- OXIDATIVE ADDITION OF SUBSTITUTED ARSINES AND STIBINES WITH BIS(TRIFLUOROMETHYL)NITROXYL
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Reactions of bis(trifluoromethyl)nitroxyl with a number of methyl- and trifluoromethyl- substituted arsines and stibines at room temperature lead to the formation of pentavalent arsenic and antimony derivatives, namely (CH3)3-n(CF3)nM2 (M = As, n = 0, 1, 2; M = Sb, n = 0, 1).The derivatives yield bis(trifluoromethyl)-hyroxylamine and the corresponding dichlorides on treatment with hydrogen chloride.A free radical mechanism is proposed for the oxidative addition reactions.
- Ang, H. G.,Lien, W. S.
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- Rate constants for CF3 + H2 → CF3H + H and CF3H + H → CF3 + H2 reactions in the temperature range 1100-1600 K
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The shock tube technique coupled with H-atom atomic resonance absorption spectrometry has been used to study the reactions (1) CF3 + H2 → CF3H + H and (2) CF3H + H → CF3 + H2 over the temperature ranges 1168-1673 K and 1111-1550 K, respectively. The results can be represented by the Arrhenius expressions k1 = 2.56 × 10-11 exp(-8549K/T) and k2 = 6.13 × 10-11 exp(-7364K/T), both in cm3 molecule-1 s-1. Equilibrium constants were calculated from the two Arrhenius expressions in the overlapping temperature range, and good agreement was obtained with the literature values. The rate constants for reaction 2 were converted into rate constants for reaction 1 using literature equilibrium constants. These data are indistinguishable from direct k1 measurements, and an Arrhenius fit for the joint set is k1 = 1.88 × 10-11 exp(-8185K/T) cm3 molecule-1 s-1. The CF3 + H2 → CF3H + H reaction was further modeled using conventional transition-state theory, which included ab initio electronic structure determinations of reactants, transition state, and products.
- Hranisavljevic,Michael
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- Mixed-valence thiophosphorus compounds. Fluoro- and (trifluoromethyl)(thiophosphorylthio)phosphines with chiral phosphorus centers
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Reactions of the acids (CF3)2PS2H and F2PS2H with the fluoro(trifluoromethyl)aminophosphine CF3(F)PN(CH3)2 and the reaction of the new acid F(CF3)P(S)SH with the fluoro- or (trifluoromethyl)aminophosphines X2PN(CH3)2 (X = F, CF3) provide new isomeric (thiophosphorylthio)phosphines XYP(S)SPX′Y′ (X, Y, X′, Y′ = F, CF3) with chiral phosphorus centers. The compounds were characterized chemically and by NMR spectroscopy. Geminal CF3-CF3 (9.0 Hz for CF3 on pentavalent P; 7.2 Hz for CF3 on trivalent P) and F-F (82.5 Hz for F on pentavalent P; 92.5 Hz for F on trivalent P) coupling constants are revealed in the NMR spectra of the molecules as a result of the presence of the chiral phosphorus centers. Directly bound geminal fluorine atoms on trivalent P show large chemical shift difference between the two fluorine atoms (4.4 ppm) accompanied by substantially different 1JPF coupling constants (1370 and 1291 Hz). Similar but smaller differences prevail between geminal CF3 substituents. Reaction of the new acid F(CF3)P(S)SH with CF3(F)PN(CH3)2 gave a mixture of (thiophosphorylthio)phosphine isomers each with two chiral phosphorus centers. Only partial assignment of the major features of this spectrum could be made.
- Cavell, Ronald G.,Doty, Leon F.
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- REACTIONS OF BIS(TRIFLUOROMETHYL)NITROXYL WITH CF3PX2 (WHERE X=F, Cl, Br, I AND CN) AND P(CN)3
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The reactions between bis(trifluoromethyl)nitroxyl and CF3PX2 (where X=F, Cl, Br and CN) in 2:1 molar ratio give addition products, 2P(CF3)X2.The bromo and cyano products are unstable.The former decomposes at room temperature to give bromine and perfluoro-2-azapropene, and the latter yields predominantly (CF3)2NOCF3.With CF3PI2, iodine displacement occurs to afford 2PCF3.On the other hand, P(CN)3 affords 3PO, (CF3)2NON(CF3)2 and paracyanogen.Mechanisms for these reactions are proposed.
- ANG, H. G.,SO, K. K.
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- Non-Arrhenius Behaviour in the Reaction of CF3 Radicals with CH3CN and CD3CN
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Evidence is presented that rate measurements over a wide temperature range, 298-648 K, for the reaction of CF3 radicals with methyl cyanide show non-Arrhenius behaviour when the photolysis of trifluoromethyl iodide is used as a source radicals.The results presented here support the fact that the curved Arrhenius plot may be explained in terms of two reaction channels giving the same product, CF3H.One is the abstraction by the CF3 radicals and the other involves the iodine atom produced in the photolysis of CF3I.In order to obtain further information on the reaction mechanism the kinetic isotope effect has also been studied.
- Pasteris, L.,Staricco, E. H.
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- The gas-phase reaction of the CF3 radical with thiophene
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The reaction of CF3 radicals, generated by photolysis of CF 3I or hexafluoroacetone with thiophene, was studied in the gas phase at 25°C. At conversion of thiophene less than 20%, monosubstituted CF 3-thiophenes were found as the main reaction products, in addition to CF3H, C2F6, and monosubstituted dihydro-CF3-thiophene, the latter in very low proportion. An isomeric mixture of 2- and 3-CF3-thiophene was obtained in a ratio of about 16, independent of the radical source used (CF3I or hexafluoroacetone) to produce the CF3 radicals. A plausible mechanism that accounts for the observed products is proposed, and the reactivity of thiophene toward the CF3 radical at 25°C was determined as kadd/kc1/2 = 106 ± 4 cm3/2 mol-1/2 s-1/2.
- Herrera, Olga S.,Nieto, Jorge D.,Lane, Silvia I.,Oexler, Elena V.
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- Conversion of CFC-13 to trifluoroacetic acid by electrochemical reaction with carbon dioxide
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The electrochemical conversion of CFC-13 (CClF3) and carbon dioxide into trifluoroacetic acid (TFAA) was attempted at a Ag wire electrode under high pressure. TFAA was efficiently produced and the current efficiency was slightly dependent on the potential during electrolysis and pressure of co-existing carbon dioxide.
- Sonoyama, Noriyuki,Sakata, Tadayoshi
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- Trifluoromethylation et F-alkylation de l'acide sorbique
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5-Trifluoromethylhex-3-enoic and 5-F-alkylhex-3-enoic acids, respectively, are prepared in good yield by the reductive trifluoromethylation and F-alkylation of sorbic acid.
- Requirand, N.,Andrieu, A.,Blancou, H.,Commeyras, A.
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- Evaluation of the kinetic parameters for the reaction of trifluoromethyl radicals with CH3Cl in the gas phase in temperature range from 416 to 63 K
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The hydrogen and chlorine atom abstraction reactions from CH3Cl by CF3 radicals produced by the photolysis of hexafluoroacetone (HFA) and CF3I were studied relative to the recombination of CF3 radicals:
- Taccone,Olleta,Salinovich
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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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- Mechanistic study of nucleophilic fluorination for the synthesis of fluorine-18 labeled fluoroform with high molar activity fromN-difluoromethyltriazolium triflate
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The synthesis of fluorine-18 labeled fluoroform with high molar activity has grown in importance for the development of fluorine-18 labeled aryl-CF3radiopharmaceuticals that are useful as diagnostic radiotracers for the powerful technique of positron emission tomography (PET). We designed a strategy of synthesizing fluorine-18 labeled fluoroform fromN1-difluoromethyl-N3-methyltriazolium triflate (1)viaSN2 fluorination without stable fluorine isotope scrambling. Fluoroform was generated at rt in 10 min by fluorination of the triazolium precursor with TBAF (6 equiv.). We propose three routes (a), (b), and (c) for this fluorination. Quantum chemical calculations have been carried out to elucidate the mechanism of experimentally observed nucleophilic attack of fluoride at difluoromethyl groupviaroute (a), notN3-methylviaroute (b).1H and19F NMR studies using deuterium source have been performed to examine the competition between SN2 fluorination (route (a)) and the formation of difluorocarbene (route (c)). The observed superiority of SN2 pathway to formation of difluorocarbene in the reaction of the precursor using CsF in (CD3CN/(CD3)3COD (17.8?:?1)) gives the possibility of preparing the fluorine-18 labeled fluoroform in high molar activity.
- Chai, Jin Young,Cha, Hyojin,Lee, Sung-Sik,Oh, Young-Ho,Lee, Sungyul,Chi, Dae Yoon
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p. 6099 - 6106
(2021/02/12)
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- Aerobic Partial Oxidation of Alkanes Using Photodriven Iron Catalysis
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Photodriven oxidations of alkanes in trifluoroacetic acid using commercial and synthesized Fe(III) sources as catalyst precursors and dioxygen (O2) as the terminal oxidant are reported. The reactions produce alkyl esters and occur at ambient temperature in the presence of air, and catalytic turnover is observed for the oxidation of methane in a pure O2 atmosphere. Under optimized conditions, approximately 17% conversion of methane to methyl trifluoroacetate at more than 50% selectivity is observed. It is demonstrated that methyl trifluoroacetate is stable under catalytic conditions, and thus overoxidized products are not formed through secondary oxidation of methyl trifluoroacetate.
- Cao, Yuan,Coutard, Nathan,Goldberg, Jonathan M.,Groves, John T.,Gunnoe, T. Brent,Jeffrey, Philip D.,Jia, Xiaofan,Valle, Henry U.
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supporting information
(2022/01/11)
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- PROCESSES FOR PRODUCING TRIFLUOROIODOMETHANE USING METAL TRIFLUOROACETATES
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The present disclosure provides a process for producing trifluoroiodomethane. The process includes providing a metal trifluoroacetate, iodine, a phase transfer catalyst, and an organic solvent, and reacting the metal trifluoroacetate and iodine in the presence of the phase transfer catalyst and the organic solvent to produce trifluoroiodomethane.
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Paragraph 0025-0030
(2020/09/19)
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- PROCESSES FOR PRODUCING TRIFLUOROIODOMETHANE USING METAL TRIFLUOROACETATES
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The present disclosure provides a process for producing trifluoroiodomethane. The process includes providing a metal trifluoroacetate, an iodine source, a metal catalyst, and a solvent, and reacting the metal trifluoroacetate and the iodine source in the presence of the metal catalyst and the solvent to produce trifluoroiodomethane. The metal catalyst includes at least one selected from the group of ferrous chloride and zinc (II) iodide.
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Page/Page column 0033-0036
(2020/09/19)
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- Ph3P+CF2CO2 ? as an F? and :CF2 source for trifluoromethylthiolation of alkyl halides
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As trifluoromethylthiolation has received increasing attention recently, many CF3S-reagents and trifluoromethylthiolation methods have been developed. Herein we describe trifluoromethylthiolation of alkyl halides by using Ph3P+CF2CO2 ? as a fluoride and difluorocarbene source. Difluorocarbene is a versatile intermediate, but its side reactions are usually ignored and the by-products would therefore be discarded. In this work, a side reaction of difluorocarbene, the generation of a fluoride anion from difluorocarbene, was developed into a synthetic tool. Although the trifluoromethylthiolation reaction involved multi-sequential steps, the cleavage of C–F bond, the formation of CF2=S bond, F-C(S)F2 bond, and C-SCF3 bond, the conversion proceeded fast and was completed within 10 min.
- Liu, Zhuo,Long, Jin,Xiao, Xuan,Lin, Jin-Hong,Zheng, Xing,Xiao, Ji-Chang,Cao, Yu-Cai
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supporting information
p. 714 - 716
(2018/11/27)
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- Deacylative transformations of ketones via aromatization-promoted C–C bond activation
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Carbon–hydrogen (C–H) and carbon–carbon (C–C) bonds are the main constituents of organic matter. Recent advances in C–H functionalization technology have vastly expanded our toolbox for organic synthesis1. By contrast, C–C activation methods that enable editing of the molecular skeleton remain limited2–7. Several methods have been proposed for catalytic C–C activation, particularly with ketone substrates, that are typically promoted by using either ring-strain release as a thermodynamic driving force4,6 or directing groups5,7 to control the reaction outcome. Although effective, these strategies require substrates that contain highly strained ketones or a preinstalled directing group, or are limited to more specialist substrate classes5. Here we report a general C–C activation mode driven by aromatization of a pre-aromatic intermediate formed in situ. This reaction is suitable for various ketone substrates, is catalysed by an iridium/phosphine combination and is promoted by a hydrazine reagent and 1,3-dienes. Specifically, the acyl group is removed from the ketone and transformed to a pyrazole, and the resulting alkyl fragment undergoes various transformations. These include the deacetylation of methyl ketones, carbenoid-free formal homologation of aliphatic linear ketones and deconstructive pyrazole synthesis from cyclic ketones. Given that ketones are prevalent in feedstock chemicals, natural products and pharmaceuticals, these transformations could offer strategic bond disconnections in the synthesis of complex bioactive molecules.
- Xu, Yan,Qi, Xiaotian,Zheng, Pengfei,Berti, Carlo C.,Liu, Peng,Dong, Guangbin
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p. 373 - 378
(2019/05/22)
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- Nb-doped variants of high surface aluminium fluoride: A very strong bi-acidic solid catalyst
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A niobium doped high surface aluminium fluoride (HS-AlF3) catalyst was prepared, using an approach in which niobium doped aluminium hydroxide fluoride obtained via reaction of aqueous HF with the respective metal alkoxides in isopropanol is further fluorinated under flow of CHClF2 at 200 °C. A comparable procedure was used to synthesize a Nb-free variant for comparison. Both catalysts exhibit very strong Lewis acidic surface sites which are capable to activate strong carbon-halogen bonds at room temperature, just as the classical high-surface AlF3 (HS-AlF3), obtained by reacting aluminium isopropoxide with anhydrous HF, does. The catalysts were characterized by elemental analysis, P-XRD, MAS NMR spectroscopy, N2 adsorption, NH3-TPD, and pyridine photoacoustic FT-IR spectroscopy. In contrast to previously reported niobium doped HS-AlF3, which was prepared using anhydrous HF, the doped catalyst obtained via this aqueous HF-route shows excellent performance both in the isomerization of 1,2-dibromohexafluoropropane, a reaction that occurs only in the presence of the strongest Lewis acids, and in the cyclization of citronellal to isopulegol, a reaction which requires both, Lewis and Br?nsted acid sites.
- Marshall, Clara Patricia,Scholz, Gudrun,Braun, Thomas,Kemnitz, Erhard
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p. 6834 - 6845
(2019/05/27)
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- Connecting Organometallic Ni(III) and Ni(IV): Reactions of Carbon-Centered Radicals with High-Valent Organonickel Complexes
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This paper describes the one-electron interconversions of isolable NiIII and NiIV complexes through their reactions with carbon-centered radicals (R?). First, model NiIII complexes are shown to react with alkyl and aryl radicals to afford NiIV products. Preliminary mechanistic studies implicate a pathway involving direct addition of a carbon-centered radical to the NiIII center. This is directly analogous to the known reactivity of NiII complexes with R?, a step that is commonly implicated in catalysis. Second, a NiIV-CH3 complex is shown to react with aryl and alkyl radicals to afford C-C bonds via a proposed SH2-type mechanism. This pathway is leveraged to enable challenging H3C-CF3 bond formation under mild conditions. Overall, these investigations suggest that NiII/III/IV sequences may be viable redox pathways in high-oxidation-state nickel catalysis.
- Bour, James R.,Ferguson, Devin M.,McClain, Edward J.,Kampf, Jeff W.,Sanford, Melanie S.
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supporting information
p. 8914 - 8920
(2019/06/13)
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- Nickel(IV)-Catalyzed C-H Trifluoromethylation of (Hetero)arenes
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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-H trifluoromethylation of electron-rich arene and heteroarene substrates. Both experimental and computational mechanistic studies support a radical chain pathway involving NiIV, NiIII, and NiII intermediates.
- Meucci, Elizabeth A.,Nguyen, Shay N.,Camasso, Nicole M.,Chong, Eugene,Ariafard, Alireza,Canty, Allan J.,Sanford, Melanie S.
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p. 12872 - 12879
(2019/08/26)
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- Copper-Catalyzed Highly Stereoselective Trifluoromethylation and Difluoroalkylation of Secondary Propargyl Sulfonates
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It is challenging to stereoselectively introduce a trifluoromethyl group (CF3) into organic molecules. To date, only limited strategies involving direct asymmetric trifluoromethylation have been reported. Herein, we describe a new strategy for direct asymmetric trifluoromethylation through the copper-catalyzed stereospecific trifluoromethylation of optically active secondary propargyl sulfonates. The reaction enables propargylic trifluoromethylation with high regioselectivity and stereoselectivity. The reaction could also be extended to stereospecific propargylic difluoroalkylation. Transformations of the resulting enantiomerically enriched fluoroalkylated alkynes led to a variety of chiral fluoroalkylated compounds, thus providing a useful protocol for applications in the synthesis of fluorinated complexes.
- Gao, Xing,Xiao, Yu-Lan,Wan, Xiaolong,Zhang, Xingang
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supporting information
p. 3187 - 3191
(2018/02/26)
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- Bromotrifluoromethane: A Useful Reagent for Hydrotrifluoromethylation of Alkenes and Alkynes
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Bromotrifluoromethane (CF 3 Br) is a simple, inexpensive and abundant industrial material employed as a trifluoromethylating reagent. However, only limited strategies using CF 3 Br as a fluorine source are reported. Herein, we describe a visible-light-induced hydrotrifluoromethylation of alkenes and alkynes with CF 3 Br. The reaction proceeds under mild conditions with good functional group tolerance, providing a new route for the application of BrCF 3 in organic synthesis.
- Ren, Yu-Yan,Zheng, Xing,Zhang, Xingang
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supporting information
p. 1028 - 1032
(2018/05/01)
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- Stereodivergent synthesis of novel chiral C2-symmetric bis-trifluoromethyl-2-oxazolidinones
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A simplified effective synthetic process is described for the diastereoselective synthesis of the chiral C2-symmetric CF3-ureas (R,R)-15 and (S,S)-15 from (S)-α-phenylethylamine, glyoxal and CF3I.
- Remarchuk, Travis,Corey
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supporting information
p. 2256 - 2259
(2018/05/16)
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- C-F Bond Activation of P(C6F5)3 by Ruthenium Dihydride Complexes: Isolation and Reactivity of the missing Ru(PPh3)3H(halide) Complex, Ru(PPh3)3HF
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The major product of the reaction between Ru(IMe4)2(PPh3)2H2 (1; IMe4 = 1,3,4,5-tetramethylimidazol-2-ylidene) and P(C6F5)3 (PCF) is the five-coordinate complex Ru(IMe4)2(PF2{C6F5})(C6F5)H (2), which is formed via a complex series of C-F/P-C bond cleavage and P-F bond formation steps. In contrast, hydrodefluorination of all six ortho C-F bonds in PCF occurs with Ru(PPh3)4H2 to afford Ru(PPh3)3HF (3). NaBArF4 abstracted the fluoride ligand in 3 to give [Ru({η6-C6H5}PPh2)(PPh3)2H][BArF4], while B2pin2 reacted with 3 in C6D6 to yield a mixture of [Ru({η6-C6D6)(PPh3)2H]+ and Ru(PPh3)4H2. The treatment of 3 with HBpin (5 equiv) and HSiR3 (R = Et, Ph; 2 equiv) afforded Ru(PPh3)3(σ-HBpin)H2 and Ru(PPh3)3(SiR3)3H3, respectively. No stable substitution products were generated when 3 was reacted with Me3SiX (X = CF3, C6F5).
- Cybulski, Mateusz K.,Davies, Caroline J. E.,Lowe, John P.,Mahon, Mary F.,Whittlesey, Michael K.
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p. 13749 - 13760
(2018/10/20)
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- Reaction of arynes with trifluoroacetylated β-diketones: Novel formation of isocoumarins and phenanthrenes
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Polysubstituted isocoumarins were synthesized by the reaction of substituted 2-(trimethylsilyl)aryl triflates with trifluoromethylated β-diketones in the presence of CsF. The reaction proceeded through carbon-carbon bond insertion of aryne and intramolecular cyclization to form intermediates of alcohol anions, which extruded trifluoromethyl anion to afford isocoumarins. By using CuBr as a catalyst, 2 eq. of aryne reacted with β-diketones to afford phenanthrenes and 1,2-diarylethanones. Although reaction of 2-(trimethylsilyl)phenyl triflate with 1,1,1-trifluoro-4′-methylbenzoylacetone in the presence of CsF gave 3-(4′-methylphenyl)isocoumarin in 67% yield, addition of 0.2 eq. of CuCN resulted in the formation of 9-(4-methylbenzoyl)-10-trifluoromethylphenanthrene in 35% yield.
- Okuma, Kentaro,Tanabe, Yukiko,Fukami, Takuto,Ishibashi, Yuto
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- Method for preparing fluorinated compound CH2F-R (R is H or CF3) through difluoromethane pyrolysis
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The invention discloses a method for preparing a fluorinated compound CH2F-R (R is H or CF3) through difluoromethane pyrolysis. According the method, the fluorinated compound is obtained through a gas-phase reaction between difluoromethane and CH4, NH3, H2O or H under the circumstance that no catalyst exists. The following reaction conditions of the method are achieved: the reaction pressure is 0.1-1.5 MPa; the reaction temperature is 700-1000 DEG C; the mole ratio of difluoromethane to any one or more of CH4, NH3, H2O and H is 1:(0-40); and the residence time is 0.1-50 s. The method disclosed by the invention has the advantages that the raw material, namely difluoromethane, is easy to obtain; no catalyst needs to use; the operation and the control are easy; and the experimental repeatability is high.
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Paragraph 0038-0041
(2017/05/18)
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- Azidoperfluoroalkanes: Synthesis and Application in Copper(I)-Catalyzed Azide–Alkyne Cycloaddition
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We report an efficient and scalable synthesis of azidotrifluoromethane (CF3N3) and longer perfluorocarbon-chain analogues (RFN3; RF=C2F5,nC3F7,s
- Blastik, Zsófia E.,Voltrová, Svatava,Matou?ek, Václav,Jurásek, Bronislav,Manley, David W.,Klepetá?ová, Blanka,Beier, Petr
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supporting information
p. 346 - 349
(2016/12/30)
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- Metal-free and light-promoted radical iodotrifluoromethylation of alkenes with Togni reagent as the source of CF3 and iodine
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A light-promoted methodology for the iodotrifluoromethylation of alkenes was developed. For the first time a Togni reagent was exploited as the source of both the CF3 group and iodine atom. Preliminary mechanistic studies suggest that both CF3I and 2-iodobenzoic acid are direct sources of the iodine atom that is transferred to the products.
- Beniazza, Redouane,Douarre, Maxime,Lastécouères, Dominique,Vincent, Jean-Marc
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supporting information
p. 3547 - 3550
(2017/03/31)
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- Trifluoromethylation of Secondary Nitroalkanes
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Using a commercially available Umemoto's reagent, the metal-free trifluoromethylation of nitroalkanes is now possible. This method provides a general, high-yielding synthesis of α-(trifluoromethyl)nitroalkanes. The quaternary α-(trifluoromethyl)nitroalkanes obtained from this transformation can be elaborated to a variety of complex nitrogen-containing molecules, including α-(trifluoromethyl)amines.
- Gietter-Burch, Amber A. S.,Devannah, Vijayarajan,Watson, Donald A.
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supporting information
p. 2957 - 2960
(2017/06/07)
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- Selective reduction of a C–Cl bond in halomethanes with Et3GeH at nanoscopic Lewis acidic Aluminium fluoride
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The selective activation of C–Cl bonds of hydrochlorofluoromethanes and chloromethanes at moderate reaction conditions using ACF in a combination with Et3GeH is presented. The reactions of the chloromethanes (CH3Cl, CH2Cl2, CHCl3 and CCl4) in the presence of Et3GeH and ACF as catalyst led to the activation of only one C–Cl bond resulting in the hydrodechlorination. Friedel-Crafts reactions with benzene as solvent are suppressed by Et3GeH. A selective hydrodechlorination of hydrochlorofluoromethanes was achieved, because a transformation of a C–F bond into a C–H bond by the combination of ACF with Et3GeH did not occur. Supporting PulseTA experiments illustrated the interaction between the solid catalyst and Et3GeH, the solvent benzene or CH2Cl2.
- Mei?ner, Gisa,Feist, Michael,Braun, Thomas,Kemnitz, Erhard
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p. 234 - 241
(2017/09/12)
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- A Fortuitous, Mild Catalytic Carbon-Carbon Bond Hydrogenolysis by a Phosphine-Free Catalyst
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The putative catalyst trans-[Ru((S,S)-skewphos)(H)2((R,R)-dpen)] (skewphos=2,4-bis(diphenylphosphino)pentane; dpen=1,2-diphenylethylenediamine) transforms the trifluoroacetyl amide 2,2,2-trifluoro-1-(piperidin-1-yl)ethanone under mild conditions (4 atm H2, room temperature, 4-24h, 1 mol-% Ru, 15 mol-% KOtBu in tetrahydrofuran) to generate the formylated amine 1-formylpiperidine and fluoroform via C-C bond hydrogenolysis. Catalysts are also prepared by reacting cis-[Ru(η3-C3H5)(MeCN)2(COD)]BF4 (COD=1,5-cyclooctadiene) with diamine ligands in situ. Lowerature NMR studies provided insight into this reaction.
- Rasu, Loorthuraja,Rennie, Ben,Miskolzie, Mark,Bergens, Steven H.
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p. 561 - 564
(2016/06/01)
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- Copper(I)-mediated direct trifluoromethylthiolation of allylic halides with elemental sulfur and (trifluoromethyl)trimethylsilane
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Abstract A new method has been developed for the copper-mediated trifluoromethylthiolation of allylic halides by using potassium fluoride, elemental sulfur, and (trifluoromethyl)trimethylsilane in anhydrous N,N-dimethylformamide. This protocol provides facile access to a variety of allylic trifluoromethyl thioethers in moderate to good yields under mild, ligand-free reaction conditions.
- Li, Jue,Wang, Peiqiang,Xie, Fei-Fei,Yang, Xi-Gang,Song, Xiao-Nan,Chen, Wei-Dong,Ren, Jiangmeng,Zeng, Bu-Bing
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supporting information
p. 3568 - 3571
(2015/06/08)
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- CuCF3: A [18F]trifluoromethylating agent for arylboronic acids and aryl iodides
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Positron emission tomography has emerged as the leading method for medical imaging with fluorine-18 as the most widely used radioactive isotope. Here we report a semi-automated method for the preparation of valuable [ 18F]trifluoromethylcopper, as well as its use for the radiosynthesis of [18F]trifluoromethylarenes and heteroarenes. Mild conditions of [18F]trifluoromethylation make this method particularly useful for the radiosynthesis of pharmacologically relevant [18F] trifluoromethylarenes and heteroarenes. 18F Radiochemistry: A semi-automated method for the fast preparation of radiolabelled (trifluoromethyl)copper is reported (see scheme), thus making [ 18F]CuCF3 almost as accessible as [18F]fluoride itself for the preparation of radiolabelled trifluoromethylated probes. It can be used for the preparation of radiolabelled trifluoromethylarenes from arylboronic acids and aryliodides. This methodology is clean, efficient and consistent with the specific requirements of radiochemistry.
- Ivashkin, Pavel,Lemonnier, Gerald,Cousin, Jonathan,Gregoire, Vincent,Labar, Daniel,Jubault, Philippe,Pannecoucke, Xavier
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p. 9514 - 9518
(2014/08/18)
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- Fluoroform synthesis and uses thereof in the preparation of trifluoromethylated compounds
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The present invention relates to a process to prepare fluoroform (CHF3), notably radio labelled with fluorine-18, comprising a substitution reaction between CHAF2 and a fluoride salt, wherein A represents or as well as a process to prepare a composition comprising copper-based or silver-based trifluoromethylated reagents using notably the fluoroform thus prepared and the use of a composition comprising copper-based trifluoromethylated reagents or a mixture comprising a copper salt and a composition comprising silver-based trifluoromethylated reagents as a trifluoromethylating agent, notably radio labelled with fluorine-18.
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Paragraph 0105; 0106; 0107
(2014/10/15)
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- Electrochemical degradation of butyltrimethylammonium bis(trifluoromethylsulfonyl)imide for lithium battery applications
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Ionic liquids (ILs) are being considered as electrolytes for lithium ion batteries due to their low volatility, high thermal stability, and wide electrochemical windows which are stable at the strongly reducing potentials present in Li/Li+ batteries. Lithium metal deposition occurs under strongly reducing conditions and the effect that Li metal and any overpotential has on the stability of ILs is important in furthering the application of ILs in lithium based batteries. Here, N-butyl-N-trimethylammonium bis(trifluoromethylsulfonyl)imide was exposed to various potential differences in order to collect and characterize the volatile products. The IL produced more volatile products when exposed to strong reducing potentials which included reactive products such as hydrogen, alkanes, and amines. Water is a known contributor to hydrogen production in reducing environments, but the IL is also a source of hydrogen. If Li+ was present, the preferred pathway of reduction was plating of the lithium onto the working electrode, thus decreasing the reaction rate of degraded ILs.
- Klug, Christopher L.,Bridges, Nicholas J.,Visser, Ann E.,Crump, Stephen L.,Villa-Aleman, Eliel
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p. 3879 - 3884
(2014/08/05)
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- Xenon(IV)-carbon bond of [C6F5XeF2]+; Structural characterization and bonding of [C6F5XeF2][BF4], [C6F5XeF2][BF4]·2HF, and [C6F5XeF2][BF4]· n NCCH 3 (n = 1, 2); And the fluorinating properties of [C6F5XeF2][BF4]
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The [C6F5XeF2]+ cation is the only example of a XeIV-C bond, which had only been previously characterized as its [BF4]- salt in solution by multi-NMR spectroscopy. The [BF4]- salt and its new CH3CN and HF solvates, [C6F5XeF2][BF4]·1.5CH3CN and [C6F5XeF2][BF4]·2HF, have now been synthesized and fully characterized in the solid state by lowerature, single-crystal X-ray diffraction and Raman spectroscopy. Crystalline [C6F5XeF2][BF4] and [C6F5XeF2][BF4]·1.5CH3CN were obtained from CH3CN/CH2Cl2 solvent mixtures, and [C6F5XeF2][BF4]·2HF was obtained from anhydrous HF (aHF), where [C6F5XeF2][BF4]·1.5CH3CN is comprised of an equimolar mixture of [C6F5XeF2][BF4]·CH3CN and [C6F5XeF2][BF4]·2CH3CN. The crystal structures show that the [C6F5XeF2]+ cation has two short contacts with the F atoms of [BF4]- or with the F or N atoms of the solvent molecules, HF and CH3CN. The lowerature solid-state Raman spectra of [C6F5XeF2][BF4] and C6F5IF2 were assigned with the aid of quantum-chemical calculations. The bonding in [C6F5XeF2]+, C6F5IF2, [C6F5XeF2][BF4], [C6F5XeF2][BF4]·CH3CN, [C6F5XeF2][BF4]·2CH3CN, and [C6F5XeF2][BF4]·2HF was assessed with the aid of natural bond orbital analyses and molecular orbital calculations. The 129Xe, 19F, and 11B NMR spectra of [C6F5XeF2][BF4] in aHF are reported and compared with the 19F NMR spectrum of C6F5IF2, and all previously unreported J(129Xe-19F) and J(19F-19F) couplings were determined. The long-term solution stabilities of [C6F5XeF2][BF4] were investigated by 19F NMR spectroscopy and the oxidative fluorinating properties of [C6F5XeF2][BF4] were demonstrated by studies of its reactivity with K[C6F5BF3], Pn(C6F5)3 (Pn = P, As, or Bi), and C6F5X (X = Br or I).
- Koppe, Karsten,Haner, Jamie,Mercier, Hlne P. A.,Frohn, Hermann-J.,Schrobilgen, Gary J.
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p. 11640 - 11661
(2015/01/16)
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- Distinct mechanism of oxidative trifluoromethylation with a well-defined Cu(II) fluoride promoter: Hidden catalysis
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The fluoride [(bpy)CuF2(H2O)]·2H2O (1) reacts with CF3SiMe3 and PhB(OH)2 in DMF at rt to give PhCF3 in >95% yield within 15 min. Although 1 is a Cu(II) complex, this reaction occ
- Nebra, Noel,Grushin, Vladimir V.
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supporting information
p. 16998 - 17001
(2015/02/18)
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- On the feasibility of nickel-catalyzed trifluoromethylation of aryl halides
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A computational screening of 42 bidentate phosphines (PP) has yielded promising candidates for Ph-CF3 reductive elimination from Ni(II) complexes of the type [(PP)Ni(Ph)(CF3)]. The computed barriers and synthetic accessibility consid
- Jover, Jess,Miloserdov, Fedor M.,Benet-Buchholz, Jordi,Grushin, Vladimir V.,Maseras, Feliu
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p. 6531 - 6543
(2015/02/19)
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- Silver-mediated trifluoromethylation-iodination of arynes
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An unprecedented silver-mediated vicinal trifluoromethylation-iodination of arynes that quickly introduces CF3 and I groups onto aromatic rings in a single step to give o-trifluoromethyl iodoarenes has been developed. A new reactivity of AgCF3 has been revealed, and 2,2,6,6-tetramethylpiperidine plays an important role in this difunctionalization reaction.
- Zeng, Yuwen,Zhang, Laijun,Zhao, Yanchuan,Ni, Chuanfa,Zhao, Jingwei,Hu, Jinbo
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supporting information
p. 2955 - 2958
(2013/04/10)
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- Amidinate salt of hexafluoroacetone hydrate for the preparation of fluorinated compounds by the release of trifluoroacetate
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A powerful, new reagent, an amidinate salt of hexafluoroacetone hydrate, is an air-stable salt that can be used for the preparation of fluorinated organic molecules. Nucleophilic trifluoromethylation reactions are demonstrated following the base-promoted release of trifluoroacetate. This reagent is soluble in many polar organic solvents and produces fluoroform, following the release of trifluoroacetate. Reactions with this reagent and common electrophiles provide excellent yields of trifluoromethylated products.
- Riofski, Mark V.,Hart, Allison D.,Colby, David A.
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supporting information
p. 208 - 211
(2013/04/10)
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- Nucleophilic trifluoromethylation of carbonyl compounds: Trifluoroacetaldehyde hydrate as a trifluoromethyl source
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A feasible nucleophilic trifluoromethylating protocol has been developed using trifluoroacetaldehyde hydrate as an atom-economical trifluoromethyl source. The reaction was found to be applicable to the nucleophilic trifluoromethylation of a broad spectrum of carbonyl compounds with satisfactory yields in general. DFT calculations have been performed to provide mechanistic insight into the present and related reactions employing 2,2,2-trifluoro-1- methoxyethanol and hexafluoroacetone hydrate.
- Surya Prakash,Zhang, Zhe,Wang, Fang,Munoz, Socrates,Olah, George A.
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p. 3300 - 3305
(2013/06/27)
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- Preparation of trifluoroiodomethane via vapour-phase catalytic reaction between pentafluoroethane and iodine
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A new route for preparing C33I has been developed via a reaction between C2HF5 and I2. The influence of reaction temperature and active components of the catalysts on the amount of C33I was investigated. The result suggests that the selectivity of the C33I can be controlled by reaction conditions and active component of catalyst. The process for the formation of C33I and by-products is also discussed.
- Mao, Aiqin,Wang, Hua,Tan, Linhua,Nin, Xiangyang,Pan, Renming
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p. 4640 - 4642
(2013/07/19)
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- Compositions
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A composition comprising HCFO-1233xf and at least one additional compound selected from the group consisting of HCFO-1233zd, HCFO-1232xd, HCFO-1223xd, HCFC-253fb, HCFC-233ab, HFO-1234yf, HFO-1234ze, ethylene, HFC-23, CFC-13, HFC-143a, HFC-152a, HFO-1243zf, HFC-236fa, HCO-1130, HCO-1130a, HFO-1336, HCFC-244bb, HCFC-244db, HFC-245fa, HFC-245cb, HCFC-133a, HCFC-254fb, HCFC-1131, HCFO-1242zf, HCFO-1223xd, HCFC-233ab, HCFC-226ba, and HFC-227ca.
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Paragraph 0117; 0118
(2013/09/12)
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- Me3SiCF3/AgF/Cu - A new reagents combination for selective trifluoromethylation of various organic halides by trifluoromethylcopper, CuCF3
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An alternative copper halide-free route to obtain highly reactive trifluoromethylcopper species has been developed via the reaction of silver fluoride and trimethyl(trifluoromethyl)silane followed by a redox transmetallation with elemental copper. The composition of the reactive intermediate was investigated by means of UV/Vis/NIR, ESR, 19F NMR spectroscopy and ESI mass spectrometry. "Trifluoromethylcopper" prepared by the oxidative transmetallation route exhibits excellent reactivity and selectivity in substitutions of iodine or bromine bond to aromatic or heterocyclic compounds for trifluoromethyl groups without any additional catalyst.
- Kremlev, Mikhail M.,Mushta, Aleksej I.,Tyrra, Wieland,Yagupolskii, Yurii L.,Naumann, Dieter,M?ller, Angela
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body text
p. 67 - 71
(2012/03/10)
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- Copper-promoted trifluoromethylation of primary and secondary alkylboronic acids
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New couple: The Cu-promoted trifluoromethylation of primary and secondary alkylboronic acids with TMSCF3 extends the scope of transition-metal-catalyzed trifluoromethylation reactions to sp 3-hybridized carbon centers. It also repres
- Xu, Jun,Xiao, Bin,Xie, Chuan-Qi,Luo, Dong-Fen,Liu, Lei,Fu, Yao
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supporting information
p. 12551 - 12554
(2013/02/22)
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- Simple, stable, and easily accessible well-defined CuCF3 aromatic trifluoromethylating agents
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Give me an F: Exceptionally easy to make in over 90 yield (see scheme) and air-stable in the solid state, [(Ph3P)3Cu(CF3)] is a remarkable example of a rarely encountered well-defined Cu(I) trifluoromethylating agent and a convenient starting material for the synthesis of other CuCF3 complexes, such as [(phen)Cu(PPh3)(CF 3)]. Copyright
- Tomashenko, Olesya A.,Escudero-Adan, Eduardo C.,Martinez Belmonte, Marta,Grushin, Vladimir V.
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body text
p. 7655 - 7659
(2011/10/02)
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- Chloride ion-catalyzed generation of difluorocarbene for efficient preparation of gem-difluorinated cyclopropenes and cyclopropanes
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A chloride ion-catalyzed generation of difluorocarbene from a relatively non-toxic and inexpensive precursor, Me3SiCF2Cl (1), under mild and neutral conditions leads to an efficient preparation of gem-difluorocyclopropenes and difluorocyclopropanes through [2 + 1] cycloaddition reactions with alkynes and alkenes, respectively.
- Wang, Fei,Zhang, Wei,Zhu, Jieming,Li, Huaifeng,Huang, Kuo-Wei,Hu, Jinbo
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scheme or table
p. 2411 - 2413
(2011/04/15)
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- Chemical ionization using CF3+: Efficient detection of small alkanes and fluorocarbons
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The trifluoromethyl ion CF3+ is evaluated as a chemical ionization (CI) precursor in a compact Fourier Transform Ion Cyclotron Resonance (FTICR) mass spectrometer. It reacts with alkanes by hydride abstraction allowing characterization and quantification of alkanes up to C4 and cyclic. With larger alkanes fragmentation occurs. Fluorocarbons react by fluoride abstraction. Rate coefficients have been measured for reaction with alkanes, fluoroalkanes, chlorofluoroalkanes as well as several common VOCs. Use of CF3+ for trace analysis in air has been tested on an air sample containing traces of acetone, toluene, benzene and cyclohexane. The results are consistent with those obtained with H3O+ precursor and allow additional cyclohexane quantification.
- Dehon, Christophe,Lemaire, Jo?l,Heninger, Michel,Chaput, Aurélie,Mestdagh, Hélène
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experimental part
p. 113 - 119
(2011/08/21)
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- Copper-mediated trifluoromethylation of arylboronic acids by trifluoromethyl sulfonium salts
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The ligand-free trifluoromethylation of arylboronic acids with a [Ph 2SCF3]+[OTf]-/Cu(0) system has been carefully investigated. Aryl-, alkenyl- and heteroarylboronic acids with a variety of functional groups were suitable substrates for this reaction. It is suggested that a CuCF3 species is formed under the reaction conditions.
- Zhang, Cheng-Pan,Cai, Ji,Zhou, Chang-Bing,Wang, Xiao-Ping,Zheng, Xing,Gu, Yu-Cheng,Xiao, Ji-Chang
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supporting information; scheme or table
p. 9516 - 9518
(2011/10/02)
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- Cationic and radical intermediates in the acid photorelease from aryl sulfonates and phosphates
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The irradiation of a series of phenyl sulfonates and phosphates leads to the quantitative release of acidity with a reasonable quantum yield (≈0.2). Products characterization, ion chromatography analysis and potentiometric titration are consistent with the intervening of two different paths in this reaction, viz. cationic with phosphates and (mainly) radical with sulfonates. The Royal Society of Chemistry and Owner Societies 2011.
- Terpolilli, Marco,Merli, Daniele,Protti, Stefano,Dichiarante, Valentina,Fagnoni, Maurizio,Albini, Angelo
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experimental part
p. 123 - 127
(2012/01/03)
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- Method for producing 4,4,4- Trifluorobutane-2-One
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The present invention provides a novel method for preparing 4,4,4-trifluorobutane-2-one by providing a fluorobutene selected from the group consisting of 2,4,4,4-tetrafluoro-1-butene, (E)-1,1,1,3-tetrafluoro-2-butene, (Z)-1,1,1,3-tetrafluoro-2-butene, and mixture thereof; and reacting the fluorobutene(s) with a proton acid and water.
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Page/Page column 8
(2009/09/26)
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- PROCESSES FOR THE SYNTHESIS OF 3-CHLOROPERFLUORO-2-PENTENE, OCTAFLUORO-2-PENTYNE, AND 1,1,1,4,4,5,5,5-OCTAFLUORO-2-PENTENE
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Disclosed is a process comprising reacting CF3CF2CCI2CF2CF3 (CFC-41 -10mca) with hydrogen in the presence of a dehalogenation catalyst to produce CF3CF2CCI=CFCF3 (CFC-1419myx). Also disclosed herein is a process comprising reacting CF3CF2CCI=CFCF3 (CFC- 1419myx) with hydrogen in the presence of a dehalogenation catalyst to produce CF3CF2C≡CCF3 (octafluoro-2-pentyne). Also disclosed herein is a process comprising reacting CF3CF2CCI2CF2CF3 (CFC-41 -10mca) with hydrogen in the presence of a dehalogenation catalyst to produce CF3CF2C≡CCF3 (octafluoro-2-pentyne). In addition, a process for reacting CF3CF2C≡CCF3, in a pressure vessel, with a Lindlar catalyst and hydrogen to produce CF3CF2CH=CHCF3 (1,1,1,4,4,5,5,5-octafluoro-2- pentene) is disclosed.
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Page/Page column 14-15
(2009/07/18)
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- Tetrafluoropropene Production Processes
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A process is disclosed for producing 2,3,3,3-tetrafluoropropene and 1,3,3,3-tetrafluoropropene. The process involves pyrolyzing 1,1,1,2,3-pentafluoropropane.
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Page/Page column 2-3
(2009/10/30)
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- Preparation of trifluoroiodomethane via vapor-phase catalytic reaction between hexafluoropropylene oxide and iodine
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Based on our previous investigation on the reaction mechanism to produce difluorocarbene and subsequent CF3I starting with CHF3 and I2, a new route for preparing CF3I at a relative low temperature, 200 °C, has b
- Yang, Guang-Cheng,Jia, Xiao-Qing,Pan, Ren-Ming,Quan, Heng-Dao
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experimental part
p. 985 - 988
(2010/02/28)
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- PRODUCTION PROCESSES FOR MAKING 1,1,1,2,2,3-HEXAFLUOROPROPANE
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A process for making HFC-236cb is disclosed. The process comprises reacting TFE with HFC-32 in the presence of at least one co-product and a suitable catalyst to produce a product mixture comprising HFC-236cb, wherein the total amount of the at least one co-product is at least 10 ppmv based on the total amount of the tetrafluoroethylene, the difluoromethane and the at least one co-product.
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Page/Page column 12-13
(2008/06/13)
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- Nucleophilic trifluoromethylation of aryl halides with methyl trifluoroacetate
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When associated with an alkaline halide, such as cesium fluoride or cesium chloride, and Cu(I) species, methyl trifluoroacetate (MTFA) constitutes a valuable trifluoromethylating agent for substituting aromatic (or heteroaromatic) iodides and bromides. The reaction can be carried out in DMF at 180 °C or, better, in sulfolane which allows he reaction to proceed at a lower temperature (from 140 °C).
- Langlois, Bernard R.,Roques, Nicolas
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p. 1318 - 1325
(2008/02/10)
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- AZEOTROPE COMPOSITIONS COMPRISING NONAFLUOROPENTENE AND HYDROGEN FLUORIDE AND USES THEREOF
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Disclosed herein are azeotrope compositions comprising 1,2,3,3,3-pentafluoropropene and hydrogen fluoride. The azeotrope compositions are useful in processes to produce and in processes to purify 1,2,3,3,3-pentafluoropropene. Additionally, disclosed herein are azeotrope and near-azeotrope compositions comprising 1,1,1,2,3,4,4,5,5,5-decafluoropentane and hydrogen fluoride.
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Page/Page column 21-22
(2008/06/13)
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- PROCESS FOR THE MANUFACTURE OF CHLORODIFLUOROMETHANE
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A process is disclosed for the manufacture of CHClF2 which involves contacting CHCl3, HF and pentavalent antimony catalyst in the liquid phase; passing reactor vapor effluent to a reflux column to produce a reflux column vapor effluent of CHClF2 and HCl; passing the reflux column vapor effluent to a condenser to produce a condenser liquid effluent of CHClF2 and a condenser vapor effluent of CHClF2 and HCl; passing the condenser liquid effluent to the reflux column upper end; and recovering CHClF2 from the condenser vapor effluent. The concentration of CHCl2F and CHF3 in the condenser vapor effluent is controlled by: (i) controlling the temperature at a point within the lower third of the theoretical stages of the reflux column by controlling the heat input to the reactor liquid phase; (ii) controlling the pressure in the reactor, reflux column and condenser by controlling the rate at which the condenser vapor effluent is removed from the condenser; (iii) maintaining the reflux ratio of the condenser at a substantially constant value; and (iv) maintaining the reactor liquid phase at substantially the maximum mass that does not result in entrainment or flooding of the reflux column. Also disclosed is CHClF2 which is a product of this process. Also disclosed is a refrigerant comprising CHClF2 and a method for its manufacture, a polymer foam blowing blend comprising CHClF2 and a method for its manufacture, fluoromonomers tetrafluoroethylene and hexafluoropropylene produced by using CHClF2 and a method for their manufacture, and a fluoropolymer produced by using CHClF2 as a fluoromonomer precursor and a method for its manufacture; all involving the manufacture of CHClF2 in accordance with the above process.
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Page/Page column 20-22
(2008/06/13)
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- Bis(trifluoromethyl)phosphinous acid (CF3)2P-O-H: An example of a thermally stable phosphinous acid - Synthesis, gas-phase structure, and rotational isomers
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The bis(trifluoromethyl)-phosphinous acid, (CF3):P-O-H, is the only known example of a thermally stable phosphinous acid. Although this compound has been known since 1960, little is known about the chemistry of this extraordinary compound: this might be due to the tedious, and in some part risky, synthesis that was originally published. An improved, simple, and safe synthesis that is based on the treatment of the easily accessible (CF 3)2PNEt2 with at least three equivalents of p-toluene sulfonic acid, is presented. The reaction results in a complete conversion to the phosphinous acid, which is isolated in almost 90% yield. The compound exists in an equilibrium of two P-OH rotational isomers, a fact which is supported by quantum chemical calculations. The relative enthalpy difference of 6.4 kJ mol-1, calculated at the B3PW91/ 6-311G(3d,p) level, is in excellent agreement with the experimental value of 5.9 kJ mol-1, which was determined from the temperature dependence of the v(OH) bands of the two rotational isomers. The complete experimental vibrational spectra of both rotamers, their predicted vibrational spectra obtained by using quantum chemical calculations, and an attempt at photoinduced isomerization of matrix-isolated (CF3)2POH is presented. The experimental structure, obtained from an electron-diffraction study in the gas phase, is reproduced very well by ab initio and density functional theory (DFT) methods.
- Hoge, Berthold,Garcia, Placido,Willner, Helge,Oberhammer, Heinz
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p. 3567 - 3574
(2008/02/04)
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- Nitrogen trifluoride as an oxidative co-reagent in high temperature vapor phase hydrofluorinations
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Nitrogen trifluoride (NF3) has proven to be a useful additive in high temperature vapor phase hydrofluorination reactions of chlorocarbons. The activity of chromium-based catalysts is maintained by introducing a co-stream of NF3 into the reagent chlorocarbon and HF stream. NF3 is a desirable additive instead of O2 as there is no water generation due to its use.
- Belter, Randolph K.,Sweval, Mark S.,Iikubo, Yuichi
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p. 816 - 820
(2008/03/27)
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