- Further evidence on the importance of fluorous-fluorous interactions in supramolecular chemistry: A combined structural and computational study
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The solid-state structures of CF3(CF2)5CH2CO2H and a fluorous triazole are reported, both of which display a wide variety and large number of noncovalent interactions in their packing. The solid-state structure of CF3(CF2)5CH2CO2H is stabilized by multiple F···F contacts but only one C-H···F-C interaction, as well as O-H···O and C-H···O hydrogen bonds. In contrast to other reported structures, the torsion angles in the fluorous chain are close to 180°, which means that the fluorine atoms are eclipsed. A DFT study of the interactions in both compounds show that F···F interactions, along with stacking and C-H···F and C-H···O contacts, are individually weakly energetically stabilizing, but collectively, they can give rise to interaction energies of up to 13 kcal mol-1. A topological approach to the interactions using atoms-in-molecules (AIM) theory reveals that there are bond critical points between the C-F···F-C interactions as well as C-F···H-C interactions that are not recognized when using only the van der Waals distances.
- Omorodion, Harrison,Twamley, Brendan,Platts, James A.,Baker, Robert J.
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Read Online
- Environmentally friendly preparation method of fluorine-containing acrylate
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The invention relates to the technical field of preparation of new fluorine-containing materials, particularly to an environmentally friendly preparation method of fluorine-containing acrylate. The environmentally friendly preparation method comprises: carrying out a reaction on short-chain perfluoroiodoalkane and ethylene, separating, and purifying to obtain perfluoroalkylethyl iodide; carrying out hydrolysis on the perfluoroalkylethyl iodide, separating, and purifying to obtain perfluoroalkylethanol; and carrying out a reaction on the perfluoroalkylethanol and acrylic acid, separating, and purifying to obtain the product. According to the present invention, the perfluorooctyl-free product is synthesized, the potential risk of PFOA production cannot exist, and the obtained product is theenvironmentally friendly product, and meets the national industrial policy; the preparation method is simple, and is suitable for industrial production; and the reaction conversion rate is high, and the purity of the intermediate product is high, such that the subsequent reaction is easily performed, the yield is easily increased, and the cost is reduced.
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Paragraph 0024; 0027
(2019/01/06)
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- Method for preparing perfluoroalkyl ethanol
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The invention discloses a method for preparing perfluoroalkyl ethanol. The method comprises the following steps: enabling perfluoroalkyl ethyl iodide, a mixed solvent and water to react, and separating and purifying the obtained mixture containing perfluoroalkyl ethanol, by-product olefins, solvent salt and water, thereby obtaining the perfluoroalkyl ethanol product, wherein the separation and purification comprise the following steps: (1) adding a mixture containing perfluoroalkyl ethanol, by-product olefins, solvent salt and water into a rectifying tower for performing reduced pressure distillation, controlling the vacuum degree to be -0.91 to -0.96MPa so as to obtain distillate containing perfluoroalkyl ethanol, by-product olefins and water and bottom liquid, performing strong base treatment on the bottom liquid, and filtering to obtain the recycled mixed solvent; and (2) performing azeotropic distillation on the distillate, thereby obtaining the mixed solution of the by-product olefins and water and the product perfluoroalkyl ethanol. The method disclosed by the invention has the advantages of simplicity in process, greening, environment friendliness, convenience, high efficiency and low cost.
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Paragraph 0026-0032
(2017/11/29)
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- Perfluoroalkyl ethyl alcohols via perfluoroalkyl acetaldehydes
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A new route to commercially important perfluoroalkyl ethyl alcohols (RfCH2CH2OH) is described. This route involves the addition of perfluoroalkyl iodides to alkyl vinyl ethers using sulfinatodehalogenation chemistry, followed by catalytic hydrogenation of the intermediate mixture of perfluoroalkylacetaldehyde and perfluoroalkylacetaldehyde hemiacetal to the desired alcohol.
- Peng, Sheng,Moloy, Kenneth G.
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- Method for preparing perfluoroalkyl alcohol from perfluoroalkyl ethylene
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The invention discloses a method for preparing perfluoroalkyl alcohol from perfluoroalkyl ethylene.The method comprises the main steps that 1, a borane tetrahydrofuran solution is dropwise added into a dry three-opening bottle containing a perfluoroalkyl vinyl ether solution under the protection of nitrogen atmosphere; the mixture is stirred at the temperature of -20-25 DEG C, the reaction time is 8-24 h, after the reaction is finished, deionized water is added to decompose unreacted borane, and a reaction intermediate product is obtained; 2, inorganic strong base and a hydrogen peroxide aqueous solution are added into the reaction intermediate product, a reaction is performed for 0.5-3 h at the temperature of 0-50 DEG C, a solvent is removed after the reaction is finished, deionized water is used for washing, liquid separation is carried out, anhydrous magnesium sulfate is used for drying, and the perfluoroalkyl alcohol is prepared.The technological method is easy, the reaction can be performed under the normal pressure, the raw materials are rich and easy to obtain, the reaction efficiency is 100%, the yield is larger than 75%, and the method is suitable for industrial production.
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Paragraph 0026; 0028; 0029
(2017/04/03)
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- Synthesis of 2-(perfluoroalkyl)ethyl potassium sulfates based on perfluorinated Grignard reagents
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The first example of nucleophilic substitution with perfluoroalkyl Grignard reagents on the sp3 carbon centre is described. Thus, a series of organometals RF-MgBr, prepared from perfluorinated alkyl iodides RF-I with RF = C4F9, C 6F13, C8F17, C10F 21 and C12F25, reacted with 1,3,2-dioxathiolane-2,2-dioxide to afford the corresponding 2-(perfluoroalkyl) ethyl magnesium sulfates, which were isolated after metathesis to the corresponding potassium salts. In the model reaction, perfluorohexylmagnesium iodide was reacted with methyl triflate yielding polyfluorinated alkane. The attempts to extend the reaction to 1,3,2-dioxathiane-2,2-dioxide were unsuccessful due to its inferior reactivity and only reduced polyfluoroalkane and the product of coupling were detected in the reaction mixture. Polyfluorinated sulfates are easily hydrolyzed with hydrochloric or triflic acid to the corresponding alcohols, which is an alternative to standard transformation of perfluoroalkyl iodides to 2-(perfluoroalkyl)ethanols. Quantum-chemical calculations of the PES of the reaction with both sulfur-containing heterocycles found that the failure of the reaction with 1,3,2-dioxathiane-2,2-dioxide is caused by higher activation energy of the process.
- Paterová, Jana,Skalicky, Martin,Rybá?ková, Markéta,Kví?alová, Magdalena,Cva?ka, Josef,Kví?ala, Jaroslav
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experimental part
p. 1338 - 1343
(2011/02/22)
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- PROCESS FOR PRODUCING 2-PERFLUOROALKYLETHYL ALCOHOL
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In a first sulfation step, 2-perfluoroalkylethyl iodide is brought into contact with fuming sulfuric acid to obtain a reaction mixture comprising 2-perfluoroalkylethyl sulfate and bis(2-perfluoroalkylethyl)sulfate. Then, in a first hydrolysis step, 2-perfluoroalkylethyl sulfate produced in the first sulfation step is hydrolyzed to obtain a reaction mixture comprising 2-perfluoroalkylethyl alcohol. In a second sulfation step, bis(2-perfluoroalkylethyl)sulfate produced in the first sulfation step is brought into contact with fuming sulfuric acid to obtain a reaction mixture comprising 2-perfluoroalkylethyl sulfate. Then, in a second hydrolysis step, 2-perfluoroalkylethyl sulfate produced in the second sulfation step is hydrolyzed to obtain a reaction mixture comprising 2-perfluoroalkylethyl alcohol. According to such procedures, 2-perfluoroalkylethyl alcohol can be obtained in a high yield.
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Page/Page column 6
(2009/05/28)
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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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Page/Page column 8-9
(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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Page/Page column 6-7; 8-9
(2008/06/13)
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- Purification of fluorinated alcohols
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A process for reducing the level of perfluoroalkanoic acids, perfluoroalkanoic esters, and perfluoroalkyliodides in fluorinated alcohols comprising heating a fluorinated alcohol, or mixtures thereof, containing said acids, esters, or iodides to a temperature of at least 175° C. in the presence of water and a base additive is disclosed.
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Page/Page column 4-5
(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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- New insights on the asymmetric hydroboration of perfluoroalkenes
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Enantioselective access to Markovnikov regioisomeric perfluoroalcohols is achieved in the presence of chiral cationic rhodium complexes and specific hydroborating reagents.
- Segarra, Anna M.,Claver, Carmen,Fernandez, Elena
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p. 464 - 465
(2007/10/03)
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- Investigations into the use of a polyfluorooctanol as an auxiliary component for an aldol reaction
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Results are reported on the efficiency of polyfluorooctanol as a perfluorous auxiliary component in the aldol reaction between the enolate derived from polyfluorooctyl acetate and 2-fluorobenzaldehyde. Reduction of the corresponding polyfluoro β-hydroxy ester with Super Hydride gave the required 1,3-diol in good yield.
- Eames, Jason,Khanom, Hasina
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p. 266 - 277
(2007/10/03)
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- Catalysts for the preparation of fluorinated alcohols and process for the preparation of fluorinated alcohols
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The present invention provides a catalyst for preparing a fluorine-containing alcohol compound, the catalyst having at least one component selected from elements in Group 1B, Group 2B, Group 6A, Group 7A and Group 8 of the periodic table, ions of these elements, oxides containing these elements, hydroxides containing these elements and salts containing these elements, said component being supported on at least one complex oxide selected from Si—Al complex oxides, Al—P complex oxides and Si—Al—P complex oxides; and a method for preparing a fluorine-containing alcohol compound, the method comprising reacting a halogenated fluorine compound with water in the presence of the catalyst. According to the present invention, a fluorine-containing alcohol compound can be prepared at a relatively low reaction temperature and in a high yield.
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Page column 7; 9
(2008/06/13)
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- Investigation of the factors controlling the regioselectivity of the hydroboration of fluoroolefins
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Either Markovnikov or anti-Markovnikov regioselectivity can be achieved at will during the hydroboration-oxidation of perfluoroalkyl(aryl)ethylenes by varying the hydroborating agent.
- Ramachandran, P. Veeraraghavan,Jennings, Michael P.
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p. 386 - 387
(2007/10/03)
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- Critical role of catalysts and boranes for controlling the regioselectivity in the rhodium-catalyzed hydroboration of fluoroolefins
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(formula presented) Catalytic hydroboration of perfluoroalkylethylenes (RFCH=CH2) with cationic and neutral rhodium complexes allows for selective access to either regioisomeric alcohol after hydroboration with catechol- and pinacolboranes, followed by oxidation with alkaline hydrogen peroxide.
- Ramachandran, P. Veeraraghavan,Jennings, Michael P.,Brown, Herbert C.
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p. 1399 - 1402
(2008/02/09)
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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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p. 6504 - 6516
(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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- 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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- 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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p. 245 - 260
(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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- 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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