Sila-pheromones: Silicon analogues of the female sex pheromone of the processionary moth Thaumetopoea pityocampa
The 15- and 10-dimethylsila-analogues of (Z)-13-hexadecen-11-ynyl acetate, the main component of the female sex pheromone of the processionary moth Thaumetopoea pityocampa, were synthesized to evaluate the influence of the silicon atom on the biological activity.
Synthesis and Spectroscopic Characterization of Di- and Trisilylethenes
Di- and trisilylethenes have been prepared by catalytic hydrosilylation of trimethylsilyl-, bis(trimethylsilyl)- and bis(trichlorosilyl)ethyne and converted into the hydrogenated derivatives by LiAlH4-reduction.The stereochemistry of the products and the effects of substitution of methyl vs. chlorine ligands on the NMR coupling constants J(29Si/1H) have been investigated by analysis of selectively (Me)-decoupled 29Si NMR spectra.From the results it has been concluded, that the catalytic hydrosilylation of silylated ethynes proceeds in a stereospecific syn fashion yield ing trans adducts.Substitution of methyl by chlorine at one or two Si-atoms in tris(trimethylsilyl)ethene leads to an increase of the coupling constant J(29Si/1H vinyl) with the chlorinated Si-atoms and reduces the values for those Si-atoms, where the methyl groups are retained. - Keywords: Di- and Trisilylethenes, Catalytic Hydrosilylation
Schmidbaur, H.,Ebenhoech, J.
p. 1543 - 1548
(2007/10/02)
UNUSUAL REGIOSELECTIVE HYDROSILYLATION OF ETHYNYLMETHYLDICHLOROSILANE WITH DIMETHYILCHLOROSILANE CATALYZED BY TETRAKIS(TRIPHENYLPHOSPHINE)PLATINUM(O)
The hydrosilylation of ethynylmethyldichlorosilane with dimethylchlorosilane catalyzed by tetrakis(triphenylphosphine)platinum(O) was found to show quite an unusual regioselectivity to afford the geminal product, 1-(methyldichlorosilyl)-1-(dimethylchlorosilyl)ethene, almost exclusively.
ADDITION OF CHLORODISILANES TO ACETYLENE CATALYZED BY TETRAKIS(TRIPHENYLPHOSPHINE)PALLADIUM(0). A FACILE ROUTE TO (Z)-1,2-BIS(CHLOROSILYL)ETHENES
In the presence of a catalytic amount of tetrakis(triphenylphosphine)palladium(0), chlorodisilanes of type MenSi2Cl6-n (n=2-5) add to acetylene to afford 1,2-bis(chlorosilyl)ethenes in reasonable yields.