li, Yi
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p. 1338 - 1341
(2017/01/24)
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- Dialkylzinc-aceelerated α-trifluoromethylation of carbonyl compounds catalyzed by late-transition-metal complexes
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Trifiuoromethylation of ketone silyl enol ethers is found to be significantly accelerated by late-transition-metal catalysts and dialkylzincs to give α-trifluoromethyl ketones in good yields. Addition of dialkylzinc is the key to the high yielding α-trifl
- Tomita, Yuichi,Itoh, Yoshimitsu,Mikami, Koichi
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scheme or table
p. 1080 - 1081
(2009/12/03)
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- Zincate-type enolate for radical α-trifluoromethylation
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Ketone zincate-type enolates can be applied to radical trifluoromethylation for the general synthesis of α-CF3-ketones, cyclopentanones in particular. The addition of diethylzinc to lithium enolates is the key in the preparation of the zincate-
- Tomita, Yuichi,Ichikawa, Yoshiyuki,Itoh, Yoshimitsu,Kawada, Kosuke,Mikami, Koichi
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p. 8922 - 8925
(2008/03/14)
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- Radical trifluoromethylation of ketone silyl enol ethers by activation with dialkylzinc
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(Chemical Equation Presented) The radical trifluoromethylation of ketone silyl enol ethers gave α-CF3 ketones in good yields with wide scope of the ketonic substrates including acyclic ketones and cyclopentanone. The use of dialkylzinc to activ
- Mikami, Koichi,Tomita, Yuichi,Ichikawa, Yoshiyuki,Amikura, Kazutoshi,Itoh, Yoshimitsu
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p. 4671 - 4673
(2007/10/03)
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- Radical trifluoromethylation of ketone Li enolates
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It has generally been believed that highly basic Li enolates cannot be applied as substrates for radical trifluoromethylation due to defluorination of the α-CF3 product. However, Li enolates can be in fact employed for radical trifluoromethylat
- Itoh, Yoshimitsu,Mikami, Koichi
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p. 7199 - 7203
(2007/10/03)
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- Radical trifluoromethylation of Ti ate enolate: possible intervention of transformation of Ti(IV) to Ti(III) for radical termination
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The radical trifluoromethylation of ketone Ti ate enolates gave α-CF3 ketones in good yields. The use of excess amount of LDA and Ti(OiPr)4 in the preparation of Ti ate enolates is the key to the efficient radical trifluor
- Itoh, Yoshimitsu,Mikami, Koichi
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p. 539 - 544
(2008/03/14)
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- Facile radical trifluoromethylation of lithium enolates
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(Chemical Equation Presented) Highly basic lithium enolates are shown to be applicable to radical trifluoromethylation. The reaction is extremely fast, and the minimum reaction time is ~1 s.
- Itoh, Yoshimitsu,Mikami, Koichi
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p. 4883 - 4885
(2007/10/03)
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- Bi(CF3)3/Cu(OCOCH3)2 - A new system for the synthesis of 2-trifluoromethylcycloalkan-1-ones, trifluoromethylanilines and phenyl(trifluoromethyl)sulfane
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Bi(CF3)3 reacts in the presence of equimolar amounts of Cu(OCOCH3)2 and 1-morpholinocyclopentene to give 1-morpholino-2-trifluoromethylcyclopentene in 83% yield. This compound as well as intermediately formed 1-morpholino-2-trifluoromethylcyclohexene can easily be converted into the corresponding cycloketones (78 and 41% yield) using the Swarts procedure. In absence of a copper(II) source, no reactions were observed. The reaction of the system Bi(CF3)3/Cu(OCOCH3)2 with N,N-diethylaniline gave an 1.7: 1 isomer mixture of 2-trifluoromethyl and 4-trifluormethyl-N,N-diethylanilines in 48% yield. With tetrabutylammonium thiophenolate, mixtures of phenyl(trifluoromethyl)sulfane and diphenyldisulfane were obtained. Mechanisms are discussed.
- Kirij,Pasenok,Yagupolskii,Tyrra,Naumann
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p. 217 - 221
(2007/10/03)
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- Photoinduced Electron-transfer Reaction of Difluorodiiodomethane with Azaaromatic Compounds and Enamines
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Irradiation of difluorodiiodomethane 1 with pyrroles, indole and imidazoles in dimethylformamide gives the corresponding trifluoromethylated products, whereas irradiation with enamines results in 2-trifluoromethyl ketones.A photoinduced electron-transfer mechanism is proposed.
- Chen, Qing-Yun,Li, Zhan-Ting
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p. 645 - 648
(2007/10/02)
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- Photochemistry of 2-(Perfluoroalkyl)cycloalkanones
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In an earlier study we had compared the photochemical behaviour of 2-trifluoromethylcyclohexanone (1a) to that of the non fluorinated parent ketone 2-methylcyclohexanone.Substitution of the methyl group on C(2) by a CF3-group strongly enhances bimolecular reactions such as reductionproduct formation in 2-propanol or oxetane formation in the presence of alkenes.We now report preliminary results on monomolecular photochemical reactions of several 2-(perfluoroalkyl)cycloalkanones.
- Semisch, Christoph,Margaretha, Paul
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p. 471 - 475
(2007/10/02)
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