Base catalysed hydrogenation of methylbromooligosilanes with trialkylstannanes, identification of the first methylbromohydrogenoligosilanes
摘要:
The Lewis base catalysed hydrogenation of methylchlorooligsilanes with trialkylstannanes can also be applied to the hydrogenation of methylbromooligosilanes. In this way methylbromohydrogenoligosilanes were prepared for the first time. Methylbromotrisilanes with an > SiBrMe middle group (e.g. SiBrMe(2)-SiBrMe-SiBrMe(2)) are hydrogenated first at this silicon atom under formation of an > SiHMe group (e.g. SiBrMe(2)-SiHMe-SiBrMe(2)). Brominated silanes containing a quarternary Si(Si)(4) unit (e.g. Si(SiBrMe(2))(4)) do not react with trialkylstannanes.
Synthese und eigenschaften funktioneller polysilane: Die tetrasilane MeSi(SiMe2X)3 und hexasilane (Me2XSi)2MeSiSiMe(SiMe2X), X=Me, H, F, Cl, Br, I
作者:G. Kollegger、K. Hassler
DOI:10.1016/0022-328x(94)05010-9
日期:1995.1
Besides MeSi(SiMe(3))(3), the hexasilane [(Me(3)Si)(2)MeSi](2) is formed in astonishingly high yields in the reaction of a mixture of MeSiCl(3) and Me(3)SiCl with lithium, The permethylated silanes are easily functionalised with Me(3)SiCl/AlCl3, chlorinating all Me(3)Si-groups to form Me(2)ClSi. The reduction with LiAlH4 yields the Me(2)HSi-compounds, which are easily brominated and iodinated with CBr4 and HCI3. A subsequent reaction with ZnF2 gives the fluorocompounds. The Si-29-spectra, including (SiSi)-Si-29-Si-29 coupling constants, are reported and substituent effects are discussed.