- A general method for nearly reduction-free dehalogenations in a fluorinated biphasic system
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We have studied the dehalogenations of halofluorinated alkanes and fluorinated ethers, both linear and cyclic, as well as halofluorinated alkanes containing an aromatic moiety, to their corresponding unsaturated species in a biphase fluorinated/hydrogenated solvent system. The reactions in the biphase system lead to higher selectivities and better yields than those obtained performing the reaction in the traditional hydrogenated monophasic system. By this method, the concentrations of hydrogenated by-products of general formula R-CF2H or RCFHR' are as low as 100 ppm. This novel biphasic system provides therefore a useful synthetic route to materials and chemicals for electronics, optical polymers, plasma etching, etc. which require a very high purity of all compounds involved.
- Wlassics,Tortelli
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p. 359 - 365
(2008/12/22)
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- Dehalogenation process
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A process for obtaining vinyl compounds by dehalogenation of halofluorinated compounds having a linear, branched or cyclic structure, said halofluorinated compounds containing in the molecule at least one group: wherein Y1 and Y2, equal to or different from each other, are selected from Cl, Br, I; wherein the halofluorinated compounds are dehalogenated in the presence of a transition metal, or of transition metal couples, by operating in a biphasic system of solvents immiscible among each other, formed of a (per)fluorinated solvent and a dipolar aprotic or protic solvent (co-solvent), wherein the ratio moles co-solvent/equivalents of the halofluorinated compound ranges from 0.5 to 10, preferably from 0.5 to 5, still more preferably from 1 to 3.
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Page/Page column 5; 11
(2008/06/13)
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- Dehalogenation process
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A process for obtaining vinyl compounds by dehalogenation of halofluorinated compounds having a linear, branched or cyclic structure, said halofluorinated compounds containing in the molecule at least one group: wherein Y1 and Y2, equal to or different from each other, are selected from Cl, Br, I; wherein the halofluorinated compounds are dehalogenated in the presence of a transition metal, or of transition metal couples, by operating in a biphasic system of solvents immiscible among each other, formed of a (per)fluorinated solvent and a dipolar aprotic or protic solvent (co-solvent), wherein the ratio moles co-solvent/equivalents of the halofluorinated compound ranges from 0.5 to 10, preferably from 0.5 to 5, still more preferably from 1 to 3.
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Page/Page column 3
(2008/06/13)
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- New perfluorovinylethers through the bis(fluoroxy)difluoromethane (BDM) chemistry
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In the present work we give an overview of the CF2(OF) 2 radical reactivity and report the synthesis of new perfluorovinylethers. CF2=CF-OCF2OCF2 CF3 and CF2=CF-OCF2OCF2 CF2OCF3 are prepared in a semi-continuous methodology starting from CF2(OF)2. These highly reactive vinylethers are characterized by the OCF2O group directly bonded to the insaturation. For this reason they are excellent candidates for the preparation of very low Tg perfluororubbers.
- Navarrini, Walter,Corti, Sandra
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p. 189 - 197
(2007/10/03)
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- Process for preparing fluorohalogenethers
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A process for preparing (per)fluorohalogenethers having general formula (II): R′CF2OCFA-CA′F2 ??(II) wherein:— A and A′, equal to or different from each other, are H, Cl or Br but they cannot be both H; R′ has the following meanings: RO—, wherein R is a (per)fluorinated substituent, selected from the following groups: linear or branched C1-C20 alkyl; C3-C7 cycloalkyl; aromatic, C6-C10 arylalkyl or alkylaryl; C5-C10 heterocyclic or alkylheterocyclic; or a perfluoropolyether substituent T—Rf— wherein T=—OCF2OCFA-CA′F2, —OCF2XI, wherein XI=F, CF3, Cl; Rf is a perfluorooxyalkylene chain; by reaction of carbonyl compounds having formula R″COF (III) wherein R″=RO—, or R″=Q-Rf— wherein Q=—OCOF, —OCF2XI; in liquid phase with elemental fluorine and with olefinic compounds having formula CAF=CA′F (IV), at temperatures from ?120° C. to ?20° C.
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- Fluorovinylethers and polymers obtainable therefrom
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Fluorovinylethers having the formula CFX=CXOCF2OR, wherein R is a C2-C6 linear, branched or C5-C6 cyclic (per)fluoroalkyl group, or a C2-C6 linear, branched (per)fluoro oxyalkyl group containing from one to three oxygen atoms; when R is fluoroalkyl or fluorooxyalkyl group as above defined, it can contain from 1 to 2 atoms, equal or different, selected from the following: H, Cl, Br, I; X = F, H; and homopolymers or polymers obtainable polymerizing said fluorovinylethers with at least another polymerizable monomer.
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