- METHOD OF PREPARING HALOGENATED SILAHYDROCARBYLENES
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A method comprises separate and consecutive steps (i) and (ii). Step (i) includes contacting a copper catalyst with hydrogen gas and a halogenated silane monomer at a temperature of 500 °C to 1400 °C to form a silicon-containing copper catalyst comprising at least 0.1 % (w/w) of silicon. Step (ii) includes contacting the silicon-containing copper catalyst with an organohalide at a temperature of 100°C to 600 °C to form a reaction product. The organohalide has formula HaCbXc, where X is a halogen atom, subscript a is an integer of 0 or more, subscript b is an integer of 1 or more, and subscript c is an integer of 2 or more. The method produces a reaction product. The reaction product includes a halogenated silahydrocarbylene.
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Paragraph 0038
(2014/05/07)
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- Phosphine-Catalyzed Si-C Coupling of Bissilylmethanes: Preparation of Cyclic (Cl2SiCH2)2 and Linear Cl 2Si(CH2SiCl3)2 via Silylene and Silene Intermediates
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Cyclic and linear carbosilanes, (Cl2SiCH2) 2 (2) and Cl2Si(CH2SiCl3) 2 (3), were produced from phosphine-catalized Si-C coupling reactions of bissilylmethanes, HCl2SiCH2SiX1X 2Cl (X1, X2 = Cl (1), X1 = H, X 2 = Cl (7), and X1 = Me, X2 = Cl (8)). The formation of compounds 2 and 3 suggested competing reaction pathways, involving dichlorosilene [CH2=SiCl2] and dichlorosilylene [:SiCl2] intermediates. Each intermediate was either proposed by the product isolation of the trimerized product (3) or confirmed by trapping experiments with 2,3-dimethylbutadiene and methylene chloride.
- Hong, Soon Hyun,Hyun, Sang Il,Jung, Il Nam,Han, Won-Sik,Kim, Min-Hye,Yun, Hoseop,Nam, Suk-Woo,Kang, Sang Ook
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experimental part
p. 687 - 691
(2010/05/15)
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- Si-C coupling reaction of polychloromethanes with HSiCl3 in the presence of Bu4PCl: Convenient synthetic method for bis(chlorosilyl)methanes
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Coupling reaction of polychloromethanes CH4-nCln (n = 2-4) with HSiCl3 in the presence of tetrabutylphosphonium chloride (Bu4PCl) as a catalyst occurred at temperatures ranging from 30 °C to 150 °C. The reactivity of polychloromethanes increases as the number of chlorine-substituents on the carbon increases. In the reactions of CCl4 with HSiCl3, a variety of coupling products such as bis(chlorosilyl)methanes CH2(SiCl3)(SiXCl2) [X = Cl (1a), H (1b)], (chlorosilyl)trichloromthanes Cl3CSiXCl2 [X = Cl (2a), H (2b)], and (chlorosilyl)dichloromthanes Cl2HCSiXCl2 [X = Cl (3a), H (3b)] were obtained along with reductive dechlorination products such as CHCl3 and CH2Cl2 depending on the reaction temperature. In the reaction of CCl4, 2a is formed at the initial stage of the coupling reaction and converted to give CHCl3 at low temperature of 30 °C, to give 1a, 3a, and CHCl3 at 60 °C, and to afford 1a as major product and CH2Cl2 in competition above 100 °C. Si-H bond containing silylmethanes can be formed by the H-Cl exchange reaction with HSiCl3. Reaction of CHCl3 with HSiCl3 took placed at 80 °C to give three compounds 1a, 3a, and CH2Cl2, and finally 3a was converted to give 1a and CH2Cl2 at longer reaction time. While the condition for the reaction of CH2Cl2 with HSiCl3 required a much higher temperature of 150 °C. Under the optimized conditions for synthesizing bis(chlorosilyl)methanes 1a,b, a mixture of 1a and 1b were obtained as major products in 65% (1a:1b = 64:1) and 47% (42:5) yields from the reaction of CCl4 and CHCl3 at 100 °C for 8 h, respectively, and in 41% (34:7) yield from that of CH2Cl2 at 170 °C for 12 h. In the Si-C coupling reaction of polychloromethanes with HSiCl3, it seems likely that a trichlorosilyl anion generated from the reaction of HSiCl3 with Bu4PCl is an important key intermediate.
- Jung, Dong Euy,Kang, Seung-Hyun,Han, Joon Soo,Lim, Weon Cheol,Park, Young-ae W.,Yoo, Bok Ryul
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p. 3901 - 3906
(2008/03/12)
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- Effects of hydrogen chloride addition to the direct reaction of methylene chloride with elemental silicon
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Direct synthesis of bis(chlorosilyl)methanes has been reinvestigated by reacting elemental silicon simultaneously with methylene chloride and hydrogen chloride in the presence of copper catalyst using a stirred reactor equipped with a spiral band agitator at a carefully controlled temperature between 260 and 340°C. Bis(dichlorosilyl)methane and (dichlorosilyl)(trichlorosilyl)methane were obtained as the major products and bis(trichlorosilyl)methane as a minor product along with trichlorosilane and tetrachlorosilane derived from the reaction between elemental silicon and hydrogen chloride. The decomposition of methylene chloride was suppressed and the production of polymeric carbosilanes reduced by adding hydrogen chloride to the methylene chloride reactant. The optimum mixing ratio of methylene chloride and hydrogen chloride for the direct synthesis of bis(silyl)methanes was 1 : 4. The deactivation problem of elemental silicon owing to decompositions of methylene chloride and polycarbosilanes was eliminated. Cadmium was a good promoter for the reaction, while zinc was found to be an inhibitor for this particular reaction.
- Yeon, Seung Ho,Han, Joon Soo,Yoo, Bok Ryul,Jung, Il Nam
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