- Silylation of Alcohols, Phenols, and Silanols with Alkynylsilanes – an Efficient Route to Silyl Ethers and Unsymmetrical Siloxanes
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The formation of several silyl ethers (alkoxysilanes, R3Si-OR') and unsymmetrical siloxanes (R3Si-O-SiR'3) can be catalyzed by the commercially available potassium bis(trimethylsilyl)amide (KHMDS). The reaction proceeds via direct dealkynative coupling between various alcohols or silanols and alkynylsilanes, with a simultaneous formation of gaseous acetylene as the sole by-product. The dehydrogenative and dealkenative coupling of alcohols or silanols are well-investigated, whilst the utilization of alkynylsilanes as silylating agents has never been comprehensively studied in this context. Overall, the presented system allows the synthesis of various attractive organosilicon compounds under mild conditions, making this approach an atom-efficient, environmentally benign, and sustainable alternative to existing synthetic solutions.
- Kuciński, Krzysztof,Stachowiak, Hanna,Hreczycho, Grzegorz
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p. 4042 - 4049
(2020/07/04)
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- O-Metalation of silanols and POSS silanols over Amberlyst-15 catalyst: A facile route to unsymmetrical siloxanes, borasiloxanes and germasiloxanes
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A simple and highly practical Amberlyst-catalyzed direct O-metalation of silanols, POSS silanols and alkoxysilanes under mild conditions is proposed. This protocol can be applied to the synthesis of a wide range of important organosilicon derivatives such as siloxanes, germasiloxanes, borasiloxanes and functionalized silsesquioxanes. It is worth noting that Amberlyst-15 can be reused for further experiments and its catalytic activity in this process is well-preserved for several recycling steps.
- Kuciński, Krzysztof,Hreczycho, Grzegorz
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p. 261 - 266
(2019/03/27)
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- A Highly Effective Route to Si?O?Si Moieties through O-Silylation of Silanols and Polyhedral Oligomeric Silsesquioxane Silanols with Disilazanes
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A simple and highly practical catalyst-free O-silylation of silanols with commercially available disilazanes has been developed under mild conditions. In the case of polyhedral oligomeric silsesquioxane (POSS) silanols and some other silanols, it was necessary to use catalytic amounts of inexpensive Bi(OTf)3 as additional catalyst. This efficient chlorine-free protocol involves the synthesis of a wide range of important organosilicon derivatives such as unsymmetrical disiloxanes and functionalized silsesquioxanes.
- Kuciński, Krzysztof,Hreczycho, Grzegorz
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p. 1043 - 1048
(2019/02/05)
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- Synthetic method of allyl acrylate
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The invention discloses a new synthetic method of allyl acrylate. According to the method, an organic silicon monomer with functional groups is used, and the allyl acrylate is prepared under the soft reaction condition. The synthetic method of the allyl acrylate includes three steps that (1) acryloxytrimethylsilane is synthesized; (2) allyloxy silane is synthesized; and (3) the acryloxytrimethylsilane and the allyloxy silane are mixed. According to the raw materials used in a reaction, chlorine elements are fully converted into inorganic salt, low-boiling-point chloride like phosphorus trichloride is not used, and it is guaranteed that the chlorine elements are not contained in a prepared product; reaction conditions are soft, and the requirement for the equipment is not high; purification is easy, boiling points of all components are large in difference, and reduced pressure distillation separation is easy; water washing is not needed, and amplification is easy; and trifluoromethanesulfonic acid serves as a catalyst, the high acidity is achieved, and double bonds cannot be damaged.
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Paragraph 0019
(2017/04/28)
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- Method for producing polyimidesiloxane
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PROBLEM TO BE SOLVED: To provide a method for synthesizing siloxanes at will in good yield while maintaining high structural controllability, which can be applied to substrates having various substituents.SOLUTION: The method comprises reacting benzyloxysilanes and silicon halides in the absence of hydrogen using a catalyst comprising a transition metal or a compound thereof, preferably a metal of group 9 or group 10 of the periodic table or a compound thereof. Thereby, corresponding siloxanes can be produced safely and simply in high yield under a mild reaction condition accompanied by elimination of a benzyl halide. Especially, by using an active carbon-supported catalyst as a heterogeneous catalyst, the target siloxanes can be separated easily.
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Paragraph 0038
(2018/10/16)
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- In a method of manufacturing a condition anhyride silanolated
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PROBLEM TO BE SOLVED: To provide a method capable of synthesizing silanol under an anhydrous condition and a mild condition, adapting to substrates having various substituents, and producing siloxanes freely at an excellent yield, while having high structure controllability.SOLUTION: By a hydrogen addition reaction in which benzyloxy-substituted silanes are used as a silanol precursor, and a metal in the group 9 or 10 on the periodic table or a metal compound is used as a catalyst, corresponding silanols can be produced safely and easily at a high yield under an anhydrous condition and a mild condition, and especially object silanols can be isolated easily by using a carbon-carrying catalyst.
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Paragraph 0033
(2018/03/24)
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- Pd/C-catalyzed cross-coupling reaction of benzyloxysilanes with halosilanes for selective synthesis of unsymmetrical siloxanes
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A new protocol for the nonhydrolytic synthesis of unsymmetrical siloxanes has been developed. The cross-coupling reaction of benzyloxysilanes with halosilanes catalyzed by Pd/C afforded various unsymmetrical siloxanes with co-production of benzyl halides. the Partner Organisations 2014.
- Igarashi, Masayasu,Kubo, Keiko,Matsumoto, Tomohiro,Sato, Kazuhiko,Ando, Wataru,Shimada, Shigeru
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p. 19099 - 19102
(2014/05/20)
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- Substituted lithiumtrimethylsiloxysilanides LiSiRR′(OSiMe3) - Investigations of their synthesis, stability and reactivity
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The reactions of the trimethylsiloxychlorosilanes (Me3SiO)RR′SiCl (1a-h: R′ = Ph, 1a: R = H, 1b: R = Me, 1c: R = Et, 1d: R = iPr, 1e: R = tBu, 1f: R = Ph, 1g: R = 2,4,6-Me3C6H2 (Mes), 1h: R
- Harloff, Joerg,Popowski, Eckhard,Reinke, Helmut
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p. 1421 - 1441
(2007/10/03)
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- Monosodiumoxyorganoalkoxysilanes: Synthesis and properties
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The reaction of organoalkoxysilanes with sodium hydroxide was studied in detail. Studies indicate that this reaction involves more than one stage and involves rather complex multistep process, which leads to the formation of both monosodiumoxyorganoalkoxysilanes (MSOAS) and several secondary products. Analysis of experimental evidence makes it possible to advance the mechanism behind this phenomenon and to define the optimum conditions for the preparation of pure MSOAS with high yields. Different MSOAS were synthesized and their basic physicochemical properties were studied. MSOAS are shown to constitute multifunctional reagents with chemically independent functional groups, and their reaction with trimethylchlorosilane selectively proceeds via - ONa groups, whereas their interaction with triethylesilanol and higher alcohols proceeds exclusively via - OAlk groups. Exchange interaction between MSOAS and organoalkoxysilanes via - ONa and - OAlk groups was found and studied in detail. Temperature corresponding to the onset of thermal degradation of MSOAS was estimated to be equal to ~ 180-190°C.
- Rebrov,Muzafarov
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p. 514 - 541
(2007/10/03)
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- Superoxide-stable ionic liquids: New and efficient media for electrosynthesis of functional siloxanes
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The electrogeneration of diorganylsilanones from difunctional precursors Y(CH2)3(Me)SiX2 and Ph2SiX 2 (Y = NH2, CF3, CN; X = Cl, OEt, OMe), performed in the presence of hexamethy
- Martiz, Bruno,Keyrouz, Robert,Gmouh, Said,Vaultier, Michel,Jouikov, Viatcheslav
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p. 674 - 675
(2007/10/03)
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- Electrochemical activation of diorganyl dialkoxysilanes for siloxane backbone extension
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The reaction of diorganyl dialkoxysilanes PhRSi(OAlk)2 (R = Ph, vinyl, OMe; Alk = Me, Et) with electrochemically reduced forms of oxygen provides reactive intermediates that insert into hexamethyldisiloxane or permethyl cyclosiloxanes, D3
- Keyrouz, Robert,Jouikov, Viatcheslav
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p. 902 - 904
(2007/10/03)
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- Novel fluoride ion mediated synthesis of unsymmetrical siloxanes under phase transfer catalysis conditions
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Unsymmetrical siloxanes have been prepared from silanols or hydrosilanes using phase transfer catalytic (PTC) systems Me3 SiN3-CsF-18-crown-6-toluene or Me3SiN 3-CsF-18-crown-6-H2O-toluene, correspond
- Abele, Ramona,Abele, Edgars,Fleisher, Mendel,Grinberga, Solveiga,Lukevics, Edmunds
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- Reaktionen von Trimethylsiloxychlorsilanen (Me3SiO)Me2-nPhnSiCl (n = 0, 1, 2) mit Lithium - Bildung von Trimethylsiloxy-substituierten Silyl- und Disilanyllithiumverbindungen sowie Di- und Trisilanen
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The trimethylsiloxychlorosilanes (Me3SiO)Me2-nPhnSiCl (1: n=0; 2: n=1; 3: n=2) were allowed to react with lithium metal in tetrahydrofuran (THF) and in a mixture of THF-diethylether-n-pentane in volume ratio 4:1:1 (Trapp mixture). The reaction of 1 with lithium metal in THF under refluxing leads to the homo-coupling product [(Me3SiO)Me2Si]2 (4). A mixture of 1 and Me3SiCl in molar ratio 1:2 reacts with lithium metal in THF to give 4 and the cross-coupling product (Me3SiO)Me2SiSiMe3 (7). The silyllithium derivatives Me3SiO(SiMePh)nLi (8: n = 1; 9: n = 2; 10: n = 3) and Me3SiSiMePhLi (11) are formed in the reaction of 2 with lithium metal in THF at -78°C and in the Trapp mixture at -110°C. Main product in both cases is 9. 8-11 are trapped by Me3SiCl and HMe2SiCl. The trapping products (Me3SiO)SiMePhSiMe3 (13a), Me3SiO(SiMePh)2SiMe2R (14a, 14b; a: R = Me, b: R = H), Me3SiO(SiMePh)3SiMe2R (15a, 15b) and Me3SiSiMePhSiMe2R (16a, 16b) are obtained. The reaction of 3 with lithium metal like 2 produces the silyllithium derivatives Me3SiO(SiPh2)nLi (18: n = 1, 19: n = 2) and Me3SiSiPh2Li (20), wich are trapped by Me3SiCl and HMe2SiCl to give the corresponding disilanes (Me3SiO)SiPh2SiMe2R (23a, 23b) and trisilanes Me3SiO(SiPh2)2SiMe2R (24a, 24b) as well as Me3SiSiPh2SiMe2R (25a, 25b). In addition to 18, 19 and 20 LiSiPh2SiPh2Li (21) is formed in a small amount in the reaction of 3 with lithium metal at -78°C to afford tetrasilanes [RMe2SiPh2Si]2 (26a, 26b) after trapping by Me3SiCl and HMe2SiCl. The disilane (Me3SiO)SiMeR′SiMe3 (17) (R′ = 3,4,5,6-tetrakis(trimethylsilyl)cyclohex-1-enyl) is produced by reaction of a mixture of 2 and Me3SiCl in molar ratio 1:6 with 6 equivalents of lithium at -78°C in THF. The reaction of a mixture of 3 and Me3SiCl in the molar ratio 1:10 with 11 equivalents of lithium under the same conditions gives (Me3SiO)SiR′2SiMe3 (27).
- Harloff, Joerg,Popowski, Eckhard,Fuhrmann, Hans
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p. 136 - 146
(2007/10/03)
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- Method for the cleavage of organic siloxanes, and products and applications thereof
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A method for the cleavage of organosiloxanes with chlorosilanes in the presence of ferric chloride and hydrogen chloride as catalysts resulting in chloroalkyl silanes or chloroaryl silanes, and organosiloxanes, which are characterized by one or more --O--Si--R3 groups, (R=alkyl or aryl), which are directly bound to a silicon atom which in turn is bound either to the same grouping or to an alkyl or aryl moiety.
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