- Synthese et polymerisation de monomeres fluores acryliques substitues en position α. Partie I. Synthese et polymerisation de l'α-(perfluorooctylmethyl) acrylate d'ethyle
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The synthesis of ethyl, α-perfluorooctylmethylacrylate (1), has been performed in three steps starting from perfluorooctylpropionic acid, with an overal yield of 82percent.Esterification of the acid by ethanol was followed by ethoxalylation in the α position (92percent yield).The last step involved the addition of formaldehyde on to the keto ester to produce an α-keto-γ-lactone which could be hydrolyzed in an aqueous basic medium to give the monomer 1 in 90percent yield.The homopolymerization of 1 is difficult but copolymerization with styrene and N-vinylp yrrolidone can be readily carried out.Elemental analysis and 1H NMR spectral data provide information on the copolymer composition.
- Bessiere, J. M.,Bachiri, A. El,Boutevin, B.
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- EXCIMER FORMATION AND PHASE SEPARATION OF HYDROCARBON AND FLUOROCARBON BILAYER MEMBRANES.
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The benzene chromophore contained in double-chain(hydrocarbon) ammonium amphiphiles gives both of monomer and excimer fluorescence in the fluid(liquid crystalline) bilayer organization. The excimer emission disappears by phase transition to the rigid(crystalline) bilayer. In contrast, the corresponding fluorocarbon bilayer, in the absence of phase transition phenomena, shows excimer emission at all temperatures(15-50 degree C). The excimer emission decreases when these probe amphiphiles are diluted in maxtrix bilayers. These results are applied to study the phase separation behavior of hydrocarbon and fluorocarbon bilayer membranes. The fluorocarbon bilayer is not extensively miscible with the hydrocarbon bilayer, and vice versa. The miscibility is influenced additionally by the chemical structure of amphiphiles. The rate of mixing is determined by the component miscibility as well as by the aggregate morphology.
- Kunitake,Tawaki,Nakashima
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- Fluorous derivatives of (1R,2R)-diaminocyclohexane as chiral ligands for metal-catalyzed asymmetric reactions
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Perfluoroalkyl-substituted, enantiopure diamines derived from (1R,2R)-diaminocyclohexane were conveniently prepared from readily available precursors. In situ generated metal complexes of these ligands were tested as chiral catalysts in three standard asymmetric reactions (cyclopropanation of styrene, hydrogen transfer reduction of acetophenone, and allylic alkylation of 1,3-diphenyl-2-propenyl acetate) affording enantioselectivities of up to 47% in the copper-catalyzed cyclopropanation of styrene.
- Bayardon, Jerome,Sinou, Denis,Holczknecht, Orsolya,Mercs, Laszlo,Pozzi, Gianluca
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p. 2319 - 2327
(2007/10/03)
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- Combining lipase-catalyzed enantiomer-selective acylation with fluorous phase labeling: A new method for the resolution of racemic alcohols
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Lipase-catalyzed acylation of racemic alcohols with a highly fluorinated acyl donor allows their kinetic resolution accompanied by the simultaneous enantiomer-selective fluorous phase labeling. Both the tagged and the untagged enantiomer can be separated without chromatography by a very efficient partition between a fluorous and an organic phase. The method has been successfully applied to the resolution of typically racemic secondary alcohols of low molecular weight. The fluorous label can be recovered quantitatively.
- Hungerhoff, Benno,Sonnenschein, Helmut,Theil, Fritz
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p. 1781 - 1785
(2007/10/03)
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- Synthesis and preliminary biochemical assessment of ethyl-terminated perfluoroalkylamine oxide surfactants
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The synthesis and usefulness in membrane biochemistry of a new class of surfactants have been investigated. 1-Ethyl-2-dimethylamine oxide polar heads were grafted onto a hydrocarbon, a fluorocarbon or an ethyl-capped fluorocarbon hydrophobic tail. The ability of the resulting surfactants to extract and/or to stabilize in aqueous solution a test membrane protein, cytochrome b6 f, was evaluated. While it is not a detergent, the hemifluorinated derivative efficiently kept purified cytochrome b6 f soluble, native and functional. The data suggest that alkyl-capped fluorocarbon surfactants provide an interesting alternative to classical detergents for handling membrane proteins in aqueous solutions under non-dissociating conditions.
- Chaudier, Yann,Zito, Francesca,Barthélémy, Philippe,Stroebel, David,Améduri, Bruno,Popot, Jean-Luc,Pucci, Bernard
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p. 1587 - 1590
(2007/10/03)
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- Separation of enantiomers by extraction based on lipase-catalyzed enantiomer-selective fluorous-phase labeling
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No chromatography is necessary to separate a racemic alcohol into its enantiomers. A highly fluorinated acyl residue was tranferred in an enantiomer-selective manner onto a racemic alcohol in the presence of a lipase [Eq. (1)]. The labeled enantiomer was separated from the unlabeled one by a simple but very efficient partition between fluorous and organic phases.
- Hungerhoff, Benno,Sonnenschein, Helmut,Theil, Fritz
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p. 2492 - 2494
(2007/10/03)
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- Synthese et polymerisation de monomeres fluores acryliques substitues en position α. Partie III. Synthese et polymerisation de l'α-heptadecafluoro-undecanoyloxyacrylate d'ethyle
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The synthesis of ethyl α-heptadecafluoro-undecanoyloxyacrylate (3), H2C=C(O-CO-CH2CH2C8F17)CO2CH2CH3, has been performed in three steps starting from ethyl bromopyruvate and heptadecafluoro-undecanoic acid, with an overall yield of c. 70percent.The homopolymerization and copolymerization of 3 have been easily carried out.From the kinetic study of homopolymerization and copolymerization of monomer 3 with styrene, kp2/kTe and r1, r2, the reactivity ratios of the two monomers, can be determined.
- Bessiere, J. M.,Boutevin, B.,El Bachiri, A.,El Harfi, A.
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- Synthesis and bioacceptability of fluorinated surfactants derived from F-alkylated tertiary amines
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Two methods for synthesizing tertiary F-alkylated amines are reported. The more general method allows the access in 56-87% yields to various N,N-dialkyl F-alkyl amines. These amines are key intermediates leading in 52-96% yields to several families of surfactants, including zwitterionic and cationic derivatives and amine oxides, potentially useful in the formulation of fluorocarbon emulsions for diagnostic and therapeutic uses. The toxicity of the new surfactants and the influence of the polar head were assessed: the long chain compounds (8, 9 and 10) were found to be toxic for cell cultures and the zwitterionic compounds (7b and 8) have a LD50 -1 in mice. The hemolysis test highlights the influence of the polar head: the zwitterionic compounds (7 and 8) were found to be non-hemolytic even at remarkably high concentrations (100 g l-1 for 8), whereas the cationic compounds 9 are highly hemolytic even at very low concentrations (0.05 g l-1).
- Nivet,Bernelin,Le Blanc,Riess
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p. 891 - 898
(2007/10/02)
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- Synthese des isocyanates de 2-F-alkylethyle
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Isocyanates are extremely important compounds in organic synthesis but their preparation is not always easy.One of the most convenient methods uses the acids as intermediates.In the F-alkyl series it is sometimes difficult to obtain them.We have optimized an efficient synthetic route to 2-F-alkylethyl isocyanates.
- Jouani, A. M.,Szoenyi, F.,Cambon, A.
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- Etude du comportement de benzoxazinones, substituees en position 2 par des groupements (per)halogenes, vis-a-vis de l'aniline
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This study describes firstly the synthesis of benzoxazinones substituted in position 2 by halogenated groups such as -(CH2)n-RF,Cl where n=0, 1 and 2 and RF,Cl is a perhalogenated group, and secondly the reaction of these new benzoxazinones with aniline in different media.Thus it is shown that the behaviour of trifluoromethyl-2-benzoxazinone towards aniline is different, in most cases, in comparison with benzoxazinones substituted by perfluorinated groups CnF2n+1 with n=2, 3 and 7.Under certain conditions (hot ethanol and aniline with triphenyl phosphite), it is observed that nucleophilic attack of aniline only occurs on the carbonyl group when benzoxazinones are substituted by an electron-withdrawing group such as C2F5, C3F7 and C7F15.
- Boutevin, B.,Rasoloarijao, L. Ranjalahy,Rouseau, A.,Garapon, J.,Sillion, B.
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- Synthesis of Perfluoroalkylated Xylitol Ethers and Esters: New Surfactants for Biomedical Uses
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New, well-defined surfactants and cosurfactants were synthesized with the objective of enhancing the stability of fluorocarbon emulsions destined to serve as oxygen carriers for biomedical applications.Monoperfluoroalkylated ethers of xylitol were achieved by addition of perfluoroalkyl iodide on the double bond of a protected xylitol allyl ether in a one-step addition-elimination reaction.Monoesters were obtained specifically on position 5 by treating 1,2:3,4-di-O-isopropylidenexylitol with perfluoroalkylated acid chlorides of various chain lengths in pyridine at room temperature.The products display strong surface activity and produce a remarkable synergistic stabilization of a fluorocarbon/Pluronic F-68 type emulsion.Biocompatibility data are reported, which include in vitro toxicity tests on Namalva cell cultures and hemolysis tests on human blood cells; the latter was found to decrease as the length of the F-alkyl chain increased.IV injection in mice (n=10) showed that these products were innocuous at 400-1000 mg/kg of body weight.Preliminary exchange-perfusion experiments on rats with an emulsion containing the F-octyl xylitol ether were encouraging.
- Zarif, Leila,Greiner, Jacques,Pace, Simonne,Riess, Jean G.
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p. 1262 - 1269
(2007/10/02)
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- PERFLUOROALKYLATED MONOESTERS OF 1,4-D-SORBITAN, ISOSORBIDE AND ISOMANNIDE: NEW SURFACTANTS FOR BIOMEDICAL APPLICATIONS
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A one step selective synthesis of pure 1,4-D-Sorbitan monoesters 4 was achieved by treating 1,4-D-Sorbitan 1 with RF9CH2)nCOCl (RF=C4F9, C5F11, C8F17; n=2, 10) in pyridine at room temperature. (13)C NMR establishes that esterification occured on carbon 6 only.While isomannide, 3, gives only one monoester, 8, the less symmetrical isosorbide 2 leads to two monoesters displaying significantly different physical properties.These compounds display moderate surface activities and do not perturb the growth and viability of Namalva lymphoblastold cell cultures.
- Zarif, Leila,Greiner, Jacques,Riess, Jean G.
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- New Surfactants for Biomedical Uses : F-alkylated Ethers and Esters of Galactose and Glucose
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Perfluoroalkylated ethers and esters derived from galactose and glucose have been synthesized, which constitute new non-ionic, well defined, monodisperse surfactants.Preliminary evaluation of their surface-active properties and biocompatibility is also reported.
- Manfredi, Alexandre,Abouhilale, Samir,Greiner, Jacques,Riess, Jean
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p. 872 - 878
(2007/10/02)
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