Jean-Luc Couturier

Versatile One-Pot Synthesis of Supramolecular Plastics and Self-Healing Rubbers

We propose a strategy to obtain through a facile one-pot synthesis a large variety of supramolecular materials that can behave as differently as associating low-viscosity liquids, semicrystalline or amorphous thermoplastics, viscoelastic melts or rubbers. Such versatility is achieved thanks to simultaneous synthesis of branched backbones and grafting of associating units. This contrasts with usual synthetic pathways that rely on grafting functional groups on preprepared backbones. We use oligocondensation of fatty di- and triacids with diethylenetriamine and finely tune the molecular weight and degree of branching by end-capping some acid groups before condensation by reaction with aminoethylimidazolidone. Supramolecular assembly is formed thanks to complementary and self-complementary associations of amide, imidazolidone, and dialkylurea groups, and the stoichiometry directly controls the mesoscopic structure and properties.

Renewable materials as precursors of linear nitrile-acid derivatives via cross-metathesis of fatty esters and acids with acrylonitrile and fumaronitrile

The cross-metathesis of fatty acids and esters, as renewable raw materials, with acrylonitrile and fumaronitrile is presented. The cross-metathesis reactions of both terminal and internal double bond containing compounds were performed using a ruthenium catalyst and led to bifunctional nitrile-esters or nitrile-acids with high conversions. The tandem ruthenium catalysed cross-metathesis and hydrogenation provide precursors of aminoacid monomers for the production of polyamides from renewable resources.

Polyamide precursors from renewable 10-undecenenitrile and methyl acrylate via olefin cross-metathesis

The ruthenium-catalyzed cross-metathesis of the unsaturated fatty acid derivative 10-undecenenitrile 1 arising from castor oil with methyl acrylate produces a C12 nitrile ester with high turnover number. This product has potential as a new bio-sourced intermediate for the production of polyamides. This route competes favourably with the reverse cross-metathesis of methyl 10-undecenoate with acrylonitrile leading to the same C12 α,ω-amino ester 7 after hydrogenation of the carbon–carbon double bond and the nitrile functionality.

Ruthenium–Benzylidenes and Ruthenium–Indenylidenes as Efficient Catalysts for the Hydrogenation of Aliphatic Nitriles into Primary Amines

The catalytic reduction of alkyl nitriles into primary amines with ruthenium-benzylidene and ruthenium-indenylidene catalysts allowed the efficient hydrogenation of aliphatic nitrile esters that were derived from plant oils.

Hydroformylation of higher olefins by rhodium/tris((1H, 1H, 2H, 2H-perfluorodecyl)phenyl)phosphites complexes in a fluorocarbon/hydrocarbon biphasic medium: effects of fluorinated groups on the activity and stability of the catalytic system

Abstract The synthesis of three fluorous triarylphosphites in which an ‘insulating’ ethylene segment separates the perfluoroalkylgroup from the aryl group is described. The stabilities, solubilities and partition coefficients of these new compounds are reported. The complexes generated in situ from these fluorous triarylphosphites and Rh(acac)(CO)2 have been tested as catalysts for the hydroformylation of various olefins under fluorous biphasic conditions. The activities and the selectivities were found to vary markedly with the position of the perfluoroalkylgroup on the aromatic ring. The possibility to recover the catalytic system was also investigated from consecutive recycling experiments.

Palladium catalyzed telomerization of butadiene with water in a two phase system : drastic effect of the amine structure on the rate and selectivity

Abstract Telomerization of butadiene with water in the presence of carbon dioxide and a trialkylamine using a palladium-hydrosoluble phosphine system was investigated. 2,7-Octadien-1-ol was obtained as the main product, whilst 1,7-octadien-3-ol, octatrienes, 4-vinylcyclohexene and dioctadienyl ethers were formed as side products. The reaction was carried out exclusively in an aqueous-organic medium in the absence of solvent or co-solvent. The conversion and the selectivity are strongly dependent on the structure of trialkylamine. The role of the amine was discussed.

Highly efficient telomerization of butadiene into octadienol in a micellar system: a judicious choice of the phosphine/surfactant combination

Abstract Telomerization of butadiene into octadienols in a micellar system and in the presence of hydrophilic or hydrophobic phosphines derived from triphenylphosphine has been investigated. Activities and selectivities were strongly dependent on the steric properties of the phosphine and on the nature of the surfactant/phosphine couple. The best results have been obtained with the water-soluble phosphine/cationic surfactant combinations (octadienols selectivities > 70% and turnover frequencies up to 830 h −1 . The phosphine/anionic surfactant couples gave rise to octadienols in poor selectivities (40%) and activities (100 h −1 ). With the phosphine/neutral surfactant combinations, the results are strongly dependent on the nature of the phosphine. These results are interpreted from electrostatic interactions at the micelle-water interfaces.

Synthesis of highly labile SG1-based alkoxyamines under photochemical conditions.

Highly labile SG1-based alkoxyamines were synthesized using the photodecomposition of both azo compounds and dithiocarbamates. The former method was a straightforward procedure to obtain the alkoxyamines, but a high [azo]/[nitroxide] ratio is needed. The latter method required only a stoichiometric amount of dithiocarbamate and allowed the recovery of the disulfide after irradiation. This enabled combination of the two methods in a process where only 0.75 equiv of azo compound is needed and where sulfurous compounds acted only as intermediates.

Reactivity of ethanol over hydroxyapatite-based Ca-enriched catalysts with various carbonate contents

The Guerbet reaction of ethanol to produce heavier products was performed over a series of extensively characterized carbonate-containing hydroxyapatites (HAPs) with different Ca/P ratios and thus different densities, strengths and natures of acid and basic sites. These properties were correlated with the reactivity of the solids and an optimal ratio between the amount of acid and basic sites was evidenced (ca. 5). The best performance was accordingly obtained over the Hap-CO3 catalyst, which gave a yield of 30% of heavier alcohols at 40% ethanol conversion.

UNEXPECTED SYNTHESIS OF A NEW HIGHLY FLUOROCARBON SOLUBLE PHOSPHITE FOR BIPHASIC CATALYSIS

Abstract The synthesis of tris(4-(1-oxoperfluorooctyl)-2-perfluorooctylphenyl)phosphite and tris(2,4-bis(perfluorooctyl)phenyl)phosphite from commercially available 1-iodoperfluorooctane and 2,4-dibromophenol is described. The stability and the solubility of these new compounds are reported.