Jean-Georges Duboudin

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.

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.

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.

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...

Sulfones organostanniques: synthese et reactivite des trialkystannyl-1 para-toluenesulfonyl-2 acetylenes

Abstract The preparation and some reactions of 1- para -toluenesulfonyl-2-(trialkylstannyl)acetylenes are desribed. The compounds undergo addition to a number of conjugated dienes, whereas ene adducts, owing to low enophilic reactivity cannot generally be obtained. Desulfonylation reactions give rise to a variety of vinyltin derivatives.

Reactifs de Grignard vinyliques γ fonctionnels : III. Addition a quelques derives carbonyles

Abstract Δtα,β-Butenolides can be obtained by carbonation of γ-functionally substituted vinylic Grignard reagents, prepared by addition of organomagnesium compounds to α-acetylenic or α-allenic alcohols. By addition to aldehydes and ketones, these vinylic Grignard reagents yield diols, which give unsaturated ethers by cyclization reactions.

Etude des reactions des reactifs de grignard allyliques vis a vis du benzyne et du cyclohexyne

Abstract In the presence of benzyne, allylic Grignard reagents undergo three competitive reactions: nucleophilic addition and (π 2 + π 2 ) and (π 4 + π 2 ) cycloadditions. The influence of substituents in the Grignard reagents on the course of the reaction is discussed. With cyclohexyne, only nucleophilic addition is observed.

Isomerisation thermique des bromures de diphenyl-1,2 propenylmagnesium-1 (E) et (Z) en presence de complexes du nickel

Abstract The thermal isomerization of the pair of title isomers by nickel complexes is explained by the intermediacy of π-allylic nickel derivatives.

Synthese et etude par RMN 119Sn de nouveaux composes benzyliques organostanniques

Abstract Preparations of new benzylic organotin compounds are presented. 119 Sn NMR studies show long range coupling constants 119 Sn 119 Sn and intramolecular coordination of tin.