G. Merault

Silylation d'hydirocarbures acetyleniques au moyen de chlorosilanes

Abstract The action of the Me 3 SiCl/Mg/HMPT system on various acetylenic hydrocarbons leads by a new route, to mono-, di- or poly-silylated compounds. Most of the derivatives synthetized are new. The persilylation of phenylacetylerie led to a heptasilylated derivative with an unexpected structure, whereas the direct monosilylatmon, which leads to PhCCSiMe 3 , can be carried out in satisfactory yields.

Sulfonation de dérivés siliciés acétyléniques et alléniques fonctionnels

Abstract Sulfonating agents such as trimethylsilyl chlorosulfonate and “dioxane, SO 3 ”, react with silylalkynes (ΣCH 2 CCSiMe 3 ) in which Σ is a functional group, to yield silylacetylene sulfonates (Σ = OMe, Cl), acetylenic sulfates (Σ = OH, OSiMe 3 ) or SO 3 nitrogen adduct (Σ = NR 2 ). Allenoxysilanes Me 3 Si(Σ 1 )CCC(Σ 2 )OSiMe 3 yield either allenic sulfate (Σ 1 = Me 3 Si, Σ 2 = t-Bu) or silyl ketonic sulfonate (Σ 1 = n-Bu, Σ 2 = t-Bu). A mechanism is proposed for these reactions.

Silyation de derives carbonyles α,β-acetyleniques. Synthese d'allenoxysilanes

Abstract In the presence of magnesium and in hexamethylphosphoric triamide (HMPT), trimethylchlorosilane reacts with α,β-acetylenic ketones to give in most cases 1,4 addition of two trimethylsilyl groups to the conjugated system: allenoxysilanes, which constitute a new class of organometallic compounds, are formed. These upon hydrolysis give the corresponding silylated α,β-ethylenic ketones. Other reactions also take place: complete reduction of the carbonyl group giving polysilylated allenes; reductive duplication accompanied by O-silylation, and enolization. α,β-Acetylenic aldehydes give the same type of reactions.

Sulfonation de derives alleniques silicies. Synthese de composes sulfoniques insatures

Abstract Sulfonating agents such as trimethylsilylchlorosulfonate or “dioxan, SO3” adduct react with α-trimethylsilyl allenic compounds leading to an SO3 insertion on the unsaturated bond and produce silyl esters of sulfonic acids in good yields. In most experiments the sulfonating process led to the transposition of the allenic structure into an acetylenic or conjugated diene system. We have tried to explain such changes in the unsaturated skeleton by the electronic and steric effects of the other substituents to the allenic carbon atoms. As regards synthesis, such reactions have led to the discovery of new unsaturated sulfonic compounds which have not been studied before.

C-silylation de la méthylbuténone, de la carvone et de l'α-ionone par le systeme Me3SiCl/Li/THF

Abstract The reactions carried out by action of the Me3SiCl/Li/THF system on methylbutenone, carvone and α-ionone constitute the first examples of direct C-silylation from chlorosilane, of α-ethylenic ketones when the sequence is not complementarily conjugated.