- Circumventing Intrinsic Metal Reactivity: Radical Generation with Redox-Active Ligands
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Nickel complexes have gained sustained attention as efficient catalysts in cross-coupling reactions and co-catalysts in dual systems due to their ability to react with radical species. Central to this reactivity is nickel's propensity to shuttle through several accessible redox states from Ni0 to NiIV. Here, we report the catalytic generation of trifluoromethyl radicals from a nickel complex bearing redox-active iminosemiquinone ligands. This unprecedented reactivity is enabled through ligand-based oxidation performing electron transfer to an electrophilic CF3+ source while the nickel oxidation state is preserved. Additionally, extension of this reactivity to a copper complex bearing a single redox equivalent is reported, thus providing a unified reactivity scheme. These results open new pathways in radical chemistry with redox-active ligands.
- Jacquet, Jérémy,Cheaib, Khaled,Ren, Yufeng,Vezin, Hervé,Orio, Maylis,Blanchard, Sébastien,Fensterbank, Louis,Desage-El Murr, Marine
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Read Online
- Multicomponent Cascade Synthesis of Trifluoroethyl Isoquinolines from Alkynes and Vinyl Azides
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A multicomponent cascade reaction is described that provides concise access to the trifluoroethyl isoquinolines using a Rh(III)-Cu(II) bimetallic system and readily available Togni's reagent. The system tolerates various vinyl azides and internal alkynes. Experimental results suggest that Togni's reagent might act as a CF3 radical supplier.
- Liu, Kai,Chen, Shuang,Li, Xing Guang,Liu, Pei Nian
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Read Online
- Rhodium-catalyzed α-fluoroalkylation reaction of ketones using silyl enol ethers
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The treatment of silyl enol ethers with fluoroalkyl halides (Rf-X) in the presence of RhCl(PPh3)3 gave α-fluoroalkylated ketones. It seems that a rhodium complex derived from the silyl enol ether and RhCl(PPh3)
- Sato, Kazuyuki,Higashinagata, Makoto,Yuki, Takashi,Tarui, Atsushi,Omote, Masaaki,Kumadaki, Itsumaro,Ando, Akira
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Read Online
- Synthesis method of alpha or beta-substituted aromatic ketone
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The invention discloses a synthesis method of alpha-or beta-substituted aromatic ketone. The method comprises the following steps: under the condition of inert gas, reacting alpha-oxo-aryl ethanone compounds, B2pin2, PDI-CoCl2 and MBHEt3 in an organic solvent at room temperature, then adding a compound 2, and continuously reacting to obtain a compound 3, wherein in the MBHEt3, M is an alkali metal; the compound 2 is selected from the group consisting of deuterated methanol, Selectfluoro, a TogniII reagent or R2CHO; R2 is an aromatic substituent or alkyl; the organic solvent is an aprotic organic solvent. According to the method, the alpha-oxo aryl ethanone is used as a raw material, a cheap and stable boron reagent and an efficient cobalt catalyst which is cheap and easy to obtain are used, an activating reagent MBHEt3 is added to generate an enol boron ether intermediate, then the enol boron ether intermediate and different electrophilic reagents are synthesized into alpha-or beta-substituted aromatic ketone, the reaction is carried out at normal temperature, and the operation is convenient.
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Paragraph 0022-0027; 0076-0080
(2021/05/01)
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- 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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- A General Organocatalytic System for Electron Donor-Acceptor Complex Photoactivation and Its Use in Radical Processes
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We report herein a modular class of organic catalysts that, acting as donors, can readily form photoactive electron donor-acceptor (EDA) complexes with a variety of radical precursors. Excitation with visible light generates open-shell intermediates under mild conditions, including nonstabilized carbon radicals and nitrogen-centered radicals. The modular nature of the commercially available xanthogenate and dithiocarbamate anion organocatalysts offers a versatile EDA complex catalytic platform for developing mechanistically distinct radical reactions, encompassing redox-neutral and net-reductive processes. Mechanistic investigations, by means of quantum yield determination, established that a closed catalytic cycle is operational for all of the developed radical processes, highlighting the ability of the organic catalysts to turn over and iteratively drive every catalytic cycle. We also demonstrate how the catalysts' stability and the method's high functional group tolerance could be advantageous for the direct radical functionalization of abundant functional groups, including aliphatic carboxylic acids and amines, and for applications in the late-stage elaboration of biorelevant compounds and enantioselective radical catalysis.
- De Pedro Beato, Eduardo,Melchiorre, Paolo,Spinnato, Davide,Zhou, Wei
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supporting information
p. 12304 - 12314
(2021/08/20)
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- Rational Design and Development of Low-Price, Scalable, Shelf-Stable and Broadly Applicable Electrophilic Sulfonium Ylide-Based Trifluoromethylating Reagents
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The development of two highly reactive electrophilic trifluoromethylating reagents (trifluoromethyl)(4-nitrophenyl)bis(carbomethoxy)methylide (1g) and (trifluoromethyl)(3-chlorophenyl)bis(carbomethoxy)methylide (1j) through structure-activity study was described. Under mild conditions, reagent 1g reacted with β-ketoesters and silyl enol ethers to give α-trifluoromethylated-β-ketoesters or α-trifluoromethylated ketones in high yields. In addition, reagent 1g could serve as a trifluoromethyl radical for a variety of trifluoromethylative transformations under visible light irradiation, including radical trifluoromethylation of electron-rich indoles and pyrroles and sodium aryl sulfinates as well as trifluoromethylative difunctionalization with styrene derivatives. On the other hand, as a complimentary, under reductive coupling conditions, reagent 1j reacted with a variety of (hetero)aryl iodides for the formation of trifluoromethylated (hetero)arenes.
- Ge, Hangming,Ling, Yijing,Liu, Yafei,Lu, Long,Shen, Qilong
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p. 1667 - 1682
(2021/05/28)
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- Scissoring Enaminone C=C Double Bond by Free Radical Process for the Synthesis of α-Trifluoromethyl Ketones with CF3SO2Na
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The C=C double bond cleavage on tertiary enaminones, enabling the formation of a new C-CF3 bond, has been realized as a practical method for the synthesis of α-trifluoromethyl ketones with only the promotion of TBHP and ambient heating. Control experiments support that the reactions proceed via a featured free radical process. The deuterium labeling experiment employing D2O indicates that water participated in the product formation by donating the hydrogen atom for the newly generated α-C-H bond in the product.
- Gan, Lu,Yu, Qing,Liu, Yunyun,Wan, Jie-Ping
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p. 1231 - 1237
(2020/12/21)
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- METHOD FOR PRODUCING α-FLUOROALKYL KETONE AND β-FLUOROALKYL ALCOHOL
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PROBLEM TO BE SOLVED: To provide a method for producing α-fluoroalkyl ketone and β-fluoroalkyl alcohol conveniently, inexpensively and efficiently. SOLUTION: A method for producing α-fluoroalkyl ketone represented by formula (II) (where Rf is a fluoroalkyl group) includes reacting an alkyne compound represented by formula (I) (where R1 is a chain hydrocarbon group, cyclic aliphatic hydrocarbon group, aromatic hydrocarbon group, heterocyclic group, -OR3, -NR4R4', R2 is a hydrogen atom, trialkylsilyl group, diallyl alkylsilyl group, or triallylsilyl group), in the presence of a radical initiator, with a fluoroalkyl sulfonic acid. SELECTED DRAWING: None COPYRIGHT: (C)2020,JPOandINPIT
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Paragraph 0073-0075
(2020/07/03)
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- A Concise and Efficient Approach to 2,6-Disubstituted 4-Fluoro pyrimidines from α-CF 3 Aryl Ketones
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Herein, a concise and efficient protocol to synthesize a series of 2,6-disubstituted 4-fluoropyrimidines as universal and useful building blocks in medicinal chemistry is reported. From readily accessible α-CF 3 aryl ketones and different amidine hydrochlorides, this method provides a very practical approach to this kind of compounds under mild conditions with good to excellent yields.
- Liu, Fangran,Qian, Qun,Yang, Chunhao,Zhang, Xiaofei
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supporting information
p. 273 - 280
(2019/12/28)
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- On the reactivity of anodically generated trifluoromethyl radicals toward aryl alkynes in organic/aqueous media
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An in-depth study of the reaction of electrochemically generated trifluoromethyl radicals with aryl alkynes in the presence of water is presented. The radicals are readily generated by anodic oxidation of sodium triflinate, an inexpensive and readily avai
- Jud, Wolfgang,Kappe, C. Oliver,Cantillo, David
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p. 3529 - 3537
(2019/04/14)
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- Direct Photoassisted α-Trifluoromethylation of Aromatic Ketones with Trifluoroacetic Anhydride (TFAA)
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Direct α-Trifluoromethylation of acetophenone derivatives was achieved by using trifluoroacetic anhydride (TFAA) as the trifluoromethyl source and pyridine-N-oxide (Py?O) as activator and oxidant under visible light irradiation and tris-(2,2′-bipyridine)ruthenium(II) hexafluorophosphate (Ru(bpy)3(PF6)2) as the photocatalyst. Different acetophenone derivatives could be converted to the corresponding α-CF3 derivatives with high selectivity. Extensive mechanistic investigation revealed the formation of vinyl trifluoroacetate as the key intermediate for this transformation. (Figure presented.).
- Das, Somnath,Hashmi, A. Stephen K.,Schaub, Thomas
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supporting information
p. 720 - 724
(2019/01/05)
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- Regioselective Gold-Catalyzed Hydration of CF3- and SF5-alkynes
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The regioselective gold-catalyzed hydration of CF3- and SF5-alkynes is described. The corresponding trifluoromethylated and pentasulfanylated ketones are obtained in up to 91% yield as single regioisomers showcasing the use of CF3 and SF5 as highly efficient directing groups in this reaction. Notably, this transformation represents the first use of CF3- and SF5-alkynes in gold catalysis.
- Cloutier, Mélissa,Roudias, Majdouline,Paquin, Jean-Fran?ois
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p. 3866 - 3870
(2019/05/24)
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- Organosilicon Reducing Reagents for Stereoselective Formations of Silyl Enol Ethers from α-Halo Carbonyl Compounds
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Salt-free stereoselective synthesis of silyl enol ethers was achieved by treating α-halo carbonyl compounds with 2,3,5,6-tetramethyl-1,4-bis(trimethylsilyl)-1,4-dihydropyrazine. In this reaction, easily removable trimethylsilyl halides and 2,3,5,6-tetramethylpyrazine were generated as the reaction byproducts. Due to the inertness of the reaction byproducts, we found a one-pot transformation of the in situ generated silyl enol ethers into various α-functionalized carbonyls by reaction with Togni-II reagent or aldehydes.
- Pramanik, Suman,Rej, Supriya,Kando, Shun,Tsurugi, Hayato,Mashima, Kazushi
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p. 2409 - 2417
(2018/02/23)
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- One-Pot Sequential Photoredox Chemistry and Asymmetric Transfer Hydrogenation with a Single Catalyst
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A sequential process is reported, in which different photoredox reactions are placed in sequence with asymmetric transfer hydrogenations of aryl ketones to provide a diverse set of chiral alcohols with enantioselectivities of up to 99 % ee. The method relies on a single chiral-at-metal catalyst which is added at the beginning of the two step sequence and only a final purification of the reaction product is required.
- Zhang, Xiao,Qin, Jie,Huang, Xiaoqiang,Meggers, Eric
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supporting information
p. 571 - 577
(2018/02/09)
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- Visible light induced Trifluoromethyl Migration: Easy Access to α-Trifluoromethylated Ketones from Enol Triflates
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Herein, we reported a novel method to synthesize α-trifluoromethylated ketones from enol triflates. Involving a cascade sulfur dioxide extrusion and a CF3 (trifluoromethyl) radical addition process, this reaction proceeds at room temperature an
- Liu, Shuyang,Jie, Jiyang,Yu, Jipan,Yang, Xiaobo
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p. 267 - 271
(2017/11/13)
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- Photooxidative Keto-Trifluoromethylation of Styrenes by Means of an Anthraquinone-Based Organocatalyst
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α-Trifluoromethyl ketones are versatile building blocks for the synthesis of various trifluoromethyl-functionalized molecules. Although there are significant advantages in the development of methods toward direct transformations of styrenes into α-trifluoromethyl ketones, most procedures leading to α-trifluoromethyl ketones require heavy- or transition-metal-based complexes. Herein, a novel method is developed for the synthesis of α-trifluoromethyl ketones via anthraquinone-catalyzed photooxidative keto-trifluoromethylation of styrenes with the readily available Langlois reagent (CF 3 SO 2 Na) under an oxygen atmosphere. The reactions proceed smoothly to give the products in moderate to excellent yield with good selectivity.
- Yamaguchi, Eiji,Kamito, Yuji,Matsuo, Kazuki,Ishihara, Jun,Itoh, Akichika
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p. 3161 - 3168
(2018/05/25)
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- Synthesis of Chloro(phenyl)trifluoromethyliodane and Catalyst-Free Electrophilic Trifluoromethylations
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The present work deals with a challenge in the synthesis of aryltrifluoromethyliodanes (ArICF3X) and develops a direct route to PhICF3Cl via a simple ligand-exchange reaction of PhI(OCOCF3)2, Me3SiCF3, and NaCl for the first time. The I-Cl bond length in PhICF3Cl supports its iodonium character, which enables an enhanced CF3-transfer capability in electrophilic S-, O-, N-, and C-trifluoromethylations as well as in catalyst-free trifluoromethylation-cyclizations of arylisonitriles.
- Xu, Cong,Song, Xiaoning,Guo, Jia,Chen, Sibao,Gao, Jie,Jiang, Jing,Gao, Fengyun,Li, Yuxin,Wang, Mang
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supporting information
p. 3933 - 3937
(2018/07/22)
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- Copper-Catalysed Decarboxylative Trifluoromethylation of β-Ketoacids
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An efficient method for Cu-catalyzed decarboxylative trifluoromethylation of β-ketoacids to achieve α-trifluoromethyl ketones was developed. A wide variety of synthetically useful α-trifluoromethyl ketones were obtained in modest to good yields under mild reaction conditions. The present method also exhibits good functional-group compatibility.
- Xu, Xiaolan,Chen, Huanhuan,He, Jianbo,Xu, Huajian
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p. 1665 - 1668
(2017/10/05)
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- Photoredox-catalysed redox-neutral trifluoromethylation of vinyl azides for the synthesis of α-trifluoromethylated ketones
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A redox-neutral, mild, and simple protocol is developed for the synthesis of α-trifluoromethylated ketones from vinyl azides under transition-metal-free conditions. In the presence of organic photoredox catalyst N-methyl-9-mesityl acridinium and sodium trifluoromethanesulfinate, a broad range of substituted vinyl azides were found to react smoothly upon visible-light irradiation, readily furnishing the corresponding products in satisfied yields.
- Qin, Hai-Tao,Wu, Shu-Wei,Liu, Jia-Li,Liu, Feng
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p. 1696 - 1699
(2017/02/10)
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- A redox-economical synthesis of trifluoromethylated enamides with the Langlois reagent
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A redox-economical strategy for the synthesis of trifluoromethylated enamides using copper catalysis is reported. The reaction employs the inexpensive Langlois reagent (CF3SO2Na) and takes place without the need of an external oxidant. The trifluoromethylated enamide products can easily be converted into the corresponding ketone, saturated amide or oxazole.
- Yang, Hai-Bin,Selander, Nicklas
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supporting information
p. 1771 - 1775
(2017/03/08)
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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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supporting information
p. 1338 - 1341
(2017/01/24)
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- Alpha-trifluoromethyl ketone compounds and preparation method thereof
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The invention discloses a preparation method of alpha-trifluoromethyl ketone compounds and the compounds. A series of alpha-trifluoromethyl ketone compounds containing various functional groups are synthesized under conditions of room temperature and illumination. The preparation method of the alpha-trifluoromethyl ketone compounds and the compounds have the following advantages: operation is simple, raw materials are cheap and available, an application range of substrates is wide, most substrates are high in yield, and harsh reaction conditions are avoided.
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Paragraph 0034; 0035; 0036
(2018/04/01)
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- Synthesis of α-Trifluoromethylated Ketones from Vinyl Triflates in the Absence of External Trifluoromethyl Sources
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A novel method for the conversion of vinyl triflates into α-trifluoromethylated ketones in the absence of external trifluoromethyl sources is described. This process accomplishes an efficient migration of the trifluoromethyl group of the triflate to the α-position in the ketone through a radical process. The reaction proceeds by the addition of a trifluoromethyl radical to the vinyl triflate and subsequent fragmentation of the trifluoromethane sulfonyl radical. Based on this reaction, a one-pot two-step procedure for the trifluoromethylation of ketones was developed. The method presented herein also allows the transfer of perfluoroalkyl groups from vinyl perfluoroalkanesulfonates, which are readily accessible from alkynes and perfluoroalkanesulfonic acids.
- Kawamoto, Takuji,Sasaki, Rio,Kamimura, Akio
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supporting information
p. 1342 - 1345
(2017/01/24)
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- Oxidative trifluoromethylation and fluoroolefination of unactivated olefins
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Fluorine-containing organic compounds are gaining increasing importance in medicinal chemistry. Described herein is a mild and efficient method for the radical addition of olefins with TMSCF3 and TMSCF2R (R = COOEt or CF3) to deliver various α-trifluoromethylated ketones and α-fluoroolefinated ketones.
- Wu, Ye-Bin,Lu, Guo-Ping,Yuan, Tao,Xu, Zhu-Bing,Wan, Li,Cai, Chun
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supporting information
p. 13668 - 13670
(2016/11/29)
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- Fenton reagent-catalyzed trifluoromethylation of enamines of 3-oxocarboxylates with CF3I
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The trifluoromethylation of enamines of ethyl 3-oxocarboxylates catalyzed by Fenton reagent with CF3I was investigated. Trifluoromethylation followed by acid hydrolysis provided 3-oxo-2-(trifluoromethyl)carboxylates in 64-94% yields, which were greater than those obtained by the trifluoromethylation of 3-oxocarboxylates as reported previously. Enamines trifluoromethylated at the 2-position were isolated as intermediates. Hydrolysis and successive decarboxylation of the obtained 3-oxo-2-(trifluoromethyl)carboxylates under acidic conditions provided (2,2,2-trifluoroethyl)ketones in satisfactory yields.
- Ohtsuka, Yuhki,Uraguchi, Daisuke,Yamamoto, Kyoko,Tokuhisa, Kenji,Yamakawa, Tetsu
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- METHOD FOR PRODUCING (2,2,2-TRIFLUOROETHYL)KETONE
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PROBLEM TO BE SOLVED: To provide a method for efficiently producing (2,2,2-trifluoroethyl)ketone that is an important compound as a pharmaceutical fluorine-containing building block. SOLUTION: The method produces (2,2,2-trifluoroethyl)ketone represented by formula (3) by reacting 3-oxo-2-(trifluoromethyl)propanoic acid ester represented by formula (1) under the presence of an acid. (R1 is an alkyl group of C1 to 4; R2 is a C1 to 8 alkyl group, etc. substituted/un-substituted with F.) SELECTED DRAWING: None COPYRIGHT: (C)2016,JPO&INPIT
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Paragraph 0096; 0099-0100; 0106-0107; 0114-0116
(2018/08/28)
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- Redox-ligand sustains controlled generation of CF3 radicals by well-defined copper complex
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A well-defined copper complex bearing iminosemiquinone ligands performs single electron reduction of an electrophilic CF3+ source into CF3 radicals. This redox behavior is enabled by the ligand which shuttles through two different redox states (iminosemiquinone and iminobenzoquinone) while the copper center is preserved as a Cu(ii). This system was used in the trifluoromethylation of silyl enol ethers, heteroaromatics and in the hydrotrifluoromethylation of alkynes. This is the first example of cooperative redox catalysis for the controlled generation of CF3 radicals.
- Jacquet, Jérémy,Blanchard, Sébastien,Derat, Etienne,Desage-El Murr, Marine,Fensterbank, Louis
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p. 2030 - 2036
(2016/03/05)
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- Activation of Trifluoromethylthio Moiety by Appending Iodonium Ylide under Copper Catalysis for Electrophilic Trifluoromethylation Reaction
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A novel iodonium-ylide compound 2 that appends atrifluoromethylthio (SCF3) group is disclosed as a new, shelf-stable electrophilic trifluoromethylation reagent. Unlike known shelf-stable electrophilic trifluoromethylation reagents, 2 has a stable SCF3 group which is activated by appending iodonium ylide under copper catalysis via sulfonium ylide to generate a cationic trifluoromethyl (CF3) species. Reagent 2 was found to be an efficient electrophilic trifluoromethylation reagent for a wide range of silyl enol ethers 3 under copper catalysis. Cyclic and acyclic α-trifluoromethyl ketones 4 were obtained by reagent 2 in moderate to good yields. On the other hand, a difluoromethylthio analogue 5 did not affect intermolecular transfer difluoromethylation to substrates. Instead, intramolecular 1,4-migration proceeded similar to the Stevens rearrangement to provide 6 in 21% yield, independent of the presence of nucleophiles 3.
- Saidalimu, Ibrayim,Suzuki, Shugo,Tokunaga, Etsuko,Shibata, Norio
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supporting information
p. 485 - 489
(2016/05/24)
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- NMP and O2 as Radical Initiator: Trifluoromethylation of Alkenes to Tertiary β-Trifluoromethyl Alcohols at Room Temperature
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A novel strategy was developed to trigger ·CF3 by using in situ generated peroxide in NMP under O2 or air as the radical initiator. Radical trifluoromethylation of alkenes was achieved toward tertiary β-trifluoromethyl alcohols. Various tertiary β-trifluoromethyl alcohols can be synthesized in good yields without extra oxidants or transition metal catalysts. Preliminary mechanistic investigation revealed that O2 diffusion can influence the reaction rate.
- Liu, Chao,Lu, Qingquan,Huang, Zhiyuan,Zhang, Jian,Liao, Fan,Peng, Pan,Lei, Aiwen
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p. 6034 - 6037
(2016/01/09)
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- FLUOROALKYLATION REAGENTS AND USES THEREOF
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Provided herein are halogen-bonded complexes of Formula (I), wherein is a halogen bond; R1 is unsubstituted C1-3 fluoroalkyl; D is N(R2)3, ((R2)2N)2C=NR2, 0=S(R2)2, substituted or unsubstituted heterocyclyl, or substituted or unsubstituted heteroaryl, and wherein R2 and y are as defined herein. D----(I??R1)y (I) Further provided are methods of preparing compounds of Formula (I), compositions, reagents, and kits comprising a compound of Formula (I), and methods for fluoroalkylating an organic compound using a compound of Formula (I).
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Paragraph 00201
(2015/11/23)
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- Carbene-Induced Intra- vs Intermolecular Transfer-Fluoromethylation of Aryl Fluoromethylthio Compounds under Rhodium Catalysis
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The intra- vs intermolecular transfer-fluoromethylation of aryl fluoromethylthio compounds is proposed. Finely designed ArSCF3 (1a) nicely releases its trifluoromethyl (CF3) group intermolecularly under rhodium catalysis, whereas a difluoromethylated analogue, ArSCF2H compound 1b shows intramolecular reaction. (Chemical Presented).
- Saidalimu, Ibrayim,Tokunaga, Etsuko,Shibata, Norio
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p. 4668 - 4672
(2015/08/18)
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- Sunlight-driven trifluoromethylation of olefinic substrates by photoredox catalysis: A green organic process
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The principles and utility of photoredox catalysis in organic synthesis are described. After a brief description of the features of the two types of catalytic photoredox processes following the reductive quenching cycle (RQC) and the oxidative quenching cycle (OQC), the discussion is focused on organic transformations based on OQC, in particular the trifluoromethylation of olefinic substrates with electrophilic trifluoromethylating reagents furnishing solvolytic addition products and substitution products. It is concluded that catalytic photoredox systems are green from the point of view of harmfulness, safety, and energy source (visible light, including sunlight). Future prospects of photoredox catalysis will be also discussed.
- Akita, Munetaka,Koike, Takashi
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p. 742 - 751
(2015/07/15)
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- Condensed-phase, halogen-bonded CF3I and C2F5I adducts for perfluoroalkylation reactions
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A family of practical, liquid trifluoromethylation and pentafluoroethylation reagents is described. We show how halogen bonding can be used to obtain easily handled liquid reagents from gaseous CF3I and CF3CF2I. The synthetic utility of the new reagents is exemplified by a novel direct arene trifluoromethylation reaction as well as adaptations of other perfluoroalkylation reactions. Its (no longer) a gas! A family of practical, liquid trifluoromethylation and pentafluoroethylation reagents enabled by halogen bonding is described. The synthetic utility of these reagents is exemplified by a novel direct arene trifluoromethylation reaction as well as adaptations of other perfluoroalkylation reactions.
- Sladojevich, Filippo,McNeill, Eric,B?rgel, Jonas,Zheng, Shao-Liang,Ritter, Tobias
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supporting information
p. 3712 - 3716
(2015/03/18)
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- Ambient benzotriazole ring opening through intermolecular radical addition to vinyltriazole
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Radical addition to vinyltriazole was developed as a new approach to achieve 1,2,3-triazole ring opening under mild conditions. Through reagent control, excellent chemoselectivity was achieved, giving either nitrile under basic conditions or quinoxaline under neutral conditions. Reactivities made this method an attractive new reaction mode.
- Su, Yijin,Petersen, Jeffrey L.,Gregg, Tesia L.,Shi, Xiaodong
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supporting information
p. 1208 - 1211
(2015/03/14)
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- Manganese-Catalyzed Aerobic Oxytrifluoromethylation of Styrene Derivatives Using CF3SO2Na as the Trifluoromethyl Source
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A mild and practical protocol for manganese-catalyzed aerobic oxytrifluoromethylation of olefinic bonds of styrene derivatives using CF3SO2Na (Langlois reagent) as the CF3 source is described. A distinguishing feature of this method is the generation of trifluoromethyl radicals from CF3SO2Na using the simple manganese salt/O2 system. The reaction proceeds under ambient conditions, free of added peroxide initiators, and provides moderate to good selectivities for alcohol versus ketone product.
- Yang, Yi,Liu, Yingle,Jiang, Yan,Zhang, Yu,Vicic, David A.
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p. 6639 - 6648
(2015/10/06)
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- Direct synthesis of α-trifluoromethyl ketone from (hetero)arylacetylene: Design, intermediate trapping, and mechanistic investigations
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Regioselective addition across the alkynes has been achieved in a silver-catalyzed protocol utilizing Langlois reagent (CF3SO2Na) and molecular O2 to access medicinally active α-trifluoromethyl ketone compounds. This metho
- Maji, Arun,Hazra, Avijit,Maiti, Debabrata
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supporting information
p. 4524 - 4527
(2015/01/09)
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- Continuous process for production of CuCF3 via direct cupration of fluoroform
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The first continuous flow process has been developed for the synthesis of a superior trifluoromethylating reagent, ligandless CuCF3, from fluoroform, by far the best CF3 source in terms of availability, cost, and atom economy. Optimization of the residence time and feed rates for CHF3 (gas), the cuprating reagent (premade from CuCl and t-BuOK in a 1:2 ratio) in DMF, and the stabilizer (Et3N· 3HF) at 23 °C and atmospheric pressure has allowed for the continuous production of CuCF3 in consistently high yields of up to 94%. The thus produced CuCF3 has been shown to be as highly efficient a trifluoromethylating agent as the one from the previously developed batch process.
- Mazloomi, Zahra,Bansode, Atul,Benavente, Pedro,Lishchynskyi, Anton,Urakawa, Atsushi,Grushin, Vladimir V.
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p. 1020 - 1026
(2014/11/08)
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- Combining photoredox-catalyzed trifluoromethylation and oxidation with dmso: Facile synthesis of α-trifluoromethylated ketones from aromatic alkenes
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Trifluoromethylated ketones are useful building blocks for organic compounds with a trifluoromethyl group. A new and facile synthesis of ketones with a trifluoromethyl substituent in the α-position proceeds through a one-pot photoredox-catalyzed trifluoromethylation-oxidation sequence of aromatic alkenes. Dimethyl sulfoxide (DMSO) serves as a key and mild oxidant under these photocatalytic conditions. Furthermore, an iridium photocatalyst, fac[Ir(ppy)3] (ppy=2-phenylpyridine), turned out to be crucial for the present photoredox process. Valuable α-CF3-substituted ketones can be synthesized from aromatic alkenes by combining photoredox-catalyzed trifluoromethylation and oxidation with DMSO. The iridium photocatalyst fac-[Ir(ppy)3] (ppy=2-phenylpyridine) plays key roles in this keto-trifluoromethylation. SET=single electron transfer.
- Tomita, Ren,Yasu, Yusuke,Koike, Takashi,Akita, Munetaka
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supporting information
p. 7144 - 7148
(2014/07/21)
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- Copper-catalyzed intermolecular trifluoromethylarylation of alkenes: Mutual activation of arylboronic acid and CF3+ reagent
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A novel copper-catalyzed intermolecular trifluoromethylarylation of alkenes is developed using less active ether-type Togni's reagent under mild reaction conditions. Various alkenes and diverse arylboronic acids are compatible with these conditions. Preliminary mechanistic studies reveal that a mutual activation process between arylboronic acid and CF3+ reagent is essential. In addition, the reaction might involve a rate-determining transmetalation, and the final aryl C-C bond is derived from reductive elimination of the aryl(alkyl)Cu(III) intermediate.
- Wang, Fei,Wang, Dinghai,Mu, Xin,Chen, Pinhong,Liu, Guosheng
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supporting information
p. 10202 - 10205
(2014/08/05)
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- A practical method for metal-free radical trifluoromethylation of styrenes with NaSO2CF3
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A mild and practical protocol for the metal-free trifluoromethylation of styrenes using NaSO2CF3 (Langlois reagent) and TBHP was developed. The approach provides efficient access to α-trifluoromethylated ketones and alcohols in moderate to good yields. Georg Thieme Verlag Stuttgart New York.
- Luo, Hai-Qing,Zhang, Zhi-Peng,Dong, Wen,Luo, Xu-Zhong
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supporting information
p. 1307 - 1311
(2014/06/10)
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- Synthesis of α-trifluoromethyl ketones via the Cu-catalyzed trifluoromethylation of silyl enol ethers using an electrophilic trifluoromethylating agent
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A method has been developed for the synthesis of α-trifluoromethyl ketones via the Cu-catalyzed trifluoromethylation of silyl enol ethers with an electrophilic trifluoromethylating agent, which produces a trifluoromethyl radical.
- Li, Lun,Chen, Qing-Yun,Guo, Yong
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supporting information
p. 5145 - 5152
(2014/06/23)
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- Highly efficient Cu(I)-catalyzed trifluoromethylation of aryl(heteroaryl) enol acetates with CF3 radicals derived from CF3SO 2Na and TBHP at room temperature
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An efficient method for the Cu(I)-catalyzed synthesis of α-trifluoromethyl ketones via the addition of CF3 to aryl(heteroaryl) enol acetates by using the readily available CF 3SO2Na (Langlois reagent) has been developed. The reaction is experimentally simple and carried out at room temperature, providing good to excellent yields with wide functional group tolerance.
- Lu, Yang,Li, Yaming,Zhang, Rong,Jin, Kun,Duan, Chunying
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supporting information
p. 128 - 133
(2014/05/06)
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- Continuous flow α-trifluoromethylation of ketones by metal-free visible light photoredox catalysis
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A continuous-flow, two-step procedure for the preparation of α-CF3-substituted carbonyl compounds has been developed. The carbonyl substrates were converted in situ into the corresponding silyl enol ethers, mixed with the CF3 radical source, and then irradiated with visible light using a flow reactor based on transparent tubing and a household compact fluorescent lamp. The continuous protocol uses Eosin Y as an inexpensive photoredox catalyst and requires only 20 min to complete the two reaction steps.
- Cantillo, David,De Frutos, Oscar,Rincon, Juan A,Mateos, Carlos,Kappe, C. Oliver
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p. 896 - 899
(2014/03/21)
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- PhI(OAc)2-mediated radical trifluoromethylation of vinyl azides with Me3SiCF3
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The fluorine-containing organic motif is becoming privileged in pharmaceuticals, agrochemicals, and functional materials, owing to its unique properties such as electron-withdrawing character, metabolic stability, and lipophilicity. Described herein is the PhI(OAc)2-mediated radical trifluoromethylation of vinyl azides with Me3SiCF3 to efficiently generate α-trifluoromethyl azines. The resulting α-trifluoromethyl azines were successfully transformed to valuable fluorine-containing molecules such as α-trifluoromethyl ketones, β-trifluoromethyl amines, 5-fluoropyrazoles, and trifluoroethyl isoquinolines. Trifluoromethylated diversity: The title reaction (see scheme) efficiently leads to α-trifluoromethyl azines, which were successfully transformed into valuable fluorine-containing molecules such as α-trifluoromethyl ketones, β-trifluoromethyl amines, 5-fluoropyrazoles, and trifluoroethyl isoquinolines. Copyright
- Wang, Yi-Feng,Lonca, Geoffroy Herve,Chiba, Shunsuke
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supporting information
p. 1067 - 1071
(2014/03/21)
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- Copper-mediated trifluoromethylation of propiolic acids: Facile synthesis of α-trifluoromethyl ketones
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Copper-mediated decarboxylative trifluoromethylation provides a new protocol for the efficient preparation of α-trifluoromethyl ketones from propiolic acids. It was found that water is involved as a reactant in the reaction, which is significantly different from the previously reported decarboxylative fluoroalkylation reactions.
- He, Zhengbiao,Zhang, Rui,Hu, Mingyou,Li, Lingchun,Ni, Chuanfa,Hu, Jinbo
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p. 3478 - 3483
(2013/11/19)
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- Reactions of trifluoromethyl-substituted arylacetylenes with arenes in superacids
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Protonation of the C≡C bond in trifluoromethyl-substituted arylacetylenes ArC≡CCF3 by the action of superacids (CF 3SO3H or HSO3F) generates vinyl cations ArC+=CHCF3 which react with arenes Ar′H to give alkenes Ar(Ar′)C=CHCF3. Protonation of the latter at the C=C bond in the reaction medium yields stable cations Ar(Ar′)C +-CH2CF3 which are converted into E/Z-isomeric alkenes Ar(Ar′)C=CHCF3 and/or alcohols Ar(Ar′)C(OH) CH2CF3 as a result of quenching of superacid reaction solution.
- Alkhafaji,Ryabukhin,Muzalevskiy,Osetrova,Vasilyev,Nenajdenko
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p. 327 - 341
(2013/07/26)
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- Sulfonation and trifluoromethylation of enol acetates with sulfonyl chlorides using visible-light photoredox catalysis
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A mild, practical method to prepare α-sulfonyl and α-trifluoromethyl ketones from readily available enol acetates and sulfonyl chlorides has been developed using visible-light photoredox catalysis. The method could be used with a wide range of enol acetates and sulfonyl chlorides, and gave the desired products in satisfactory to excellent yields. A practical method to prepare α-sulfonyl and α-trifluoromethyl ketones from enol acetates and sulfonyl chlorides using visible-light photoredox catalysis is presented. Copyright
- Jiang, Heng,Cheng, Yuanzheng,Zhang, Yan,Yu, Shouyun
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p. 5485 - 5492
(2013/09/02)
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- Oxidative trifluoromethylation of unactivated olefins: An efficient and practical synthesis of α-trifluoromethyl-substituted ketones
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An economical approach to α-CF3-substituted ketones, which are important intermediates in synthetic and medicinal chemistry, employs olefins and the readily available Langlois reagent (CF3SO 2Na). The reaction is operationally simple, proceeds at room temperature, and exhibits an excellent tolerance toward a wide variety of functional groups. Copyright
- Deb, Arghya,Manna, Srimanta,Modak, Atanu,Patra, Tuhin,Maity, Soham,Maiti, Debabrata
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supporting information
p. 9747 - 9750
(2013/09/23)
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