Claude Selve

Reduction d'azides en amines par le formiate d'ammonium par “Transfert d'Hydrogene Catalyse” (CTH)

Resume The azides are reduced to amines in very good yiels by “Catlytic Transfer Hydrogenation” (CTH) using ammonium formate.

Synthesis of homogeneous polyoxyethylene perfluorcalkyl surfactants: A new method

Abstract Polyoxyethylene perfluoroalkyl surfactants are synthesized from polyoxyethylene glycols using an appropriate intermediate monooxyphosphonium salt. In contrast with methods involving the polyaddition of ethylene oxide to a fluoroalcohol, the present procedure allows us to obtain surfactant molecules with a definite number of oxyethylene units, i.e. with a well-defined hydrophile lipophile balance (HLB). Fluorinated microemulsions could thus be prepared for the first time by mixing the surfactant of appropriate HLB to water and a fluorocarbon.

A Novel, Unequivocal Synthesis of Polyethylene Glycols

Abstract Unequivocal synthesis of polyethyleneglycols is presented. The key step for this synthesis is the selective monobenzylation of oligoethyleneglycols by the phase transfer catalysis technique.

Monodisperse perfluoro-polyethoxylated amphiphilic compounds with two-chain polar head - preparation and properties

Abstract Monodisperse new surfactant molecules -with a two-chain polyoxyethylene (EO) hydrophilic head and a perfluoroalkyl hydrophobic moiety linked together through an amide bond are synthesized by methods allowing large-scale production. Surface tension measurements (γ ~ 20 mN.m−1) show slow organization of the surfactant film at the water/air interface for longer fluorocarbon tail. Values of critical micellar concentrations and comparisons with monosubstituted amide surfactants are consistent with a high hydrophilicity of the amide function, a small influence of branching over hydrophilicity, and a hydrophobicity of each CF2 unit equivalent to 1.7 methylenes (in the analogous hydrogenated surfactants).

Nonionic amphiphilic compounds from aspartic and glutamic acids as structural mimics of lecithins

Monodisperse nonionic surfactant molecules, based on aspartic or glutamic acid, with two hydrogenated or fluorinated fatty amide chains in the hydrophobic part and one polyoxyethylene methoxy-capped chain (EOn−Me) in the hydrophilic head group have been synthesized. These compounds are structural mimics of natural lecithins. Their solubility in water or in formamide and the surface activities at 60°C have been measured and discussed in comparison with lecithin analogues that contained short chains. The compounds reported in this study showed physicochemical properties comparable with those of lecithins.

Nonionic amphiphilic compounds from lysine as molecular mimics of lecithins

New monodisperse nonionic surfactant molecules, based on lysine with two fatty acid chains in the hydrophobic part and one or two polyoxyethylene methoxycapped chains (EOn−Me) in the hydrophilic headgroup, are synthesized as mimics of natural lecithins. Their surface-activity properties indicate that these compounds have surfactant behavior whose global hydrophobic contribution is comparable to that of one fatty chain.

Synthese, proprietes complexantes et pouvoir extractant de β -diphosphoramides hydrophobes

Abstract New hydrophobic β-diphosphoramides of the type [( Me 2 N) 2 P(0)] 2 NR where R = hexyl(OHIPA), dodecyl(ODIPA) or benzyl (OBIPA) have been synthesized ; their hydrophobic character and their complexing and extracting abilities have been measured and compared to those of NIPA (R = methyl). It is shown that, among the four ligands, the compound ODIPA presents the best extracting properties because of its insolubility in water and its important complexing ability.

Synthetic porphyrins bearing a lateral peptide chain—V : On the lack of evidence from exafs for a short axial ZN-S bond in the case of cis-endo-3-propenamid-znTPP derivatives featuring a terminal S-alkyl cysteine residue

Abstract “Extended X-Ray Absorption Fine Structure” (EXAFS) spectroscopy has been used for probing the environment of the Zn2+ cation in three 3-propenamid-Zn tetraphenyporphyrin complexes. The lack of evidence for a short axial bond of the zinc atom to the sulfur atom of the cysteine terminal residue of the lateral peptidic chain is discussed, together with the few indications which suggest that a Zn-S interaction, if any, can only be weak and probably long range (4.1 A ?).

Réaction d'alcoolates sur les 2-perfluoroalkyl-éthanoate d'alkyle

Abstract The reaction of alcoholates with esters of perfluoroalkylethanoic acid ( I ) and 3-perfluoroalkyl-3-fluoro-propenoic acid ( II ) has been studied. Formation of ethers of the enol ester III or the acetal IV depends on the stoichiometric conditions used. The formation of the products proceeds via a Michael-type addition and elimination of fluoride ions from the enolate formed as an intermediate.

Amphiphilic and cation-complexing compounds based on peptidoamines

The synthesis of different types of amphiphilic compounds containing peptidoamine groups leads to surfactants with original properties such as the ability to coordinate metal ions. Water soluble acylcarcinine and alkylamidocarnosine surfactants are compared and the preparation of a silyloxyalkylamidocarnosine is described. The latter can be copolymerised with tetraalkoxysilanes to yield amphipathic organo-mineral solids that are also good ligands for metal cations.