4342-64-7Relevant academic research and scientific papers
An Efficient Catalyst for the Conversion of Hydrosilanes to Alkoxysilanes
Lorenz, Catrin,Schubert, Ulrich
, p. 1267 - 1270 (2007/10/03)
The copper(I) hydride 6 is an efficient catalyst for the alcoholysis of primary and secondary silanes.The reactions proceed at room temperature within a few hours and give the alkoxysilanes in high yields.Only with bulky alcohols or silanes are longer reaction times and/or increased temperatures required.The presence of air accelarates the reactions and gives rise to higher yields of alkoxysilanes, particularly with bulky alcohols.Diols react with PhRSiH2 (R = Me, Ph) to afford 1,3-dioxo-2-silacycloalkanes and with tertiary silanes to furnish the bissilylated diols.When unsaturated alcohols (2-propen-1-ol or 2-propyn-1-ol) are employed, the double or triple bond is retained. - Keywords: Catalytic silane alcoholysis; Alkoxysilanes
Conversion of hydrosilanes to alkoxysilanes catalyzed by Cp2TiCl2/nBuLi
Bedard, Thomas C.,Corey, Joyce Y.
, p. 315 - 333 (2007/10/02)
The combination of Cp2TiCl2 and nBuLi provides an effective catalyst for alcoholysis of the model silanes n-HexSiH3, PhMeSiH2, Ph2SiH2 and PhMe2SiH by ethanol, isopropanol, t-butyl alcohol and phenol.Increasing the steric bulk of the substituents on either the alcohol or the silane generally requires longer reaction periods and/or increasing temperature.All SiH bonds are converted to SiOEt groups by ethanol and a single SiH bond in secondary silanes and two SiH bonds in tertiary silanes are replaced by t-butyl alcohol.Diols including pinacol, 2,4-pentanediol and 2,5-hexanediol react with PhRSiH2 (R = Me, Ph) to give 1,3-dioxa-2-silacyclopentanes, -hexanes and -heptanes, respectively.Attempts to form caged structures by condensation of primary silanes and triols was unsuccessful.Hydrolysis of PhRSiH2 is promoted by Cp2TiCl2/n-BuLi and the siloxane is produced in quantitative yield when R = Ph and a mixture of linear disiloxanes and trisiloxanes in addition to cyclopolysilanes are produced when R = Me.Other protic reagents including acids, mercaptans, amines and enolizable ketones did not react.The effects of reaction parameters such as temperature, silane to catalyst ratio, solvent, transition metal and replacements for nBuLi were also determined.
LE PROBLEME DE LA CONJUGAISON A TRAVERS UN ATOME DE SILICIUM ?-LIE DANS LES SYSTEMES SILA-2 BUTADIENIQUES
Bertrand, G.,Manuel, G.,Mazerolles, P.,Trinquier, G.
, p. 2875 - 2880 (2007/10/02)
The chemical behaviour of sila-2 butadienes, formed as transient intermediates either by thermolysis or by photolysis of various 1-vinylsilacyclobutanes, was studied with respect to hydroxylated compounds of different pKa values.Two mechanisms can explain the nature of the products obtained on the co-thermolysis of the cyclic compounds with phenol, one with 1-silacyclobut-1-ene intermediate and the other involving an allylic silicenium cation.In both hypothetical mechanisms, the 2-silabutadienes behave as a conjugated system since they lead either to cycloaddition or to (1,2)- and (1,4)-electrophilic addition.This evidence for a conjugation phenomenon through a silicon atom is supported by the calculation of the delocalisation energies of butadiene and 2-silabutadiene.
