75-79-6Relevant articles and documents
Unexpected disproportionation of tetramethylethylenediamine-supported perchlorodisilane Cl3SiSiCl3
Tillmann, Jan,Meyer-Wegner, Frank,Nadj, Andor,Becker-Baldus, Johanna,Sinke, Tanja,Bolte, Michael,Holthausen, Max C.,Wagner, Matthias,Lerner, Hans-Wolfram
, p. 8599 - 8606 (2012)
The addition compound Cl3SiSiCl3·TMEDA was formed quantitatively by treatment of Cl3SiSiCl3 with tetramethylethylenediamine (TMEDA) in pentane at room temperature. The crystal structure of Cl3SiSiCl3·TMEDA displays one tetrahedrally and one octahedrally bonded Si atom (monoclinic, P2 1/n). 29Si CP/MAS NMR spectroscopy confirms this structure. Density functional theory (DFT) calculations have shown that the structure of the meridional isomer of Cl3SiSiCl3· TMEDA is 6.3 kcal lower in energy than that of facial coordinate species. Dissolving of Cl3SiSiCl3·TMEDA in CH 2Cl2 resulted in an immediate reaction by which oligochlorosilanes SinCl2n (n = 4, 6, 8, 10; precipitate) and the Cl--complexed dianions [SinCl2n+2] 2- (n = 6, 8, 10, 12; CH2Cl2 extract) were formed. The constitutions of these compounds were confirmed by MALDI mass spectrometry. Additionally, single crystals of [Me3NCH 2CH2NMe2]2[Si6Cl 14] and [Me3NCH2CH2NMe 2]2[Si8Cl18] were obtained from the CH2Cl2 extract. We found that Cl3SiSiCl 3·TMEDA reacts with MeCl, forming MeSiCl3 and the products that had been formed in the reaction of Cl3SiSiCl 3·TMEDA with CH2Cl2. X-ray structure analysis indicates that the structures of [Me3NCH2CH 2NMe2]2[Si6Cl14] (monoclinic, P21/n) and [Me3NCH2CH 2NMe2]2[Si8Cl18] (monoclinic, P21/n) contain dianions adopting an "inverse sandwich" structure with inverse polarity and [Me3NCH 2CH2NMe2]+ as countercations. Single crystals of SiCl4·TMEDA (monoclinic, Cc) could be isolated by thermolysis reaction of Cl3SiSiCl3·TMEDA (50 °C) in tetrahydrofuran (THF).
METHOD FOR THE DEHYDROGENATION OF DICHLOROSILANE
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Paragraph 0091, (2021/06/22)
Dichlorosilane and trichlorosilane are dehydrogenated at elevated temperature in the presence of an ammonium or phosphonium salt as a catalyst, and a halogenated hydrocarbon or hydrogen halide. The method may be used to synthesize organochlorosilane.
A General and Selective Synthesis of Methylmonochlorosilanes from Di-, Tri-, and Tetrachlorosilanes
Naganawa, Yuki,Nakajima, Yumiko,Sakamoto, Kei
supporting information, p. 601 - 606 (2021/01/13)
Direct catalytic transformation of chlorosilanes into organosilicon compounds remains challenging due to difficulty in cleaving the strong Si-Cl bond(s). We herein report the palladium-catalyzed cross-coupling reaction of chlorosilanes with organoaluminum reagents. A combination of [Pd(C3H5)Cl]2 and DavePhos ligand catalyzed the selective methylation of various dichlorosilanes 1, trichlorosilanes 5, and tetrachlorosilane 6 to give the corresponding monochlorosilanes.
Method for preparing methylchlorosilanes
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Paragraph 0040-0056, (2020/10/29)
The present invention relates to a method for producing methylchlorosilane by a direct synthesis method and, more specifically, to a method for preparing dimethyldichlorosilane with an improved output of methylchlorosilane (M2) and trimethylchlorosilane (M3). According to the present invention, the method for preparing methylchlorosilane comprises the step of reacting a contact composition including metal silicon, aluminum, a catalyst and a cocatalyst with methyl chloride, wherein the contact composition includes 0.1 to 0.2 parts by weight based on 100 parts by weight of metal silicon.(AA) MCS+ECM+Unreacted MC(BB) ECM+Unreacted MC(CC) FBR(MCS Reactor)(DD) ECM(By-product)(EE) Unreacted MCCOPYRIGHT KIPO 2021
Synthesis of Functional Monosilanes by Disilane Cleavage with Phosphonium Chlorides
Santowski, Tobias,Sturm, Alexander G.,Lewis, Kenrick M.,Felder, Thorsten,Holthausen, Max C.,Auner, Norbert
supporting information, p. 3809 - 3815 (2019/02/13)
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.
CLEAVAGE OF METHYLDISILANES, CARBODISILANES AND METHYLOLIGOSILANES WITH ALKALI-AND ALKALINE EARTH METAL SALTS
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Page/Page column 55, (2019/04/16)
The invention relates to a process for the manufacture of methylmonosilanes comprising the step of subjecting one or more methyldisilanes, one or more methyloligosilanes, one or more carbodisilanes, or mixtures thereof to cleavage conditions resulting in the cleavage of silicon- silicon bonds or silicon-carbon bonds in carbodisilanes, and optionally a step of separating the resulting methylmonosilanes.
Disilane Cleavage with Selected Alkali and Alkaline Earth Metal Salts
Santowski, Tobias,Sturm, Alexander G.,Lewis, Kenrick M.,Felder, Thorsten,Holthausen, Max C.,Auner, Norbert
supporting information, p. 13202 - 13207 (2019/10/22)
The industry-scale production of methylchloromonosilanes in the Müller–Rochow Direct Process is accompanied by the formation of a residue, the direct process residue (DPR), comprised of disilanes MenSi2Cl6-n (n=1–6). Great research efforts have been devoted to the recycling of these disilanes into monosilanes to allow reintroduction into the siloxane production chain. In this work, disilane cleavage by using alkali and alkaline earth metal salts is reported. The reaction with metal hydrides, in particular lithium hydride (LiH), leads to efficient reduction of chlorine containing disilanes but also induces disproportionation into mono- and oligosilanes. Alkali and alkaline earth chlorides, formed in the course of the reduction, specifically induce disproportionation of highly chlorinated disilanes, whereas highly methylated disilanes (n>3) remain unreacted. Nearly quantitative DPR conversion into monosilanes was achieved by using concentrated HCl/ether solutions in the presence of lithium chloride.
Neutral-Eosin-Y-Photocatalyzed Silane Chlorination Using Dichloromethane
Fan, Xuanzi,Xiao, Pin,Jiao, Zeqing,Yang, Tingting,Dai, Xiaojuan,Xu, Wengang,Tan, Jin Da,Cui, Ganglong,Su, Hongmei,Fang, Weihai,Wu, Jie
supporting information, p. 12580 - 12584 (2019/08/16)
Chlorosilanes are versatile reagents in organic synthesis and material science. A mild pathway is now reported for the quantitative conversion of hydrosilanes to silyl chlorides under visible-light irradiation using neutral eosin Y as a hydrogen-atom-transfer photocatalyst and dichloromethane as a chlorinating agent. Stepwise chlorination of di- and trihydrosilanes was achieved in a highly selective fashion assisted by continuous-flow micro-tubing reactors. The ability to access silyl radicals using photocatalytic Si?H activation promoted by eosin Y offers new perspectives for the synthesis of valuable silicon reagents in a convenient and green manner.
PROCESS FOR THE PRODUCTION OF ORGANOHYDRIDOCHLOROSILANES FROM HYDRIDOSILANES
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Page/Page column 40; 41; 42, (2019/04/16)
The invention relates to a process for the manufacture of organomonosilanes bearing both hydrogen and chlorine substituents at the silicon atom by subjecting one or more organomonosilanes to the reaction with one or more di- or carbodisilanes in the presence of one or more compounds (C) acting as a redistribution catalyst, wherein at least one of the silanes has only hydrogen and organic residues at the silicon atoms.
Exhaustively Trichlorosilylated C1 and C2 Building Blocks: Beyond the Müller-Rochow Direct Process
Georg, Isabelle,Teichmann, Julian,Bursch, Markus,Tillmann, Jan,Endeward, Burkhard,Bolte, Michael,Lerner, Hans-Wolfram,Grimme, Stefan,Wagner, Matthias
supporting information, p. 9696 - 9708 (2018/07/21)
The Cl--induced heterolysis of the Si-Si bond in Si2Cl6 generates an [SiCl3]- ion as reactive intermediate. When carried out in the presence of CCl4 or Cl2C=CCl2 (CH2Cl2 solutions, room temperature or below), the reaction furnishes the monocarbanion [C(SiCl3)3]- ([A]- 92%) or the vicinal dianion [(Cl3Si)2C-C(SiCl3)2]2- ([B]2- 85%) in excellent yields. Starting from [B]2-, the tetrasilylethane (Cl3Si)2(H)C-C(H)(SiCl3)2 (H2B) and the tetrasilylethene (Cl3Si)2C=C(SiCl3)2 (B; 96%) are readily available through protonation (CF3SO3H) or oxidation (CuCl2), respectively. Equimolar mixtures of H2B/[B]2- or B/[B]2- quantitatively produce 2 equiv of the monoanion [HB]- or the blue radical anion [B?]-, respectively. Treatment of B with Cl- ions in the presence of CuCl2 furnishes the disilylethyne Cl3SiC≡CSiCl3 (C; 80%); in the presence of [HMe3N]Cl, the trisilylethene (Cl3Si)2C=C(H)SiCl3 (D; 72%) is obtained. Alkyne C undergoes a [4+2]-cycloaddition reaction with 2,3-dimethyl-1,3-butadiene (CH2Cl2, 50 °C, 3d) and thus provides access to 1,2-bis(trichlorosilyl)-4,5-dimethylbenzene (E1; 80%) after oxidation with DDQ. The corresponding 1,2-bis(trichlorosilyl)-3,4,5,6-tetraphenylbenzene (E2; 83%) was prepared from C and 2,3,4,5-tetraphenyl-2,4-cyclopentadien-1-one under CO extrusion at elevated temperatures (CH2Cl2, 180 °C, 4 d). All closed-shell products were characterized by 1H, 13C{1H}, and 29Si NMR spectroscopy; an EPR spectrum of [nBu4N][B?] was recorded. The molecular structures of [nBu4N][A], [nBu4N]2[B], B, E1, and E2 were further confirmed by single-crystal X-ray diffraction. On the basis of detailed experimental investigations, augmented by quantum-chemical calculations, plausible reaction mechanisms for the formation of [A]-, [B]2-, C, and D are postulated.
