- Parahydrogen-induced polarization transfer to 19F in perfluorocarbons for 19F NMR spectroscopy and MRI
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Fluorinated substances are important in chemistry, industry, and the life sciences. In a new approach, parahydrogen-induced polarization (PHIP) is applied to enhance 19F MR signals of (perfluoro-n-hexyl)ethene and (perfluoro-n-hexyl)ethane. Unexpectedly, the end-standing CF3 group exhibits the highest amount of polarization despite the negligible coupling to the added protons. To clarify this non-intuitive distribution of polarization, signal enhancements in deuterated chloroform and acetone were compared and 19F-19F NOESY spectra, as well as 19F T 1 values were measured by NMR spectroscopy. By using the well separated and enhanced signal of the CF3 group, first 19F MR images of hyperpolarized linear semifluorinated alkenes were recorded. Copyright
- Plaumann, Markus,Bommerich, Ute,Trantzschel, Thomas,Lego, Denise,Dillenberger, Sonja,Sauer, Grit,Bargon, Joachim,Buntkowsky, Gerd,Bernarding, Johannes
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- SYNTHESE DE PERFLUORO-nHEXYL-2 ETHANOL C6F13C2H4OH PAR REDUCTION ELECTROCHIMIQUE SUR FIBRES DE CARBONE DE PERFLUORO-nHEXYL-2 IODO-1 ETHANE C6H13C2H4I DANS LE SOLVANT N,N DIMETHYLFORMAMIDE
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Electrochemical reduction of 2-perfluoro-nhexyl-1-iodo-ethane at a carbon fibre cathode, in N,N-dimethylformamide as solvent, leads to the perfluoro-nhexyl-2-ethanol with perfluoro-nhexyl-2-ethylene as the major by-product.A mechanism is proposed on the basis of results obtained from macro-scale electrolysis and a study of Linear Sweep Voltammetry.
- Benefice-Malouet, S.,Blancou, H.,Calas, P.,Commeyras, A.
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- Fluorinated imidazolium salts having liquid crystal characteristics
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A family of fluorinated imidazolium salts showing liquid–crystalline properties in a wide temperature range was developed. These fluorinated ionic liquid crystals, due to their intrinsic hydrophobicity, high thermal stability and good conductivity, are suitable candidates to be used as electrolytes in electrochemical devices such as Dye Sensitized Solar Cell (DSSC) or lithium batteries.
- Zama, Isabella,Gorni, Giacomo,Borzatta, Valerio,Cassani, Maria Cristina,Crupi, Cristina,Di Marco, Gaetano
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- 2-(Perfluoroalkyl)ethanols by thermal alkylation of ambidentate lactams with 2-(perfluoroalkyl)-1-iodoalkanes, in the presence of added water. A change in mechanism and stoichiometry of the reaction. Isolation of a water adduct of the lactim ether intermediate
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Thermal alkylation of amides by an alkyl halide gives alcohols and esters, and the intriguing behavior of ambidentate lactams in this reaction with 2-(perfluoroalkyl)-1-iodoethanes and lactam 2 is summarized in Scheme 1.2-(Perfluoroalkyl)ethanols (3) are the principal alkylation product, and there is obtained a range of coproducts in varying amounts. A lactim ether salt (6·HI) is the first reaction intermediate in a sequence of reactions. For δ-valerolactam (8) or ε-caprolactam (11), conversion to 3 falls precipitously and R(F)CH=CH2 (4) becomes a major product. However, when water is introduced, alkylation rate of 2 by iodoalkane 1 increases, the conversion to 3 and 4 decreases, and a new lactim ether salt, 7.HI (the water adduct of 6·HI), is formed. Conversion to 3 is suppressed because coproduct 2 is weakly basic and the equilibrium lies on the side of the basic amine salt (7·HI). The mass spectrum of 2-hydroxy-2-[[(2-(perfluorohexyl)ethyl]oxy]pyrrolidine (7) includes the parent ion and a fragment (m/z = 131) of the intact pyrrolidine ring with an attached hydroxy group. Basic hydrolysis of product mixtures containing 7·HI in a protic solvent gives a high yield of 3 and 2. The higher lactams, 8 or 11, with 1 and water give the lactam salts efficiently; yield of 4 is low and yield of 3, by subsequent reaction with base, is high. With water present, the reaction rates of 8 and 1 are greater than for 2 and 1; water increases both the alkylation step and the water displacement step. Improved homogeneity of reaction mixtures and a specific solvent effect in which water stabilizes the bipolar transition state may be responsible for improved rates and yields.
- Brace
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- Quaternary ammonium ionic liquids containing fluorous ponytails: Competitive alkylation and elimination reactions of I(CH2) nRf (n = 2, 3) with tertiary amines
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The formation of quaternary ammonium iodides possessing a fluorine-containing chain has been investigated. Reactions of tertiary amines, such as i-PrMe2N and n-BuMe2N with I(CH2) n(CF2)m(CF3), (n = 2, m = 5 and 7) do not cleanly yield the anticipated quaternary ammonium halide salt, instead elimination occurs and [RMe2NH]I (R = i-Pr, n-Bu) and CH 2CH(CF2)m(CF3) are formed. This is confirmed by the crystallographic characterisation of [n-BuMe2NH]I which is found to adopt a micellar-type arrangement in the solid state. Increasing the spacer chain-length to n = 3 does result in the desired quaternary ammonium halide salts, [RMe2N(CH2) 3(CF2)m(CF3)]I, (m = 3, 7). Quaternisation of MeBuN((CH2)3C8F17) with 1-iodooctane gave the asymmetric quaternary ammonium salt possessing a fluorinated alkyl chain, [n-BuMeOctN((CH2)3C 8F17)]I. Unlike in previously studied perprotio systems, low symmetry ammonium systems possessing long fluorinated chains do not result in room temperature ionic liquids.
- Alhanash, Hana B.,Brisdon, Alan K.
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- Study of the alkylation of chlorosilanes. Part III. Synthesis and reactivity of new fluorinated organolithium reagents
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The effect of the structure of the fluoroalkyl group RFC2H4, where RF = CF3, C6F13 and (CF3)2CF, on the synthesis and reactivity of organolithium reagents RFC2H4Li towards trimethylchlorosilane, (CH3)3SiCl, and tris(fluoroalkyl)silanes R1R2R3SiF where R = RFC2H4, has been studied.As a result, new fluorinated organolithium reagents have been synthesized, as well as new silanes such as a tris(fluoroalkyl)fluorosilane, 2SiF(C2H4C6F13), and fluorinated tetraalkylsilanes such as C6F13C2H4Si(CH3)3 and 2Si(C2H4C6F13)(C2H4CF3).All the products have been characterized by 1H, 19F and 29Si NMR spectroscopy. - Keywords: Synthesis; Reactivity; Alkylation; Fluorinated organolithium reagents; NMR spectroscopy
- Boutevin, B.,Guida-Pietrasanta, F.,Ratsimihety, A.,Caporiccio, G.
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- Method for synthesizing perfluoroalkyl ethylene
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The invention provides a method for synthesizing perfluoroalkyl ethylene. The method comprises the following steps: stirring and mixing perfluoroalkyl ethyl iodide and an inorganic base solution, adding a phase transfer catalyst, stirring and heating, performing elimination reaction at 0-100 DEG C, after the reaction is completed, cooling the reaction liquid to the room temperature, leaving to stand and layer, separating the liquid, and washing the organic phase at a lower layer, thereby obtaining the product perfluoroalkyl ethylene. The method is simple in operation process, gentle in reaction condition, simple in product purification, free of organic solvent, and low in cost and safe and environmentally friendly as the phase transfer catalyst can be recycled.
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Paragraph 0028-0030
(2018/02/04)
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- Siloxane based syntheses of fluorous ethenes and their tandem Heck reactions with aryl iodides
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Perfluoroalkyl-ethenes (RfnCHCH2, 6a-c; a, n = 4; b, n = 6; c, n = 8) were prepared in good isolated yields (67-89%) and high purity (GC assay > 98%) from various fluorinated organosilanes in fluoride-anion assisted protodesilylation reactions. The environmentally more benign 'KF/NEt3/H2O' reagent combination introduced here was found as an effective substitute for the commonly used tetrabutylammonium- fluoride trihydrate (TBAF·3H2O) as a fluoride source. Fluorous styrenes ((E)-RfnCHCHAr, 8) were then prepared in good isolated yields (58-93%/iodoarene) and purities (GC assay > 95%) with the Pd(0) catalyzed Heck coupling of iodoarenes (Ar-I, 7) and perfluoroalkyl-ethenes generated in situ by the fluoride assisted cleavage of (β-perfluoroalkyl- α-iodo-ethyl)-siloxane ([RfnCH2CH(I)SiMe 2]2O, 3) precursors in DMF solution at elevated temperatures. They are accessible by the one-pot reaction of dimethylvinylchlorosilane (CH2CHSiMe2Cl, 2) and perfluoroalkyl iodides (Rfn-I, 1) as we reported earlier. Similarly, the radical chain addition of C8F17I to CH 2CHSi(OMe)3 (9) gave (β-perfluorooctyl-α-iodo- ethyl)-trimethoxysilane ([C8F17CH2CH(I)]Si(OMe) 3, 10) in good yield, which then was reacted with silica gel in dry toluene to obtain an SiO2-bonded (perfluorooctyl)ethene surrogate [silica(O)3SiCH(I)CH2C8F17, 11]. The fluoride assisted cleavage of 11 and tandem Heck reaction with iodobenzene afforded the appropriate cross-coupled product (E)-C8F 17CHCHPh.
- Csapo, Agnes,Rabai, Jozsef
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p. 79 - 85,7
(2020/09/16)
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- PROCESS FOR PRODUCING FLUORINATED (METH)ACRYLIC ESTER
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A mixture of fluoroalkyl iodides of the formula C2F5(CF2CF2)nI ( n is an integer of ≥0) wherein the sum of such fluoroalkyl iodides of n=3 and n=4 contained is ≥85 mol% is provided. This mixture is subjected to an ethylene addition step and an esterification step, and C2F5(CF2CF2)nCH=CH2 and C2F5(CF2CF2)nCH2CH2OH are removed. Thus, there can be obtained a mixture of fluorine-containing (meth)acrylic esters of the formula C2F5(CF2CF2)nCH2CH2OCOCR1=CH2 (wherein R1 represents a hydrogen atom or a methyl group, and n is an integer of ≥0) wherein the content of impurities (namely, olefins of the formula C2F5(CF2CF2)nCH=CH2 and alcohols of the formula C2F5(CF2CF2)nCH2CH2OH) is low.
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(2010/11/25)
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- PROCESS FOR PRODUCING FLUORINATED ACRYLIC ESTER
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A mixture of fluorine-containing acrylic esters represented by CF3(CF2)nCH2CH2OCOCR1=CH2 wherein R1 is a hydrogen atom, a methyl group or a halogen atom and "n" is an integer of at least zero is subjected to distillation under such conditions that the esters are not polymerized, so as to give a mixture of the esters with a less content of impurities (that is, olefins represented by CF3(CF2)nCH=CH2 and alcohols represented by CF3(CF2)nCH2CH2OH) at a high yield.
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(2008/06/13)
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- Process for producing a polyfluoroalkyl (meth)acrylate
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A process for producing a polyfluoroalkyl (meth)acrylate, which comprises isolating, from a reaction mixture containing a polyfluoroalkyl (meth)acrylate obtained by reacting a polyfluoroalkyl iodide of the formula CnF2n+1(CH2)mI (wherein n is an integer of from 2 to 7, and m is an integer of from 1 to 4) with a metal (meth)acrylate in tert-butanol, said polyfluoroalkyl (meth)acrylate by the following steps (1) to (3):(1) a step of taking out a crude liquid from the reaction mixture by solid-liquid separation;(2) a step of distilling the crude liquid to separate it into compound group A of compounds having a lower boiling point than the polyfluoroalkyl (meth)acrylate and compound group B of the polyfluoroalkyl (meth)acrylate and compounds having a higher boiling point than the polyfluoroalkyl (meth)acrylate; and(3) a step of distilling and purifying the polyfluoroalkyl (meth)acrylate from the compound group B in the presence of a polymerization inhibitor.
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- Synthesis of perfluoroalkyl-containing multifunctional groups compounds for textile finishing
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A new kind of perfluoroalkyl-containing multifunctional groups compound was designed. Treatment of 1H.1H.2H.2H-perfluorooctyltri- chlorosilane (4) with allylmagnesium bromide provided key intermediate 1H,1H,2H,2H-perfluorooctyltriallylsilane (2). Hydroboration followed by oxidation, epoxidation and dihydroxylation of 2 gave perfluoroalkyl-containing multifunctional groups compound 1a, 1b and 1c, respectively.
- Qing, Feng-Ling,Ji, Min,Lu, Ronghua,Yan, Kelu,Mao, Zhiping
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p. 139 - 141
(2007/10/03)
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- Nucleophilic displacements of 2-perfluoroalkyl-1-iodoethanes: Improved synthesis of fluorine-containing malonic esters
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The replacement of iodide in 2-perfluoroalkyl-1-iodoethanes by anions derived from dialkyl malonate affords α-(2-perfluoroalkyl)ethyl malonic esters in high yields with negligible elimination and dialkylation, using bases such as K2CO3/su
- Trabelsi,Szoenyi,Geribaldi
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p. 177 - 181
(2007/10/03)
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- Application of trimethylvinylsilane as a convenient synthetic precursor of (perfluoroalkyl)ethenes: An unusual fluoride-induced elimination-desilylation coupled reaction
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(equation presented) A convenient and effective method for the preparation of perfluoroalkylated ethenes is described. First, the free radical addition of perfluoroalkyl iodides to trimethylvinylsilane in the presence of AIBN gave iodoethylsilane intermediates (F(CF2)nCH2CHISiMe3, n = 4 (1), 6 (2),8 (3), 10 (4); 94-99%). Then an unusual dehydrohalogenation-desilylation reaction was effected by tetrabutylammonium fluoride, and finally the product isolation (F(CF2)nCH=CH2 (5-8), 62-87%) was facilitated using a fluorous phase separation technique. This novel approach can also be applied to adjust short C2 hydrocarbon units to functionalized fluorinated segments (e.g., HOCH2(CF2)8CH=CH2 (11), 71%). All structures were verified by state-of-the-art multinuclear one- and two-dimensional NMR experiments involving both homo-(19F-19F) and heteronuclear (1H-13C, 19F-13C) correlations based on the GMQFCOPS and inverse 1H and/or 19F detected GHSQC, GHMQC sequences with broad-band adiabatic 13C decoupling.
- Szlávik, Zoltán,Tárkányi, Gábor,G?m?ry, ágnes,Rábai, József
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p. 2347 - 2349
(2007/10/03)
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- Thermal alkylation of ambidentate lactams with 2-(perfluoroalkyl)-1-iodoalkanes. The effect of reaction conditions and ring size on the synthesis of 2-(perfluoroalkyl)ethanols and the mechanism of reaction
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The perfluoroalkylated long chain alcohols and their derivatives exhibit strong surface activity in solution and novel surface modification properties as adsorbed layers or films. A new, little known synthesis of 2-(perfluoroalkyl)ethanols (R(F)CH2CH2OH) employs a lactam, e.g., 2-pyrrolidinone (2), with an iodoalkane, e.g., C6F13CH2CH2I (1). Alkylation of 2 by heating with 1 gives C6F13CH2CH2OH (3) in 83% distilled yield, and treating the residual lactim ether salt (6·HI) with K2CO3 gives additional 3, up to 94% yield. Rate of alcohol formation (k(alc)) is unaffected by molar ratio of 2:1, yet rate of 1 reaction (k(iodo)) increases 2.44 times with doubling of 2:1 and side product C6F13CH = CH2 (4) decreases from 4 to 2%. For homologous lactams [(CH2)(n)NHC = O] (n = 3-5), selectivities (mol 3:4) are as follows: 5-membered ring, 18.4; 6-membered ring, 0.73; 7-membered ring, 0.13. Conversions to 3 are as follows: 6-membered ring, 19.4%; and 7-membered ring, 1.75%. A three-stop mechanism is proposed: (1) O-alkylation of the lactam by 1 gives lactim salt I; (2) N-substitution of salt I by another molecule of lactam forms a tetrahedral adduct (II); (3) breakdown of salt II gives 3 and iminolactam salt III. In model experiments, heating of 2 and lactim 6 yields 99% of 3 and iminolactam 5 and 1% of 4. By contrast, 7-membered 14 with 2 gives 45% of 3 and iminolactam 12, besides 4 and -caprolactam 16 (20%). For higher lactams, two competitive reactions can be discerned: (1) the S(N)2 displacement of alcohol by N-attack on salt II and a unimolecular, concerted fragmentation of the lactim, to lactam and alkene.
- Brace
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p. 2059 - 2071
(2007/10/02)
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- Synthesis and properties of fluorosilicon-containing polybutadienes by hydrosilylation of fluorinated hydrogenosilanes. Part 1. Preparation of the silylation agents
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The synthesis of new fluorinated hydrogenosilanes CnF(2n+1)(CH2)xC2H4Si(CH3)2H with n = 6 or 8 and x = 0 or 1 is presented.Such compounds were prepared in 85percent-90percent yield by the selective reduction of the corresponding fluorine-containing (dimethyl)chlorosilanes.These chlorinated derivatives were produced by the hydrosilylation of (dimethyl)chlorosilane with perfluoroalkylvinyl, CnF(2n+1)CH=CH2 (x = 0), or allyl, CnF(2n+1)CH2CH=CH2 (x = 1), olefins, both obtained from perfluoroalkyl iodides in two steps, the latter olefins being more reactive than the former.For all these steps, the influence of the spacer (C2H4 or C3H6) located between the fluorinated chain and the silicon atom with respect to the reactivity is discussed. - Keywords: Perfluoroalkyl iodide; Fluorinated olefin; Hydrosilylation; Reduction; Chlorofluorosilane; Polyfluoroalkyl(dimethyl)hydrogenosilanes
- Ameduri, B.,Boutevin, B.,Nouiri, M.,Talbi, M.
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p. 191 - 198
(2007/10/03)
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- Synthesis of telechelic dienes from fluorinated α,ω-diiodoalkanes. Part I. Divinyl and diallyl derivatives from model I(C2F4)nI compounds
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The synthesis of five fluorinated non-conjugated dienes from commercially available α,ω-diiodoperfluoroalkanes is described.Preparation of the fluorinated divinyl derivatives H2C=CH(CF2)nCH=CH2 (n = 2, 4, 6) (2,2, 2,4 and 2,6) was effected by ethylenation of these diiodinated compounds in various ways followed by dehydroiodination in ethanolic potassium hydroxide.Allyl diolefines, H2C=CHCH2(CF2)nCH2CH=CH2 (4,4 and 4,6) were produced by the α,ω-bis-telomerization of allyl acetate followed by deiodoacetoxylation in the presence of zinc.The diacetate precursors 3,4 and 3,6 of the respective diallyls 4,4 and 4,6 were obtained rather than diacetate 3,2 because of the eventual decomposition of α,ω-diiodoperfluoroethane by β-scission.These five fluorinated non-conjugated dienes have been characterized by 1H, 13C and 19F NMR spectroscopy. - Keywords:Telechelic dienes; Fluorinated vinyl dienes; Fluorinated allyl dienes; α,ω-Diiodoperfluoroalkanes; NMR spectroscopy
- Manseri, A.,Ameduri, B.,Boutevin, B.,Kotora, M.,Hajek, M.,Caporiccio, G.
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p. 151 - 158
(2007/10/02)
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- Amides as Nucleophiles: Reaction of Alkyl Halides with Amides or with Amides and Water. A New Look at an Old Reaction
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Heating of formamide with an alkyl halide (with or without water) affords a mild, nonhydrolytic, high-yield synthesis of alcohols and formate esters.Yet the way in which substitution on the alkyl halide actually occurs remains obscure.To explore this question, thermal reaction of 1-bromooctane (1a) with formamides (HC(O)NHR, R=H, Me; 2a, 2b) was studied quantitatively.Major products are 1-octanol (3) and n-octyl formate (5); minor products are 1-octene (4), di-n-octyl ether (6), and N-octylformamide (7, from 2a, only).Solid coproduct is HC(=NR)NHR + Br(1-) (e.g., 8a, R=H, methanimidamide hydrobromide).Analogously, 1a and N-methylformamide (2b) give alkylated products 3,5, and 6 along with 8b (R=Me). 1-Iodooctane (1b) reacts similarly.Probe samples show that 1-octanol (3) is first formed, followed by 5 and 6.Occurence of 8a-c is key to a mechanistic interpretation of the reaction.An imidate ("salt I"), e.g., from 1a and 2b, is first formed and reacts with amide 2b to give and 3.Now alcohol 3 is converted to ester 5 and 8b by reaction with this same formylamidine.Water, if present, adds to the imidate and gives a new tetrahedral intermediate that cleaves to ester 5 and amide salt, RNH3X.Analogous reaction steps are proposed to generate side products 4, 6, and 7.Alkylation of formamide by C6F13CH2CH2I (1c) is considerably slower and less efficient than alkylation by 1-bromooctane.This result stands in sharp contrast to fast, efficient reaction of 1c with N-methylformamide or with DMF and water.
- Brace, Neal O.
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p. 1804 - 1811
(2007/10/02)
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- SOME APPROACHES TO THE SYNTHESIS OF FLUORINATED ALCOHOLS AND ESTERS. III. SYNTHESIS OF 2-(F-ALKYL)ETHANOLS FROM 2-(F-ALKYL)-1-IODOETHANES AND AMIDES
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1-iodo-2-(F-alkyl)ethanes, RFCH2CH2I, when heated with a large excess of N-methylformamide (NMF) give in high yield, mixtures of predominately RFCH2CH2OH, some formate ester and a little RFCH=CH2.In a study of this process, significant variables were examined, including solvent, reactant ratio, effect of water, and alternative amide reactants.The coproduct from NMF is the amidine salt, (1+)*I(1-).By contrast, RFCH2CH2I with N,N-dimethylformamide (DMF) and water (one or two mols) gives chiefly the formate ester; the coproduct is Me2NH2(1+)*I(1-).A mechanistic scheme is proposed: in the first step, an alkyl imidate salt, e.g., F>(1+)*I(1-) is formed by O-alkylation of NMF; reaction of the imidate with more NMF gives a tetrahedral intermediate that breaks down rapidly to RFCH2CH2OH, and HC(=NHMe)NMeCHO(1+)*I(1-).The formate ester is derived from the alcohol and this N-formyl acylating agent, in a subsequent step.Analogously, the alkyl imidate salt from DMF and RFCH2CH2I reacts with water as nucleophile (but not with DMF) to give a tetrahedral intermediate that cleaves under stereoelectronic control to formate ester and amine salt, but not to alcohol.Quantitative isolation of amine salt and amidine salt, and observed rates of reaction give solid support to this proposed mechanism.
- Brace, Neal O.
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p. 151 - 174
(2007/10/02)
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- REACTION OF PERFLUOROALKYLETHYLENS WITH NUCLEOPHILES
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Perfluoroalkylethylenes react with some carbon-, oxygen-, sulfur-, selenium-, nitrogen-, and phosphorus-based nucleophiles by formal SN2' displacement of fluoride ion.
- Feiring, Andrew E.,Hovey, Michael C.,Arthur, Samuel D.
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p. 125 - 132
(2007/10/02)
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- Effect of a Perfluoroalkyl Group on the Elimination and Substitution Reactions of Two Homologous Series of Perfluoroalkyl-Substituted Iodoalkanes
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Substitution and elimination reactions of two homologous series of compounds, induced by strong bases, were studied in aqueous alcohol and anhydrous methanol solution.Series I compounds, RF(CH2)nI having n = 2 (RF = a perfluoroalkyl group, also named an F-alkyl group), gave only RFCH=CH2 under all conditions.By contrast, RF(CH2)3Igave 4-10 times as much substitution as elimination products.Isomerization of RFCH2CH=CH2 (6) to RFCH=CHCH3 (7) occurred; this result may account, in part, for the extremely high 7/6 alkene ratios (37-81/1) obtained from elimination reactions of RFCH2CHICH3.All series II compounds, RFCH2CHI(CH2) nCH3 (n = 0-5), gave entirely elimination, and principally toward the RF group.E/Z isomer ratios varied from 2.65 to 5.These results were compared to those obtained from 1- and 2-iodooctane under the same conditions.A practical synthesis of CF3(CF2)5CH2CH2CH2I is described; the isomeric (F-alkyl)propenes 6 and 7 were also separately prepared.Rates of reactions under standard conditions for both series I and II compounds were measured.Kinetically, only second-order processes were observed, but a sharp break occurred in rate as the RF group was separated more than two carbons from the departing iodine atom, in series I compounds.Series II compounds reacted about one-tenth as fast as series I compounds.These results are discussed in the context of previous work with F-alkyl-substituted compounds.
- Brace, Neal O.,Marshall, Lawrence W.,Pinson, Carol J.,Wingerden, Gail van
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p. 2361 - 2368
(2007/10/02)
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- OXYDATION ANODIQUE DE IODOPERFLUOROALCANES DANS LES ACIDES PERFLUOROALCANESULFONIQUES. PREPARATION DE NOUVEAUX ESTERS SULFONIQUES TOTALEMENT FLUORES RFSO3R'F A LONGUES CHAINES
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Perfluorinated sulphonic esters RFSO3R'F and fluorosulphates FSO3R'F, are easily obtained by anodic oxidation of iodoperfluoroalkanes R'FI in perfluoroalkene sulphonic acids RFSO3H (RF=CF3, C2F5, C4F9) and fluorosulphuric acid.With di-iodo compound I(CF2)4I, the mono and the diester can be selectively obtained.The alkaline hydrolysis of these esters produces perfluorinated carboxylic compounds.Polyfluorinated iodide R'FCH2CH2I are also oxidized in similar conditions.The mechanism of the electrolytic reaction is discussed.
- Germain, A.,Commeyras, A.
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p. 487 - 492
(2007/10/02)
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