- DISILANE-, CARBODISILANE-AND OLIGOSILANE CLEAVAGE WITH CLEAVAGE COMPOUND ACTING AS CATALYST AND HYDROGENATION SOURCE
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The invention relates to a process for the manufacture of monosilanes of formula (I): MexSiHyClz (I), comprising: the step of subjecting a silane substrate (methyldisilanes, methyloligosilanes, or carbodisilanes) to a cleavage reaction of the silicon-silicon bond(s) or the silicon- carbon bonds in silane substrates the reaction involving a cleavage compound selected from a quaternary Group 15 onium compound R4 QX, a heterocyclic amine, a heterocyclic ammonium halide, or a mixture of R3P and RX. The starting material disilanes to be cleaved has the formula (II): MemSi2HnClo (II) The starting material oligosilanes to be cleaved have the general formula (III): MepSiqHrCIs (II I), The starting material carbodisilanes to be cleaved have the general formula (IV): (MeaSiHbCle)-CH2-(MecSiHdClf) (IV)
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Page/Page column 47
(2019/04/16)
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- Synthesis of Functional Monosilanes by Disilane Cleavage with Phosphonium Chlorides
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The Müller–Rochow direct process (DP) for the large-scale production of methylchlorosilanes MenSiCl4?n (n=1–3) generates a disilane residue (MenSi2Cl6?n, n=1–6, DPR) in thousands of tons annually. This report is on methylchlorodisilane cleavage reactions with use of phosphonium chlorides as the cleavage catalysts and reaction partners to preferably obtain bifunctional monosilanes MexSiHyClz (x=2, y=z=1; x,y=1, z=2; x=z=1, y=2). Product formation is controlled by the reaction temperature, the amount of phosphonium chloride employed, the choice of substituents at the phosphorus atom, and optionally by the presence of hydrogen chloride, dissolved in ethers, in the reaction mixture. Replacement of chloro by hydrido substituents at the disilane backbone strongly increases the overall efficiency of disilane cleavage, which allows nearly quantitative silane monomer formation under comparably moderate conditions. This efficient workup of the DPR thus not only increases the economic value of the DP, but also minimizes environmental pollution.
- Santowski, Tobias,Sturm, Alexander G.,Lewis, Kenrick M.,Felder, Thorsten,Holthausen, Max C.,Auner, Norbert
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supporting information
p. 3809 - 3815
(2019/02/13)
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- Synthesis of silicon-functionalized (silylmethyl)silanes and-dichlorocarbosilanes using the TMOP (2,4,6-trimethoxyphenyl) protecting group: (TMOP)Me2SiCH2Cl and (TMOP) 2MeSiCH2Cl as reagents to introduce the ClMe 2SiCH2, MeOMe2SiCH2, or Cl2MeSiCH2 group by nucleophilic substitution at silicon
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In this study, the synthetic potential of the 2,4,6-trimethoxyphenyl (TMOP)-substituted (chloromethyl)silanes (TMOP)Me2SiCH2Cl (1) and (TMOP)2MeSiCH2Cl (2) for the preparation of Si-functionalized (silylmethyl)silanes and α,ω-dichlorocarbosilanes (with skeletons consisting of alternate carbon and silicon atoms) was investigated. Compounds 1 and 2 were used as reagents to introduce the ClMe 2SiCH2, MeOMe2SiCH2, or Cl 2MeSiCH2 group by nucleophilic substitution at silicon. The three-step synthetic method involves the (i) transformation of 1 and 2 into (TMOP)Me2SiCH2MgCl, (TMOP)Me2SiCH 2Li, (TMOP)2MeSiCH2MgCl, and (TMOP) 2MeSiCH2Li, respectively, (ii) reaction of these nucleophiles with chloro- or methoxysilanes, and (iii) subsequent selective cleavage of the TMOP protecting group with HCl/Et2O or MeOH/[CF 3COOH]. Using this method, the following compounds were prepared: ClMe2SiCH2SiMe3 (3), ClMe2SiCH 2SiMe2Cl (4), ClMe2SiCH2SiMeCl 2 (5), ClMe2SiCH2SiCl3 (6), ClMe2SiCH2Si(OMe)3 (7), MeOMe 2SiCH2Si(OMe)3 (8), Cl2MeSiCH 2SiMe3 (9), Me2Si(CH2SiMe 2Cl)2 (10), and Me2Si(CH2SiMe 2CH2SiMe2Cl)2 (11).
- Laskowski, Nadine,Reis, Eva-Maria,Koetzner, Lisa,Baus, Johannes A.,Burschka, Christian,Tacke, Reinhold
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p. 3269 - 3278
(2013/07/27)
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- New chalcogen derivatives of silicon possessing adamantane and noradamantane structures
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The reaction of Si2Cl4Me2 (1) with Li2Se in THF yields exclusively the noradamantane (MeSi)4Se5 (4). The sulfur analogue (MeSi)4S5 (3) could be obtained from 1, MeSiCl
- Herzog,Rheinwald
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p. 133 - 143
(2007/10/03)
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