- METHOD FOR PRODUCING ORGANOSILICON COMPOUND USING HALOSILANE AS RAW MATERIAL
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PROBLEM TO BE SOLVED: To provide a novel method for producing an organosilicon compound. SOLUTION: The method for producing an organosilicon compound includes a reaction step (I) of reacting a halosilane represented by formula (a) with a compound containing a hydrocarbon group represented by formula (b) in the presence of an organic base to generate an organosilicon compound represented by formula (c). (In the formula (I), n is an integer of 0-3; each R1 independently represents a hydrogen atom or a C1-20 hydrocarbon group which may contain a heteroatom; X represents a bromo group (-Br) or a chloro group (-Cl); and R2 represents a compound containing a hydrocarbon group.) SELECTED DRAWING: Figure 1 COPYRIGHT: (C)2020,JPOandINPIT
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Paragraph 0044-0045; 0055
(2019/12/10)
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- Building blocks for oligomeric siloxanes –selective chlorination of hydrido-siloxanes
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A new method was developed to achieve highly selective monochlorination of α,ω-dihydridosiloxanes, ((H)Me2SiO-(SiMe2O)n-SiMe2(H), n = 0–2; (H)R2Si–O-SiR2(H); R = Me, iPr, Ph; 3,5-dihydridooctamethyltetrasiloxane, Me3SiO-(Si(H)MeO)2–SiMe3) with trichloroisocyanuric acid (TCCA). The dependence of the selectivity of the monochlorination on the siloxane chain length is also discussed.
- Hafner, Thomas,Torvisco, Ana,Uhlig, Frank
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supporting information
p. 1 - 4
(2018/09/11)
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- B(C6F5)3-Catalyzed Selective Chlorination of Hydrosilanes
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The chlorination of Si?H bonds often requires stoichiometric amounts of metal salts in conjunction with hazardous reagents, such as tin chlorides, Cl2, and CCl4. The catalytic chlorination of silanes often involves the use of expensive transition-metal catalysts. By a new simple, selective, and highly efficient catalytic metal-free method for the chlorination of Si?H bonds, mono-, di-, and trihydrosilanes were selectively chlorinated in the presence of a catalytic amount of B(C6F5)3 or Et2O?B(C6F5)3 and HCl with the release of H2 as a by-product. The hydrides in di- and trihydrosilanes could be selectively chlorinated by HCl in a stepwise manner when Et2O?B(C6F5)3 was used as the catalyst. A mechanism is proposed for these catalytic chlorination reactions on the basis of competition experiments and density functional theory (DFT) calculations.
- Chulsky, Karina,Dobrovetsky, Roman
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supporting information
p. 4744 - 4748
(2017/04/11)
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- Utility of trichloroisocyanuric acid in the efficient chlorination of silicon hydrides
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The potential of trichloroisocyanuric acid (TCCA) as a chlorination agent for efficient conversion of Si-H functional silanes and siloxanes to the corresponding Si-Cl functional moieties was explored. In comparison to methods using other chlorinating agents, TCCA is inexpensive, results in a much faster reaction and produces a high purity product with a conversion that is essentially quantitative. A variety of chloro derivatives of linear and cyclic structures have been synthesized from silicon hydrides using this reagent with impressive yields that typically exceed 90%: PhSiCl3 (97.5%); PhMeSiCl2 (95.5%); Ph3SiCl (97.5%); Vi3SiCl (98.7%); (EtO)3SiCl (99.7%); t-Bu3SiCl (～100%); (MeClSiO)4 (86.5%); (MeClSiO)5 (95%); (MeClSiO)7 (96.5%); Ph(OEt)2SiCl (98%); ClMe2SiOSiMe2Cl (98.6%); ClMe2SiOSiMeClOSiMe2Cl (94.6%); ClMe2Si(OSiMeCl)2OSiMe2C l (92.3%); (Me3SiO)3SiCl (97%); Me3SiOSiClPhOSiMe3 (99%); Me3SiO(SiMeClO)3SiMe3 (95.7%); ClSi(OSiMe3)2OSi(OSiMe3) 2Cl (93.6%). For monohydridosilanes, dichloromethane (CH2Cl2) was a suitable solvent in which nearly quantitative conversion was observed within several minutes following the addition of the silanes to TCCA. For certain cyclic and linear siloxanes, and especially silanes containing multiple hydrogen atoms on the same silicon for which the reaction is sluggish in CH2Cl2, tetrahydrofuran (THF) was the preferred solvent. For a sterically demanding silane that did not undergo chlorination even in THF viz., HSi(OSiMe3)2O-Si(OSiMe3)2H, 1,2-dichloroethane was the best solvent.
- Varaprath, Sudarsanan,Stutts, Debra H.
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p. 1892 - 1897
(2007/10/03)
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- Catalytic reactions of hydrosiloxanes with allyl chloride
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Catalytic reactivity of Si-H bond of di-, trisiloxanes with allyl chloride in the presence of platinum catalyst has been examined. Hydrosilylation process competes with hydrogen substitution by chlorine and/or propenyl group. The effect of the reaction conditions as well as structure of siloxane on the yield and selectivity of the number of products has been discussed. Several consecutive-competitive processes have been identified. The results obtained can be helpful in the study of the catalytic hydropolysiloxanes reactions with allyl derivatives-systems of great practical importance, to produce commercial functionalized silicones.
- Jankowiak, Marcin,MacIejewski, Hieronim,Gulinski, Jacek
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p. 4478 - 4487
(2007/10/03)
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- Lanthanocene (Ln = PrIII, YbIII) chlorides involving tetramethyldisiloxane-interlinked cyclopentadienyl ligands
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Two new lanthanocenophanes PrIIICl*THF>x (2; x=1 or 2) and YbIIICl>2 (3), were made from LnCl3 (Ln=Pr or Yb) and K2 in THF.The 1H NMR spectra of THF-d8 solutions of paramagnetic 2 (at +35 to -25 deg C) and 3 (at 8 (at > 10 deg C), respectively, display somewhat less complex 1H NMR spectra consistent with a virtually symmetrical position of the Me2SiOSiMe2 unit with respect to the cent-Ln-cent' plane (cent = C5H4Si centroid).A low temperature (-100 deg C) single-crystal X-ray study of 3 has confirmed the presence of centrosymmetric, Cl-bridged dimers in which the molecular configuration of the mononuclear YbIIICl2 units correspond to that of the previously described complex IVCl2> (1).The high-resolution mass spectrum of 3 displays several signals from dinuclear fragments, the B/E-linked scans of which suggest, inter alia, intramolecular reorientation of at least one O(Me2SiC5H4)2 ligand from the chelating into a metal-bridging position.Key words: Ytterbium; Praseodymium; Metallocenes; Lanthanides; Chiral metallocenophanes; Crystal structure
- Graeper, Jens,Fischer, R. Dieter,Paolucci, Gino
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- Synthesis of siloxanes. XII. Cleavage of siloxanes by hydrogen chloride
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1H NMR spectroscopy has been used in a kinetic study of the cleavage of siloxane bonds by hydrogen chloride in dioxane.The cleavages show an induction period which is associated with the autocatalytic effect of the water formed during the reaction.The kinetic behavior can be expressed in terms of a rate law that includes rate constants for cleavage by both dioxane*HCl (k1) and H2O*HCl (k2).The k'1 (k'1 = k1*-4) and k'2 (k'2 = k2*-3) values correlate with ?* values; thus ρ* values of -1.4 and -0.7 were obtained for k'1 and k'2, respectively.The ?* value of 0.35 that we previously derived for the Me3SiO group applies in this reaction.The reaction of 1,3-bis(p-methoxyphenyl)tetramethyldisiloxane with hydrogen chloride involves cleavage of silicon-aryl rather than Si-O bonds.
- Scheim, U.,Lehnert, R.,Porzel, A.,Ruehlmann, K.
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p. 141 - 150
(2007/10/02)
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