Bernard Jousseaume

Reactifs de grignard vinyliques γ fonctionnels: I. Reactivite des organomagnesiens vis-a-vis d'alcools α acetyleniques en presence d'halogenures cuivreux☆

Abstract Primary α-acetylenic alcohols undergo regio- and stereo-specific additiions of Grignard reagents in the presence of cuprous halides. These reactions yield γ-functionally substituted vinylmagnesium compounds. With secondary and tertiary alcohols, the course of the reaction depends on the nature of alcohol and Grignard reagent.

A versatile access to unsymmetrical and symmetrical α-diketones via organotin reagents

Abstract Unsymmetrical α -diketones have been obtained via cross coupling of acyltins with acyl halides under PdCl2(PPh3)2 catalysis while symmetrical α -diketones have been readily obtained via “in situ” formation of acyltins using hexabutylditin and acyl chlorides under similar experimental conditions.

Tin dioxide thin films prepared from a new alkoxyfluorotin complex including a covalent SnF bond

Abstract Fluorine-doped tin dioxide (FTO) films were elaborated from a new Sn(IV) molecular precursor, the tert amyloxyfluorodipentan-2,4-dionatotin(IV) complex, to be used via the sol–gel route. Upon controlled hydrolysis in acetonitrile, a fluorinated polystannoxane was formed as a stable xerosol, which was characterized by multinuclear magnetic resonance and Mossbauer spectroscopies, elemental analysis, and thermogravimetry coupled to mass spectrometry. This xerosol was further dissolved in acetonitrile for depositing highly transparent films by the spin-coating and spray pyrolysis techniques. Film composition was determined by X-ray photoelectron spectroscopy, electron probe microanalysis and energy dispersive X-ray analysis. The F/Sn atomic ratio was 3% for spin-coated films and 10% for the sprayed films. A noticeable amount of carbon (C/Sn #10 at.%) was detected in the films whatever the deposition technique. In every case, the film resistivity was found to be larger than the one obtained from separate tin and fluorine precursors. This result was attributed to the excess of carbon and fluorine content in the oxide layers relieved from the xerosol.

Reactifs de grignard vinyliques γ fonctionnels : II. Iodolyse, alkylation et arylation des iodo-alcools

Abstract Iodination of γ-functionally substituted vinylic Grignard reagents, prepared by addition of organomagnesium compounds to α-aactylenic or α-allenic alcohols gives vinyl iodides stereospecifically. Treatment of these iodides with Grignard reagents in the presence of (PPh 3 ) 2 NiCl 2 gives allylic alcohols. This reaction proceeds with high stereoselectivity.

Hybrid organic-inorganic copolymers based on oxo-hydroxo organotin nanobuilding blocks

Hybrid organic-inorganic copolymers have been prepared following the nano-building blocks approach. The oxo-hydroxo butyltin macro-cation, (BuSn)12O14(OH)62+ , which is prepared by hydrolysis of butyltin tri-isopropoxide, is first functionalized by anchoring onto it methacrylate groups through electrostatic interactions. Then, to turn these isolated nano-building blocks into hybrid copolymers, they were assembled by initiating the organic polymerization of the methacrylate functions. 13 C and 119Sn NMR, in the solid state, and QELS evidences of the formation of hybrid organic-inorganic copolymers are reported.

Reactivite des organomagnesiens vis-a-vis de composes acetyleniques en presence du complexe de nickel (PPh3)2NiCl2

Abstract In the presence of dichlorobis(triphenylphosphine) nickel, acetylenic compounds undergo stereospecific or stereoselective syn addition of non recuding Grignard reagent. With reducing Grignard reagents, addition and reduction reactions are observed. These reactions yield vinylic organomagnesium compounds. A catalytic process is proposed to explain the experimental results.

Improved preparation of aliphatic propynoic esters

Abstract An improved procedure of esterification of propynoic acid, based on the N, N′-dicyclohexylcarbodiimide 4-dimethylaminopyridine condensation, is presented, which gives good results with primary, secondary, allylic and homoallylic alcohols. Reactions conditions are mild. Some limitations are given.

Reactions d'addition d'organomagnesiens aux alcools α-acetyleniques

Abstract Trans addition of several Grignard reagents to primary α-acetylenic alcohols with catalytic amount of CuI is reported. These reactions represent a new example of stereospecific synthesis of allylic alcohols.

Synthesis and Intramolecular Cyclisation of Gem Vinylic Di-Grignard Reagents

Continuing our studies of the reactions between Grignard reagents and functionally substituted alkynes (1) (2), we observed a regiospecific addition of organomagnesium compounds to metalated propar...

Investigations in the catalytic species of the distannoxane-catalyzed transcarbamoylation

1,3-Dihalodistannoxanes show a high activity as catalysts in transcarbamoylation, explained by the weak coordinative properties of the halogens, and act as Lewis acid and not alkoxide carriers in the catalytic cycle.