Marcel Lefort

One-step regiospecific synthesis of allylic silanes - extension to benzylsilanes

Abstract Allyltrichlorosilanes are prepared according to a one-step regiospecific process based on the reaction of allyl chlorides with SiCl 4 and NiCp 2 /HMPA (catalyst), in the presence of industrial methylchlorodisilane fraction. 4 Benzyltrihalosilanes are similarly obtained.

Détermination de structures au moyen de la RMNn du 29Si: Transfert sélectif de population avec les méthylchlorodisilylméthanes

Abstract The selective population transfer (SPT) technique has been applied to 29 Si NMR of the complete series of methylchlorodisilylmethanes, several of which are new compounds. A great enhancement of the signals was observed and unambiguous assignments based on the determination of 2 J (SiH) coupling constants could be made. The first example of this type is presented.

Hydrogenolyse des disilanes issus de la synthese industrielle des methylchlorosilanes. Obtention de MeSiHCl2 et Me2SiHCl

Abstract The chlorodisilane residue from the industrial synthesis of methylchlorosilanes is cleaved under hydrogen (25 bars) in the presence of HMPT/nickelocene mixture or nickel (resulting from the reduction of dry NiCl 2 by Et 3 SiH) and leads to the formation of methyldichlorosilane (noble product), to the detriment of the methyltrichlorosilane (much less noble). This reaction also gives an appreciable amount of the rare and very useful dimethylchlorosilane.

An Efficient Synthesis of Alkylchlorosilanes from Alkenylchlorosianes

Abstract The use of a nickel catalyst (“Ni/SiH”) allows easy hydrogenation of alkenylchlorosilanes at atmospheric pressure, not affecting the chlorine function, and leads to quantitative synthesis of alkylchlorosilanes.

Nouvelles syntheses de Me2SiCl2 et Me3SiCl

Abstract Partial reduction of MeSiCl 3 and Me 2 SiCl 2 using CaH 2 or (TiH 2 ) n at high temperature (300°C) leads to MeSiHCl 2 and Me 2 SiHCl, respectively, in good yields but in low proportion. In the presence of AlCl 3 as catalyst the reaction affords Me 2 SiCl 2 and Me 3 SiCl, in yields higher than those previously observed in the absence of a reducing agent. These redistribution reactions involve MeSiHCl 2 and Me 2 SiHCl as intermediates. Consequently Me 2 SiHCl with or without Me 2 SiCl 2 and Alcl 3 deposited on carbon black as catalyst can undergo disproportionation to give Me 3 SiCl.