- Dibutyltin perfluoroalkanecarboxylates: Synthesis, NMR characterization and in vitro antitumour activity
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Three dibutyltin perfluoroalkanecarboxylates have been synthesized, characterized by 1H-, 13C-, 19F- and 117Sn-NMR, M?ssbauer, IR and mass spectroscopy. The structure of tetra-n-butylbis(trifluoroacetato)distann
- Kemmer, Martine,Dalil, Hassan,Biesemans, Monique,Martins, José C.,Mahieu, Bernard,Horn, Ernst,De Vos, Dick,Tiekink, Edward R. T.,Willem, Rudolph,Gielen, Marcel
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- Aerobic biotransformation studies of two trifluoromethoxy-substituted aliphatic alcohols and a novel fluorinated C3-based building block
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Fluorinated substances play a significant role for many industrial and consumer products, but many of these chemicals are attributed with an adverse ecological profile and persistence in the environment. Herein, three potentially more environmentally benign substitutes were assessed for aerobic biotransformation, namely 3-(trifluoromethoxy)-propan-1-ol (TFMPrOH), 6-(trifluoromethoxy)-hexan-1-ol (TFMHxOH) and 1-(2,2,3,3,4,4,4-heptafluorobutoxy)-propan-2-ol (HFBPrOH). Analytical techniques involved different HPLC-ESI-MS/MS techniques as well as determination of fluoride in order to assess the extent of mineralization. The two trifluoromethoxy-substituted alcohols showed very different results concerning mineralization. Whereas TFMPrOH only yielded approximately 15% fluoride, TFMHxOH reached nearly quantitative release of fluoride after 37 days. The latter one yielded 6-trifluoromethoxy hexanoic acid (TFMHxA) as well as trifluoromethyl carbonate (TFMC) as transient transformation products, both of which were entirely degraded. TFMC was also detected during biotransformation of TFMPrOH, however, the major transformation product was 3-trifluoromethoxy-propanoic acid (TFMPrA), which did not show any further degradation within a 47 days period. The third compound under investigation, HFBPrOH, expectedly yielded perfluorobutanoic acid as a stable biotransformation product. Several acidic biotransformation intermediates as well as heptafluorobutan-1-ol were identified and a biotransformation pathway was postulated. TFMHxOH might therefore be incorporated into fluorinated substances, for instance by ester linkages assuming that biotransformation of such substances would yield the alcohol.
- Fr?mel, Tobias,Knepper, Thomas P.
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- Oxidation of fluoroalkyl alcohols using sodium hypochlorite pentahydrate [1]
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Fluoroalkyl alcohols are effectivity oxidized to the corresponding fluoroalkyl carbonyl compounds by reaction with sodium hypochlorite pentahydrate in acetonitrile in the presence of acid and nitroxyl radical catalysts. Although the reaction proceeded slower under a nitroxyl radical catalyst- free condition, the desired carbonyl compounds were obtained in high yields. For the reaction with fluoroalkyl allylic alcohols, the corresponding α,β-epoxyketone hydrates were obtained in high yields.
- Kirihara, Masayuki,Suzuki, Katsuya,Nakakura, Kana,Saito, Katsuya,Nakamura, Riho,Tujimoto, Kazuki,Sakamoto, Yugo,Kikkawa, You,Shimazu, Hideo,Kimura, Yoshikazu
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- Electrocatalytic degradation of perfluorooctanoic acid by LaNixY1-xO3 (Y = Fe, Cu, Co, Sr) gas dispersion electrode
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Perfluorooctanoic acid (PFOA), as a refractory organic pollutant, seriously harms the environment and damages human health. Here, the electrocatalytic method was selected to degrade PFOA. In this work, perovskite catalysts doped with different elements, and corresponding gas diffusion electrodes (GDE) were prepared by the gel-sol method and citric acid complexation method. The crystal structure, microscopic morphology, and electrochemical properties of the LaNixY1-xO3 (Y = Fe, Cu, Co, Sr) perovskite catalyst electrode were analyzed by XRD, TEM, and CV. Moreover, the electrocatalytic performances of the as-prepared electrodes were assessed by the degradation of PFOA, and the Sr-doped GDE exhibited the highest degradation rate of PFOA. The optimum degradation conditions, such as the current density, pH, and initial concentration were also investigated. It was observed that when the current density was 20 mA/cm2, pH was 5, and initial concentration was 0.25 mmol/L, the Sr-doped GDE had the best degradation and defluorination efficiency of PFOA reached 90.0 % and 75.1 %, respectively. High performance liquid chromatography-mass spectrometry (HPLC-MS) was used to analyze the intermediate products of PFOA degradation and obtain the degradation pathway. With the combined action of [rad]OH and O2, PFOA was degraded by stepwise removal of CF2 groups, which were ultimately degraded into F? and CO2.
- Chen, Yongyang,Guo, Dan,Dong, Xiaochun,Li, Yahui,Huang, Yixuan,Chen, Hao,Li, Shanping
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- Heptafluorobutyric acid and preparation method of derivative thereof
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The invention provides a preparation method of heptafluorobutyric acid. The preparation method comprises the following steps: (A) carrying out an electrochemical fluoridation reaction on n-butyric acid, n-butyryl chloride or n-butyryl fluoride with anhydrous hydrogen fluoride, thus obtaining an electrolytic mixed gas, wherein the current density of the electrochemical fluoridation reaction is 0.025 to 0.033 A/cm, and the reaction temperature is 9 to 13 DEG C; a cooling reflux device is arranged in the electrochemical fluoridation reaction, and the temperature of a cooling medium of the cooling reflux device is -45 DEG C; (B) pumping the electrolytic mixed gas obtained in the step (A) into a reaction kettle filled with an acid-binding agent, thus obtaining heptafluorobutyryl fluoride, wherein the acid-binding agent is triethylamine; (C) mixing the heptafluorobutyryl fluoride obtained in the step (B) with water, and hydrolyzing, thus generating a heptafluorobutyric acid water solution; (D) mixing the heptafluorobutyric acid water solution with KOH, and naturally crystallizing until the concentration of the KOH is 40 to 45 percent, thus obtaining potassium heptafluorobutyrate; (E) acidizing the potassium heptafluorobutyrate by using sulfuric acid, thus obtaining the heptafluorobutyric acid.
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Paragraph 0102; 0105-0107
(2017/07/18)
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- Approaches to prepare perfluoroalkyl and pentafluorophenyl copper couples for cross-coupling reactions with organohalogen compounds
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The reactions of iodoperfluoroalkanes CnF2n+1I (n = 2, 3, 4) and n-BuLi at low temperatures give NMR spectroscopic evidence for LiCnF2n+1 which were converted into LiCu(CnF2n+1)2 derivatives upon treatment with 0.5 mol copper(i) bromide, CuBr. An alternative route to obtain perfluoroorgano copper couples, Cu(Rf)2Ag (Rf = n-C3F7, n-C4F9, C6F5) was achieved from the reactions of the corresponding perfluoroorgano silver(i) reagents, AgRf, and elemental copper through redox transmetallations. The composition of the resulting reactive intermediates was investigated by means of 19F NMR spectroscopy and ESI mass spectrometry. Perfluoro-n-propyl and perfluoro-n-butyl copper-silver reagents prepared by the oxidative transmetallation route exhibited good properties in C-C bond formation reactions with acid chlorides even under moderate conditions. Substitution of bromine directly bound to aromatics for perfluoroalkyl groups was achieved at elevated temperatures, while success in halide substitution reactions using lithium copper couples remained poor.
- Kremlev, Mikhail M.,Mushta, Aleksej I.,Tyrra, Wieland,Yagupolskii, Yurii L.,Naumann, Dieter,Sch?fer, Mathias
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p. 19693 - 19699
(2015/11/27)
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- The effect of oxygen in the photocatalytic oxidation pathways of perfluorooctanoic acid
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The influence of oxygen in the photocatalytic oxidation of perfluorooctanoic acid (PFOA) promoted by a commercial nano-sized titanium dioxide was studied by testing the reaction in different conditions: static air, oxygen flux, nitrogen flux and pre-saturated nitrogen flux. The reaction was monitored by Total Organic Carbon (TOC) analysis and Ionic Chromatography (IC). Shorter chain perfluorocarboxylic acids (PFCAs; Cn, n = 1-7) intermediate degradation products were quantitatively determined by High-Performance Liquid Chromatography combined with Mass Spectrometry (HPLC-MS) analysis. The presence of shorter chain PFCAs in solution was also monitored by 19F NMR. The experimental findings are in agreement with two major oxidative pathways: Cn → Cn-1 photo-redox and β-scissions routes mediated by COF2 elimination. Depending on the experimental conditions, the mutually operating mechanisms could be unbalanced up to the complete predominance of one pathway over the other. In particular, the existence of the β-scissions route with COF2 elimination was corroborated by the isolation and characterization of carbonyl difluoride, a predicted fluorinated decomposition by-product.
- Sansotera, Maurizio,Persico, Federico,Rizzi, Valentina,Panzeri, Walter,Pirola, Carlo,Bianchi, Claudia L.,Mele, Andrea,Navarrini, Walter
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p. 159 - 168
(2015/11/10)
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- A general, regiospecific synthetic route to perfluoroalkylated arenes via arenediazonium salts with RFCu(CH3CN) complexes
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A mild method of converting arylamines into perfluoroalkylated arenes is described. Relatively stable RFCu(CH3CN) complexes are used as perfluoroalkylating agents, which react smoothly with arenediazonium salts to produce various perfluoroalkylarenes in good yields. Based on the results of clock trapping experiments with diallyl ether, a radical process might be involved in the reaction.
- Jiang, Dong-Fang,Liu, Chao,Guo, Yong,Xiao, Ji-Chang,Chen, Qing-Yun
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supporting information
p. 6303 - 6309
(2015/03/30)
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- Nucleofugality of aliphatic carboxylates in mixtures of aprotic solvents and water
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The leaving group ability (nucleofugality) of fluoroacetate, chloroacetate, bromoacetate, dichloroacetate, trifluoroacetate, trichloroacetate, heptafluorobutyrate, formate, isobutyrate, and pivalate have been derived from the solvolysis rate constants of the corresponding X,Y-substituted benzhydryl carboxylates in 60 % and 80 % aqueous acetonitrile and 60 % aqueous acetone, applying the LFER equation: log k = sf(Ef + Nf). The experimental barriers (ΔG?,exp) for solvolyses of 11 reference dianisylmethyl carboxylates in these solvents correlate very well (r = 0.994 in all solvents) with ΔG?,model of the model σ-assisted heterolytic displacement reaction of cis-2,3-dihydroxycyclopropyl trans-carboxylates calculated earlier. Linear correlation observed between the log k for the reference dianisylmethyl carboxylates and the sf values enables estimation of the reaction constant (sfestim). Using the ΔG?,exp vs. ΔG?,model correlation, and taking the estimated sfestim, the nucleofugality parameters for other 34 aliphatic carboxylates have been determined in 60 % and 80 % aqueous acetonitrile and 60 % aqueous acetone. The most important variable that determines the reactivity of aliphatic carboxylates in aprotic solvent/water mixtures is the inductive effect of the group(s) attached onto the carboxylate moiety.
- Mati, Mirela,Denegri, Bernard,Kronja, Olga
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p. 375 - 384
(2015/10/12)
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- Synthesis and identification of solution-stable sulfenic acids: Perfluoroalkanesulfenic acids
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Taking advantage of the strong electron-withdrawing effect of perfluoroalkyl groups, solution-stable perfluoroalkanesulfenic acids were synthesized for the first time by Cope-type elimination of the corresponding imines; the acids were identified by 1H NMR, 19F NMR, and IR spectroscopy and mass spectrometry. Trapping reagents were utilized to capture the in situ generated sulfenic acids, which provided further experimental evidence for the formation of these fluorinated sulfenic acids. Owing to the strong electron-withdrawing effect of perfluoroalkyl groups (R f), solution-stable perfluoroalkanesulfenic acids are synthesized by Cope-type elimination of the corresponding imines at 80 °C; the acids are identified by 1H NMR,19F NMR, and IR spectroscopy and mass spectrometry. Trapping agents are used to capture the in situ generated sulfenic acids, which provides the experimental evidence. Copyright
- Li, Xiao-Bo,Xu, Ze-Feng,Liu, Li-Juan,Liu, Jin-Tao
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supporting information
p. 1182 - 1188
(2014/03/21)
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- Synthesis and Identification of Solution-Stable Sulfenic Acids: Perfluoroalkanesulfenic Acids
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Taking advantage of the strong electron-withdrawing effect of perfluoroalkyl groups, solution-stable perfluoroalkanesulfenic acids were synthesized for the first time by Cope-type elimination of the corresponding imines; the acids were identified by 1H NMR, 19F NMR, and IR spectroscopy and mass spectrometry. Trapping reagents were utilized to capture the in situ generated sulfenic acids, which provided further experimental evidence for the formation of these fluorinated sulfenic acids.
- Li, Xiao-Bo,Xu, Ze-Feng,Liu, Li-Juan,Liu, Jin-Tao
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supporting information
p. 1182 - 1188
(2015/10/05)
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- Free-radical selective functionalization of 1,4-naphthoquinones by perfluorodiacyl peroxides
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Perfluoroalkyl radicals, generated by thermal decomposition of perfluorodiacyl peroxides, react selectively with quinone rings of 1,4-naphthoquinones. In the presence of a non-conjugated alkene such as 1-hexene, perfluoroalkyl radicals add to the double bonds of the olefin forming a radical adduct, which selectively adds to the naphthoquinone ring. Several perfluorodiacyl peroxides have been synthesized and used for the direct and alkene-mediated functionalization of naphthoquinones. Geometrical parameters and electron density topology of all perfluorodiacyl peroxides have been calculated by the density functional formalism and quantum theory of atoms in molecules to attempt a rationalization of the experimental reactivity.
- Sansotera, Maurizio,Gambarotti, Cristian,Famulari, Antonino,Baggioli, Alberto,Soave, Raffaella,Venturini, Francesco,Meille, Stefano V.,Wlassics, Ivan,Navarrini, Walter
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p. 5298 - 5309
(2014/07/08)
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- Polyfluoroalkoxy phosphonic and phosphinic acid derivatives: II. Reversible esterase inhibitors
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Polyfluoroalkyl esters of phosphoric, alkylphosphonic and 1-hydroxypolyfluoroalkylphosphonic acids exhibited significant antiesterase activity against various esterases of animal and microbial origin. Moreover, with some compounds reversible inhibition of enzymes was observed due to the specific influence of hydrophobic fragments of the target products.
- Krutikova,Krutikov,Erkin
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experimental part
p. 434 - 439
(2010/08/04)
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- Efficient mineralization of hydroperfluorocarboxylic acids with persulfate in hot water
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The persulfate (S2O82-)-induced decomposition of hydroperfluorocarboxylic acids (H-PFCAs), that is, HCnF2nCOOH (n = 4, 6, and 8), in hot water was investigated, and the results were compared with the
- Hori, Hisao,Murayama, Misako,Inoue, Naoko,Ishida, Kyoko,Kutsuna, Shuzo
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experimental part
p. 131 - 136
(2010/08/20)
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- Free radical and isomerisation processes during the electrochemical fluorination of n-butyryl chloride, i-butyryl chloride and pivaloyl chloride in anhydrous hydrogen fluoride
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Electrochemical perfluorination (ECPF) of the title compounds containing primary, secondary and tertiary carbon atoms was carried out in anhydrous hydrofluoric acid (AHF). Detailed analysis of major and minor products suggest that carbon chain isomerisation involving cyclo-propane intermediate is more prevalent during ECPF of i-butyryl chloride when compared to n-butyryl chloride. Simple statistical probability involving free radical intermediates also support this observation. ECPF involving cyclo-propane intermediate is even more prevalent in pivaloyl chloride containing three methyl substituents. In this case, perfluorinated cyclo-propane intermediates were also observed in the product sample. Distribution of minor perfluorinated and partially fluorinated products also suggest the predominant role of normal free radical pathway involving single-electron transfer.
- Velayutham,Jayaraman,Kulangiappar,Ilayaraja,Babu, Y. Ram,Rao, P. Santhan,Reddy, S. Narayana,Babu, K. Victor,Noel
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p. 1111 - 1118
(2008/09/16)
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- Kinetics of the pH-independent hydrolyses of 4-nitrophenyl chloroformate and 4-nitrophenyl heptafluorobutyrate in water-acetonitrile mixtures: Consequences of solvent composition and ester hydrophobicity
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The pH-independent hydrolyses of 4-nitrophenyl chloroformate, NPCF and 4-nitrophenyl heptafluorobutyrate, NPFB in aqueous acetonitrile were studied spectrophotometrically from 15 to 45 °C. The binary solvent composition covers water concentrations from 2.
- El Seoud, Omar A.,Siviero, Fabio
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p. 793 - 802
(2007/10/03)
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- Photocatalytic decomposition of environmentally persistent perfluorooctanoic acid
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Perfluorooctanoic acid was photocatalytically decomposed by using TiO 2/Ni-Cu, and a small bias potential (-0.1 V) applied on TiO 2/Ni-Cu electrode greatly enhanced its decomposition. Copyright
- Chen, Jing,Zhang, Pengyi,Zhang, Li
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p. 230 - 231
(2007/10/03)
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- α-Branched-perfluorodiacyl peroxides: Preparation and characterization
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New perfluorodiacyl peroxides substituted at the α position have been synthesized and characterized. This class of peroxides shows good hydrolytic stability.
- Galimberti, Marco,Barchiesi, Emma,Navarrini, Walter
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p. 587 - 593
(2007/10/03)
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- Changing mechanisms in the β-cyclodextrin-mediated hydrolysis of phenyl esters of perfluoroalkanoic acids
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The rate of hydrolysis of esters CF3(CF2) nCOOPh (1 (n = 1), 2 (n = 2), and 3 (n = 6)) was measured at pH 6.00 and at pH higher than 9.00 in the presence of β-cyclodextrin (β-CD). For compounds 1 and 2 the reaction rate decreases as the β-CD concentration increases, and they show saturation effects at all pH. It is suggested that the substrate forms an inclusion complex with cyclodextrin. Analysis of the rate data allows calculation of the association equilibrium constant, KCD, the rate constant for the reaction of the included compound, kc, and KTS which is the hypothetical association equilibrium constant for the transition state of the cyclodextrin-mediated reaction. The dependence of log KCD and log KTS with the number of atoms in the chain is different. We suggest that the reactions of 1 and 2 take place with the perfluorinated alkyl chain included in the cavity, whereas the transition state for the reaction of phenyl trifluoroacetate involves a complex with the aryl ring inside the cavity. At low pH the inhibition comes from the protection of the carbonyl group toward nucleophilic attack by water. In basic pH the reaction of HO- as an external nucleophile is also inhibited. The cyclodextrin-mediated reaction involves the ionized OH group at the rim of the cyclodextrin cavity with poor efficiency due to an unfavorable orientation of the substrate in the complex. On the other hand, the reaction of compound 3 is strongly accelerated by cyclodextrin because the association of the substrate with cyclodextrin competes with the monomer-aggregate equilibrium and at high enough cyclodextrin concentration the main species present in solution is the complex between 3 and cyclodextrin.
- Fernandez, Mariana A.,De Rossi, Rita H.
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p. 6887 - 6893
(2007/10/03)
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- Solvolyis reactions of perfluoro-5-aza-4-nonene, C3 F7-CF=N-C4F9
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Hydrolysis of the imine perfluoro-5-aza-4-nonene, C3 F7-CF=N-C4F9, in ether was studied by several spectroscopic techniques including 17O NMR. The initial product is C3F7 -CO-NH-
- Siedle,Webb, Robert J.,Newmark,Brostrom, Myles,Weil, David A.,Erickson, Kristin,Behr, Fred. E.,Young Jr., Victor G.
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p. 175 - 182
(2007/10/03)
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- A novel catalytic pathway for perfluoroacyl peroxide synthesis
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matrix presented A new catalytic method for synthesis of bis(perfluoroacyl) peroxides (BPFAP) was elaborated by using hydrogen peroxide and perfluoroacyl anhydrides. The desired BPFAP were formed quantitatively in situ when perfluoroacyl anhydride was mixed with hydrogen peroxide (ratio ≥ 2:1) in the presence of a catalytic amount of the carboxylate RfCOO- M+. The essentially irreversible character of this process was shown experimentally and supported on the basis of DFT calculations. The synthesis of new acetyltrifluoroacetyl peroxides is also described.
- Krasutsky, Pavel A.,Kolomitsyn, Igor V.,Carlson, Robert M.
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p. 2997 - 2999
(2007/10/03)
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- Treatment of skin conditions by use of PPAR alpha activators
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Disorders of the skin and mucous membrane that have a disrupted or dysfunctional epidermal barrier are treated or prevented by topical application of compounds that are either activators of the farnesoid X receptor, activators of the peroxisome proliferator-activated receptor alpha , and oxysterol activators of the LXR alpha receptor. The same compounds are also effective in treating disorders of epidermal differentiation and proliferation.
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- Synthese de 3-perfluoroalkylprop-1-enes RF-CH2-CH=CH2
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The reactions of perfluoroalkyl iodides with allylbromide or chloride, in the presence of solid potassium hydroxide KOH give 3-perfluoroalkylprop-1-enes RFCH2CH=CH2 in good yields under mild conditions. This reaction represents a synthetically viable and convenient route to such compounds.
- Rubio,Blancou,Commeyras
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p. 171 - 175
(2007/10/03)
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- Multiple pathways in cyclodextrin-catalyzed hydrolysis of perfluoroalkylamides
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The hydrolysis of p-nitroanilide of perfluoroalkanoic acids, CF3(CF2)nCO-, with n = 1, 2, 3, 5, 6, and 7, 1a-f, was studied in the presence of β-cyclodextrin (CD). All reactions were catalyzed by CD through the formation of a 1:1 and 1:2 inclusion complexes. The association equilibrium constants for the 1:1 complexes were dependent on the number of carbons of the fluoroalkyl chain, whereas those of the 1:2 complexes were almost independent. These results indicate that, in the former case, the perfluoroalkyl chain is included, while in the latter, the CD unit encloses the aryl ring. For compounds 1a,b both complexes were more reactive than the substrate itself. The ratio of the reaction of complexed to uncomplexed substrate had its highest value for 1a in the case of the 1:1 complex, and for 1b, the 1:2 complex. This is attributed to the geometry of the complexes. Although compounds 1c-e reacted at the same rates in the free or 1:1 complexed form, CD accelerated the reactions because of an increase of the pKa of the substrate, which results in a higher concentration of the neutral reactive substrate at the same pH. Compound 1f formed aggregates even at 10-6 M concentration, and CD-induced deaggregation resulted in catalysis of the reaction.
- Granados, Alejandro,De Rossi, Rita H.
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p. 3690 - 3696
(2007/10/02)
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- Reaction of Perfluoroalkanesulfinates with Allyl and Propargyl Halides. A Convenient Synthesis of 3-(Perfluoroalkyl)prop-1-enes and 3-(Perfluoroalkyl)allenes
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The reaction of perfluoroalkanesulfinates, RfCF2SO2Na, with allyl and propargyl halides, in the presence of (NH4)2S2O8, gave 3-(perfluoroalkyl)prop-1-enes (RfCH2CH=CH2) and 3-(perfluoroalkyl)allenes (RfCH=C=CH2), respectively, in good yield.Evidence is presented for a radical addition-elimination mechanism for the reaction.The reaction represents a synthetically viable and convenient route to such compounds.
- Hu, Chang-Ming,Qing, Feng-Ling,Huang, Wei-Yuan
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p. 2801 - 2804
(2007/10/02)
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- SYNTHESIS OF PERFLUOROALKYL CARBOXYLIC ACIDS BY REACTION OF PERFLUOROALKYL IODIDES WITH ELECTROGENERATED SUPEROXIDE ION
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The electrogenerated superoxide ion O2 is shown to react with perfluoroalkyliodides to afford F-alkyl carboxylic acids.A mechanism is proposed on the basis of the results obtained in preparative experiments and by cyclic voltammetry.
- Amatore, C.
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p. 357 - 379
(2007/10/02)
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- TRANSFER OF THE DIAZO FUNCTION IN THE SERIES OF FLUORINATED 1,3-DIKETONES
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In the reaction of fluorinated 1,3-diketones with p-toluenesulfonyl azide under the conditions of diazo transfer hydrolytic elimination of the perfluoroacyl group occurs, and acyldiazomethanes are formed instead of the fluorine-containing diazo diketones.The reaction can be used for the synthesis of difficultly obtainable and labile 2-diazo ketones.
- Nikolaev, V. A.,Utkin, P. Yu.,Korobitsyna, I. K.
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p. 1059 - 1061
(2007/10/02)
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- Reaction of Bis(heptafluorobutyryl) Peroxide with Carbanions and a Thiolate Anion
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In the reaction of bis(heptafluorobutyryl) peroxide with carbanions and a thiolate anion, two types of reactions were observed; one is an electron transfer reaction to give perfluoropropylated compounds and the other is a nucleophilic substitution.
- Yoshida, Masato,Shimokoshi, Kazuaki,Kobayashi, Michio
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p. 433 - 436
(2007/10/02)
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- A NEW METHOD FOR THE PREPARATION OF PERFLUOROCARBOXYLIC ACIDS
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The reaction of both primary perfluoroalkyl iodides and bromides containing 3-12 carbon atoms with a rongalite-NaHCO3 reagent in aqueous dipolar aprotic solvents, such as DMF or DMSO, has been investigated.The reaction gave sodium perfluorocarboxylates in 51-86percent yields, and these were transformed to the respective perfluorocarboxylic acids by treatment with sulfuric acid.This provides a new method for the synthesis of perfluorocarboxylic acids.
- Huang, Bing-Nan,Haas, A.,Lieb, M.
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- Di-t-BUTYL NITROXYL-RADICAL INDUCED HOMOLYSIS OF POLYFLUORODIACYL PEROXIDES
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In the presence of di-t-butyl nitroxide (DTBNO) polyfluoro-diacylperoxides undergo rapid decomposition in n-pentane or CClF2-CCl2F at -50 to +20 degC.The reactions are first order in peroxide and DTBNO.On the basis of ESR observation of t-butyl polyfluoroalkyl nitroxides as well as product analysis, it appears that the decomposition processes involve DTBNO induced homolysis of the peroxy bonds followed by product formation steps.
- Zhao, Cheng-Xue,Chen, Guo-Fei,Wang, Xian-Shan,Jiang, Xi-kui
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p. 417 - 424
(2007/10/02)
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- The Decomposition of t-Butyl Heptafluoroperoxybutyrate in Aromatic and Aliphatic Solvents
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Kinetical studies and products analyses of the thermal decomposition of t-butyl heptafluoroperoxybutyrate (TBH) in benzene, octane, nitrobenzene, pyridine, and methoxybenzene have been carried out.In benzene and octane, the decoposition appears to be entirely a radical process.In nitrobenzene and pyridine, the reactions are found to give ionic decomposition proudcts exclusively.On the other hand, the decomposition of TBH in methoxybenzene is characteristic of mixed ionic and radical cleavages.
- Sawada, Hideo,Hagii, Hidehiko,Aoshima, Kazuyoshi,Yoshida, Masato,Kobayashi, Michio
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p. 3448 - 3452
(2007/10/02)
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- HEPTAFLUOROPROPYLATION OF ELECTRON-RICH OLEFINS WITH BIS(HEPTAFLUOROBUTYRIL) PEROXIDE
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Bis(heptafluorobutyril) peroxide reacted with electron-rich olefins to give the adducts of C3F7CO2 and C3F7 groups in good yields.The peroxide should be the useful reagent for the introduction of heptafluoropropyl moiety into olefins.
- Yoshida, Masato,Moriya, Koji,Sawada, Hideo,Kobayashi, Michio
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p. 755 - 758
(2007/10/02)
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- SYNTHESE D'ACIDES PERFLUORES DE HAUTS POIDS MOLECULAIRES
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Perfluorinated olefins of general formula CF3-(CF2)p-CF=CF-(CF2)m-CF3 (3 /= m + p /= 25) are oxidized by potassium permanganate or ruthenium tetroxide.The linear high molecular weight perfluorinated carboxylic acids so obtained are characterized by 19F N.M.R. spectroscopy.
- Battais, A.,Boutevin, B.,Pietrasanta, Y.,Sierra, P.
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- Acid anhydride to react with impurities in the production of perfluorocarboxylic acids
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Perfluorocarboxylic acids are produced by a metathesis reaction between an acid and a perfluoro acid fluoride in the presence of an acid anhydride. The perfluoroacid fluoride can conveniently be produced by electrochemical fluorination of the acyl fluoride co-product of the metathesis step. The acid anhydride present during the metathesis reaction serves the dual function of enhancing the desired reaction to produce the perfluorocarboxylic acid product and to react with impurities and by-products which would otherwise remain with the product and complicate its recovery.
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