Jean-François Pilard

Chemical synthesis at solid interfaces. On the use of conducting polythiophenes equipped of adequate linkers allowing a facile and highly selective cathodic SN bond scission with a fully regenerating resin process

Abstract Electrogenerated polythiophenes were evaluated as Merrifield-like resins for the anchoring of amine functions together with deprotection processes. Suitable linkers were terminated with a fully regenerable aromatic sulfonamide moiety. The SN bond was cleaved to liberate the amine with high selectivity under very mild conditions by cathodic means with amine liberation. Moreover a facile recycling process of the resin allows the further grafting of various amine functions.

Solid phase chemistry at a modified cathode surface. First synthesis of a polyamine precursor

Abstract The synthesis of a polyamine precursor was performed at a modified electrode interface. The chemical behaviour of the polythiophene matrix appeared identical to that of polystyrene beads. The target molecule, obtained with good yield, was released from the solid support by cathodic S–N bond scission, using the conducting properties of the polymer.

First synthesis of secondary P-alkenyl and P-alkynyl phosphine oxides

A general method for preparing secondary P-alkenyl and P-alkynyl phosphine oxides, compounds unknown so far, involves the condensation of the vinyl Grignard reagent or lithium acetylide on P-chloroaminophosphines followed by acidic hydrolysis of the corresponding vinyl- or ethynylaminophosphines on a solid acid (Amberlyst 15). The few reported chemical properties are mainly related to the strong PH bond activation. Of special interest is the addition of a secondary vinylphosphine oxyde derivative on methyl acrylate which occurs at room temperature without any catalyst.

Synthesis and electrochemical behaviour of new polythiophenes branched with sulfonamides for solid phase synthesis

The synthesis of thiophenes 3-substituted by arylsulfonamide groups is described. Their electropolymerization and the characteristics of the polymers thus formed were studied, showing the importance of the nature of the spacer intercalated between the thiophene unit and the electroactive cleavable aromatic function under electron transfer. The presence of an oxygen atom in an appropriate position in the chain appears to dramatically control the electrochemical stability and the electroactivity of the polymer.

Synthesis and electrochemistry of a novel polyfluorenylidene containing ferrocene units

A novel fluorenylidene containing a ferrocene unit has been electropolymerized. In this polymer, the ferrocene unit is grafted to the main polyfluorenylidene chain as a pendant group. The polymer is electroactive in non-aqueous and aqueous media.

Chiral auxiliaries onto conducting polymers

Abstract The synthesis of new chiral auxiliaries was performed onto conducting polythiophene. The electrochemical behaviour of such a matrix was investigated and one of them present a noticeable stability when an adequate spacer is introduced between the redox centre and the chiral unit.

Substituted Dihydrophosphinines, Synthesis and Base-Induced Isomerisation

Abstract The synthesis of α-chloro-tetrahydrophosphinines by inter- or intramolecular [4+2] cycloaddition reactions involving unstabilized phosphaalkenes is presented. Conditions for a selective base-induced isomerisation of substituted dihydrophosphinines are precised. A tautomeric phosphaalkene/vinylphosphine equilibrium was for the first time evidenced.

The cathodic cleavage of the SP bond. Synthesis and electrochemical behaviour of sulfonamide phosphorus analogues

Abstract P-diphenylarylsulfophosphamides can be obtained by condensation of Ph 2 PLi on various arylsulfonyl chlorides. These sulfonamide phosphorus analogues exhibit facile cathodic cleavage reaction yielding, after quenching, diphenylphosphinic acid and aryl sulfide.

1,4-Bis(alkylsulfonyl)benzenes. A new and unexpected cathodic cleavage leading to the corresponding phenoxy ions

Abstract 1,4-Bis(alkylsulfonyl)benzenes 2 exhibit the formation of a fairly stable anion radical under cathodic electron transfer. Its fragmentation leads both to 1-alkylsulfonyl-4-alkyl benzenes ( ipso substitution) and 4-alkylsulfonylphenoxy ions, the presence of the latter suggesting a new mode of cleavage for strongly activated sulfones.

Poly (3-substituted) thiophenes electroactive in water

Three thiophene rings bearing n-ethoxy arylsulfonamide pendant groups were synthesized and their electropolymerization was performed at a platinum electrode. The electrochemical behaviour of the polythiophene matrix was studied both in organic and in aqueous solvent. If all polymers present a reversible n- and p-doping process in organic solvents, only one of them particularly possess a reversible p-doping in aqueous media. This phenomenon was shown to be directly related to the nature of the spacer between the thiophene ring and the aryl sulfonamide unit.