- Access to Stabilized Silyl Anions by Electroreduction of Chlorosilanes
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Using the sacrificial anode technique, the electroreduction of arylchlorosilanes into the corresponding arylhydrosilanes occurs via a silylaluminium intermediate characterized for the first time in such reactions.
- Duprat, C.,Biran, C.,Bordeau, M.,Constantieux, T.,Gerval, P.,Dunogues, J.
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- Raman and infrared vibrational spectra, ab initio calculations and normal coordinate analyses for 1,2-dimethyltetrachlorodisilane and 1,2-dimethyltetrachlorodisilane-d6
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The Raman spectra of CH3Cl2SiSiCl2CH3 and CD3Cl2SiSiCl2CD3 between 3000 and 30 cm-1 have been recorded at various temperatures. The infrared spectra at ambient temperature were recorded from 3000 to 50 cm-1. Both isotopomers exist as a mixture of gauche and anti rotamers at room temperature. The energy difference E(anti)-E(gauche) was determined from the Raman spectra as being -0.9 ± 0.2 kJ mol-1 for CH3Cl2SiSiCl2CH3 and -1.2 ± 0.2 kJ mol-1 for CD3Cl2SiSi2CD3. Assisted by ab initio calculations, the vibrational spectra have been assigned using C(2h) symmetry for the anti rotamers and C2 symmetry for the gauche rotamers. Scaled and unscaled harmonic frequencies and harmonic symmetry force constants have been reported for both rotamers, and normal coordinate analyses have been carried out. Potential energy distributions have been reported.
- Ernst, Margot,Schenzel, Karla,Jaehn, Anke,Hassler, Karl
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- A Quantitative NMR Method for Silyllithium Analysis
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A rapid and extremely simple method for silyl anion analysis is presented. The progress of silyllithium reagent preparation can be determined by quenching an aliquot with neat chloro(trimethyl)silane, evaporation, dilution with CDCl 3, and direct proton NMR analysis. This procedure is fast, simple, and allows for identification and relative quantification of the starting reagent, intermediates, and the silyllithium product.
- Bo, Yingjian,Sieburth, Scott McN.
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- METHOD FOR PRODUCING SILYL SODIUM COMPOUND AND METHOD FOR DEOXIDIZING EPOXY COMPOUND
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PROBLEM TO BE SOLVED: To construct a technique which can simply, efficiently and inexpensively synthesize a silyl sodium compound in a small number of processes and in a short time, especially to construct a technique which synthesizes a silyl sodium compound by using easily available reagents from a viewpoint of sustainability without using reagents which are difficult to handle and are toxic. SOLUTION: There is provided a method for synthesizing a silyl sodium compound comprising a step of reacting a dispersion obtained by dispersing a silyl halide compound or a disilane compound with sodium into a dispersion solvent, the silyl halide compound or the disilane compound as a starting compound, in a reaction solvent to obtain the silyl sodium compound. There is also provided a method for deoxidizing an epoxy compound comprising a step of reacting the silyl sodium compound obtained by synthesizing method of the silyl sodium compound with an epoxy compound to deoxidize the epoxy compound to stereoselectively produce an alkene compound. SELECTED DRAWING: Figure 1 COPYRIGHT: (C)2020,JPOandINPIT
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Paragraph 0084-0086
(2020/05/06)
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- Disilane and preparation method thereof
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The invention discloses disilane and a preparation method thereof. The preparation method of disilane includes: subjecting a uniformly mixed reaction system containing tertiary hydrosilane and a catalyst to dehydrogenation reaction at a temperature ranging from -10DEG C to 120DEG C to obtain disilane, wherein the catalyst comprises a silver salt. The invention also discloses the disilane preparedby the method. The method for preparation of the disilane by catalyzing tertiary silane dehydrogenation with the silver salt adopts the silver salt to activate the Si-H bond in the silane so as to realize construction of disilane. Therefore, the invention provides an efficient and simple method for preparation of the compound, and the application prospect is wide.
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Paragraph 0039-0042
(2020/01/25)
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- Method for continuously preparing disilane compounds by micro-reaction device
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The invention discloses a method for continuously preparing disilane compounds by a micro-reaction device. The method comprises the following steps: (1) a solution A is prepared from organosilane by dissolving in a first organic solvent, or is organosilane; (2) a solution B is prepared from an oxidant by dissolving in a second organic solvent, or is an oxidant; (3) the solution A and the solutionB are pumped into a micro-mixer of the micro-reaction device simultaneously for mixing, a product then flows into a microreactor of the micro-reaction device for reaction, and the disilane compounds are prepared, wherein the microreactor is filled with a catalyst. Raw materials required in the method are easily available and have better stability, metal copper compounds are used as a catalyst forcoupling reaction on trisubstituted silanes, and the coupling effect on trisubstituted silanes is better than that of alkali metal catalysts and transition metal catalysts; a micro-channel reactor issuitable for an exothermic coupling reaction due to good mixing and heat transfer performance.
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Paragraph 0025; 0026; 0027-0030; 0041-0062; 0065-0088
(2018/05/16)
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- Pinacol couplings of a series of aldehydes and ketones with SmI2/Sm/Me3SiCl in DME
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The pinacol coupling is one of the most significant methods to synthesize vic-diols. The combination of samarium diiodide (SmI2) and samarium metal successfully induces the selective pinacol couplings of not only aromatic aldehydes and ketones but also aliphatic ones in the presence of trimethylchlorosilane (Me3SiCl) in 1,2-dimethoxyethane (DME). DME is the most suitable solvent for the reduction system using SmI2 and Me3SiCl. Me3SiCl, a widely available additive, prevents the decomposition of the formed vic-diols, i.e., meso-isomers, and controls their stereochemistry. In particular, the pinacol couplings of sterically hindered aliphatic aldehydes and ketones proceed with excellent diastereoselectivities to afford dl-isomers in good yields.
- Yoshimura, Aya,Saeki, Tomokazu,Nomoto, Akihiro,Ogawa, Akiya
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p. 5347 - 5355
(2015/07/15)
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- Efficient fluoride-catalyzed conversion of CO2 to CO at room temperature
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A protocol for the efficient and selective reduction of carbon dioxide to carbon monoxide has been developed. Remarkably, this oxygen abstraction step can be performed with only the presence of catalytic cesium fluoride and a stoichiometric amount of a disilane in DMSO at room temperature. Rapid reduction of CO2 to CO could be achieved in only 2 h, which was observed by pressure measurements. To quantify the amount of CO produced, the reduction was coupled to an aminocarbonylation reaction using the two-chamber system, COware. The reduction was not limited to a specific disilane, since (Ph 2MeSi)2 as well as (PhMe2Si)2 and (Me3Si)3SiH exhibited similar reactivity. Moreover, at a slightly elevated temperature, other fluoride salts were able to efficiently catalyze the CO2 to CO reduction. Employing a nonhygroscopic fluoride source, KHF2, omitted the need for an inert atmosphere. Substituting the disilane with silylborane, (pinacolato)BSiMe2Ph, maintained the high activity of the system, whereas the structurally related bis(pinacolato)diboron could not be activated with this fluoride methodology. Furthermore, this chemistry could be adapted to 13C-isotope labeling of six pharmaceutically relevant compounds starting from Ba13CO 3 in a newly developed three-chamber system.
- Lescot, Camille,Nielsen, Dennis U.,Makarov, Ilya S.,Lindhardt, Anders T.,Daasbjerg, Kim,Skrydstrup, Troels
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supporting information
p. 6142 - 6147
(2014/05/20)
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- Reactions of molybdenum hydrides with organochlorosilanes: Silicon-silicon bond formation under mild conditions
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Reactions of molybdenum hydrides containing polydentate phosphinoalkylsilyl ligands with a number of chlorosilanes have been investigated; this has led to the discovery of a novel type of a dechlorinative Si-Si coupling reaction.
- Asaeda, Takahiro,Lee, Joo Yeon,Watanabe, Kyosuke,Minato, Makoto
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p. 1005 - 1007
(2014/07/22)
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- Photoinduced reductive coupling of organochlorosilanes with SmI2/Sm
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We report efficient reductive dimerization of chlorosilanes with SmI2/Sm in 1,2-dimethoxyethane upon visible light irradiation. This procedure can be applied to the synthesis of polysilanes from dichlorosilanes. The molecular weight of the obtained polysilanes was higher and their molecular weight distribution was narrower than the polysilanes produced by reactions with SmI2/Sm in dark.
- Yoshimura, Aya,Tomisaka, Yuri,Li, Zhifang,Nomoto, Akihiro,Ogawa, Akiya
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p. 684 - 689
(2015/02/02)
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- Mechanistic insights into the reaction of enantiomerically pure lithiosilanes and electrophiles: Understanding the differences between aryl and alkyl halides
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The reactivity of enantiomerically pure lithiosilanes against aliphatic and aromatic halo electrophiles has been investigated with the focus on product composition and enantiomeric ratios as a basis for a better understanding of ongoing mechanisms. Both parameters are strongly influenced by both the organic group and the corresponding halide of the used electrophile. Thus, high stereoselectivities and yields are only obtained if one distinct reaction mechanism dominates. In the case of aliphatic electrophiles, experimental and quantum chemical studies support the preference of an SN2 mechanism for chlorides resulting in retention of configuration on silicon, whereas bromides tend to react under inversion through a halide-lithium exchange (ate complex). For aromatic electrophiles these relationships change: chlorides and bromides both favor the formation of an ate complex over nucleophilic aromatic substitution, leading to inversion of configuration on silicon.
- Daeschlein, Christian,Bauer, Simeon O.,Strohmann, Carsten
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experimental part
p. 1454 - 1465
(2011/06/20)
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- PREPARATION OF SI-SI BOND-BEARING COMPOUNDS
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Si—Si bond-bearing compounds are effectively prepared by irradiating with radiation or heating Si—H group-bearing silicon compounds in organic solvents in the presence of iron complex catalysts. The Si—Si bond-bearing compounds are useful as a base material in photoresist compositions, ceramic precursor compositions, and conductive compositions.
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Page/Page column 3
(2009/05/28)
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- Direct construction of silicon-silicon bond by using the low-valent titanium reagent
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The reductive dimerization or polymerization of organochlorosilanes has been achieved by using the low-valent titanium reducing agent other than the alkali metals that are invariable used in the Wurtz-type coupling reaction. Applying this method, the corresponding disilanes or poly(methylvinylsilane) was obtained in good yields. The poly(methylvinylsilane) synthesized by this method is highly pure with a high molecular weight and a narrow molecular weight distribution (Mw/Mn = 1.6, Mn = 16,860).
- Lai, Guoqiao,Li, Zhifang,Huang, Jiabang,Jiang, Jianxiong,Qiu, Huayu,Shen, Yongjia
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p. 3559 - 3562
(2008/02/12)
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- Electroreductive Synthesis of Polysilanes, Polygermanes, and Related Polymers with Magnesium Electrodes
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The electroreduction of alkylaryldichlorosilane carried out with Mg cathode and anode in a single compartment cell gave high molecular weight poly(alkylarylsilane) (Mn = 5200-31000, Mw/Mn = 1.4-1.8) in 5-79% yield. The effects of electrode material, monomer concentration, amount of supplied electricity, and ultrasound were investigated. This electroreductive method was also successfully applied to the synthesis of polygermanes, silane-geramane copolymers, and also poly[p-(disilanylene)phenylenes].
- Kashimura, Shigenori,Ishifune, Manabu,Yamashita, Natsuki,Bu, Hang-Bom,Takebayashi, Masakatsu,Kitajima, Satsuki,Yoshiwara, Daisuke,Kataoka, Yasuki,Nishida, Ryoichi,Kawasaki, Shin-Ichi,Murase, Hiroaki,Shono, Tatsuya
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p. 6615 - 6621
(2007/10/03)
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- Electrolytic Behavior of Iodo- and Chlorosilanes. The Formation of Si-Si and Si-sp-C Bonds
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Electrolysis of iodosilanes with Al/Pt electrodes in pivalonitrile results in the formation of the Si-Si bonds to give the corresponding disilanes.On the other hand, the electrolysis of various halosilanes such iodo-, chloro-, and fluorosilanes with Pt/Pt electrodes in the presence of phenylacetylene leads to the formation of the Si-sp-carbon bonds to give phenylethynylated products.
- Kunai, Atsutaka,Ohnishi, Osamu,Sakurai, Tomohiro,Ishikawa, Mitsuo
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p. 1051 - 1052
(2007/10/03)
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- Reactions of methylchlorodisilanes with Grignard reagents
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Reactions of Cl2MeSiSiMeCl2 with RMgCl make it possible to obtain and isolate pure disilanes containing a smaller number of functional groups, namely, RMeClSiSiMeCl2 (R = Ph), RMeClSiSiMeRCl (R = Pri, Ph), and R2MeSiSiMeRCl (R = Bui).The reaction of Cl2MeSiSiMeCl2 with BunMgCl is the least selective.The chlorides obtained were reduced with LiAlH4 into the corresponding hydrides.
- Semenov, V. V.,Ladilina, E. Yu.,Chesnokova, T. A.,Elistratova, N. K.,Kurskii, Yu. A.,Makarenko, N. P.
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p. 927 - 930
(2007/10/02)
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- Method for producing disilanes
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A method for producing disilane characterized in that halosilane is subjected to electrochemical reaction using Al, Al alloy, Mg, Mg alloy, Cu, Cu alloy, Zn or Zn alloy as anode, a lithium salt as supporting electrolyte, an Al salt, Fe salt, Mg salt, Zn salt, Sn salt, Co salt, Pd salt, V salt, Cu salt, Ca salt, Na salt or K salt as current carrying aid, and an aprotic solvent as solvent, thereby producing disilane.
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- Electrochemical Reduction of Dichlorosilanes in the Presence of 2,3-Dimethylbutadiene
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Electrolytic reduction of dichloromethylphenyl-, dichlorodiphenyl-, dichloro-o-tolyl-, and dichlorodi-p-tolylsilanes in the presence of 2,3-dimethylbutadiene afforded 1-methyl-1-phenyl-, 1,1-diphenyl-, 1,1-di-o-tolyl-, and 1,1-di-p-tolyl-3,4-dimethyl-1-silacyclopent-3-ene, respectively, while the similar reaction of chloromethyldiphenylsilane with 2,3-dimethylbutadiene afforded 1-(methyldiphenylsilyl)- and 1,4-bis(methyldiphenylsilyl)-2,3-dimethyl-2-butene.A reaction mechanism leading to these products has been discussed.
- Kunai, Atsutaka,Ueda, Takafumi,Toyoda, Eiji,Ishikawa, Mitsuo
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p. 287 - 289
(2007/10/02)
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- Electrochemical Oxidation of Hydrosilanes. A Synthetic Approach to Halosilanes and Disilanes
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Electrolytic oxidation of dimethylphenylsilane (1) in the presence of CuCl2 or CuCl afforded chlorodimethylphenylsilane in high yields (>90percent), while similar electrolysis of 1 in the presence of BF4- ions afforded fluorodimethylphenylsilane in 90percent yield. 1,2-Diphenyltetramethyldisilane was obtained from 1 in 48percent yield by the electrolysis with a Pt-Cu electrode system.A "paired" electrolysis of methyldiphenylsilane on the anode and chloromethyldiphenylsilane on the cathode afforded 1,2-dimethyltetraphenyldisilane in 64percent yield.
- Kunai, Atsutaka,Kawakami, Toshihiro,Toyoda, Eiji,Sakurai, Tomohiro,Ishikawa, Mitsuo
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p. 1945 - 1948
(2007/10/02)
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- Electroreductive Formation of Polysilanes
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Electroreduction of dichlorosilanes, such as 1,1-dichlorodialkylsilanes, 1,2-dichlorotetra-alkyldisilanes, and 1,4-bis(chlorodialkylsilyl)benzenes, with Mg electrodes in a single-compartment cell was found to yield the corresponding polysilanes.
- Shono, Tatsuya,Kashimura, Shigenori,Ishifune, Manabu,Nishida, Ryoichi
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p. 1160 - 1161
(2007/10/02)
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- Efficient formation and cleavage of disilanes by potassium-graphite. Silylation with silyl metal reagents
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Potassium-graphite laminate (C8K) very rapidly forms disilanes from chlorosilanes and then rapidly cleaves the disilanes to give silyl potassium reagents which can be converted into potassium silyl cuprates, -manganates, and -vanadates that are useful for various nucleophilic substitution and addition reactions.
- Fuerstner, Alois,Weidmann, Hans
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- Chlorine-Bromine-Exchange in Disilanes
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Redistribution reactions between a mixture of Si2Me2Cl4 and Si2Me2Br4 show an exchange of halogen atoms at room temperature.After 10 hours at 60 deg C the equilibrium state is attained and all possible compounds Si2Me2Cl4-nBrn are formed, but not in a statistical distribution.Possible reasons for this distribution and general rules for the exchange of substituents on disilanes are postulated. - Keywords: Disilane; Redistribution reaction; Cl/Br-Exchange
- Schmoelzer, Harald,Hengge, Edwin
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p. 1125 - 1132
(2007/10/02)
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