- Synthesis of Dibenzosiloles through Electrocatalytic Sila-Friedel-Crafts Reaction
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A novel electrocatalyzed method for the preparation of dibenzosiloles was developed through intramolecular C?H/Si?H dehydrogenative coupling strategy starting from biarylhydrosilanes. Both electro-donating and electro-withdrawing substitution groups were tolerated for this transformation, and the desired dibenzosilole products could be obtained in moderate to excellent yields. A sila-Friedel-Crafts reaction mechanism was proposed on the basis of previous literature and our controlled experiments. (Figure presented.).
- Han, Pan,Yin, Mengyun,Li, Haiqiong,Yi, Jundan,Jing, Linhai,Wei, Bangguo
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p. 2757 - 2761
(2021/04/16)
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- Novel compound and organic light emitting device comprising the same
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The present invention provides a novel compound and an organic light emitting device comprising the same. A compound represented by chemical formula 1 can be used as a material of an organic material layer of the organic light emitting device, and can improve efficiency, low driving voltage, and/or lifespan characteristics in the organic light emitting device.COPYRIGHT KIPO 2020
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Paragraph 0191-0194
(2020/03/05)
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- Silyldefluorination of Fluoroarenes by Concerted Nucleophilic Aromatic Substitution
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The reaction of readily generated silyl lithium reagents with various aryl fluorides to provide the corresponding aryl silanes is reported. DFT calculations reveal that the nucleophilic aromatic substitution of the fluoride anion by the silyl lithium reagent proceeds through concerted ipso substitution. In contrast to the classical nucleophilic aromatic substitution, this concerted ionic silyldefluorination also occurs on more electron-rich aryl fluorides.
- Mallick, Shubhadip,Xu, Pan,Würthwein, Ernst-Ulrich,Studer, Armido
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supporting information
p. 283 - 287
(2018/12/13)
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- Visible-Light Induced Radical Silylation for the Synthesis of Dibenzosiloles via Dehydrogenative Cyclization
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A visible-light induced radical silylation to dibenzosiloles from biarylhydrosilanes is described. The products were obtained in satisfactory yields under mild and water/air compatible conditions, providing an efficient and practical method for the synthesis of difunctionalized siloles by using a cheap organic dye photocatalyst. The method is tolerated by a wide range of functional groups and has a broad substrate scope. Light/dark experiments and quantum yield measurements provided support for a photocatalytic pathway rather than a chain process. (Figure presented.).
- Yang, Chao,Wang, Jing,Li, Jianhua,Ma, Wenchao,An, Kun,He, Wei,Jiang, Chao
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p. 3049 - 3054
(2018/08/06)
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- 9-Silafluorenes via base-promoted homolytic aromatic substitution (BHAS) - The electron as a catalyst
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Transition-metal-free intramolecular radical silylation of 2-diphenylsilylbiaryls via base-promoted homolytic aromatic substitution (BHAS) to give 9-silafluorenes is reported. 2-Diphenylsilylbiaryls are readily prepared, and cross dehydrogenative silylation occurs with tert-butylhydroperoxide (TBHP) as a cheap stoichiometric oxidant in the presence of a small amount of tetrabutylammonium iodide (TBAI) as an initiator. These cyclizations are catalyzed by the electron.
- Leifert, Dirk,Studer, Armido
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p. 386 - 389
(2015/01/30)
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- A Catalytic SEAr Approach to Dibenzosiloles Functionalized at Both Benzene Cores
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A general procedure for the catalytic preparation of dibenzosiloles functionalized at one or both benzene rings starting from readily available ortho-silylated biphenyls is reported. This method provides rapid access to silole building blocks substituted with chlorine atoms at both phenylene groups, thereby allowing catalytic access to directly polymerizable dibenzosiloles. Moreover, it is shown that, despite the involvement of highly electrophilic intermediates, a considerable range of Lewis-basic, for example, oxygen- and nitrogen-containing, functional groups is tolerated. The mechanism of this intramolecular electrophilic aromatic substitution (SEAr) proceeds through a sulfur-stabilized silicon cation, generated catalytically from the hydrosilane precursor.
- Omann, Lukas,Oestreich, Martin
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supporting information
p. 10276 - 10279
(2015/09/01)
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- B(C6F5)3-catalyzed synthesis of benzofused-siloles
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The dehydrosilylation of 2-(SiR2H)-biphenyls catalyzed by B(C6F5)3 and a weak base forms silafluorenes with H2 as the only byproduct. Attempts to extend this approach to synthesize siloles derived from 2,2′-bithiophenes and N-Me-2-Ph-indole resulted in competing reactivity, including protodesilylation. B(C6F5)3 also catalyzed the one-pot, two-step formation of silaindenes from aryl-alkynes by alkyne trans-hydrosilylation, followed by an intramolecular Sila-Friedel-Crafts reaction facilitated by a weak base.
- Curless, Liam D.,Ingleson, Michael J.
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supporting information
p. 7241 - 7246
(2015/03/03)
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- Versatile synthesis of blue luminescent siloles and germoles and hydrogen-bond-assisted color alteration
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(Figure Presented) Deeper in the blue: A versatile procedure has been developed for the preparation of photoluminescent siloles and germoles by palladium-catalyzed cross-coupling of 2,2′-diiodobiaryls with dihydrosilanes and -germanes. The dibenzosiloles and -germoles with ester moieties on the aromatic ring exhibited different emission wavelengths in the solution and crystalline states, attributable to the intermolecular interactions (see figure).
- Yabusaki, Yusuke,Ohshima, Norikazu,Kondo, Hitoshi,Kusamoto, Tetsuro,Yamanoi, Yoshinori,Nishihara, Hiroshi
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experimental part
p. 5581 - 5585
(2010/07/16)
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- Modular approach to silicon-bridged biaryls: Palladium-catalyzed intramolecular coupling of 2-(arylsilyl)aryl triflates
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(Chemical Equation Presented) Bridge of Si: Intramolecular direct arylation of 2-(arylsilyl)aryl triflates is catalyzed smoothly by Pd(OAc) 2/PCy3 in the presence of Et2NH in dimethylacetamide (DMA), giving rise to the corresponding silicon-bridged biaryls in good to excellent yields. The new approach has led to the synthesis of a silicon-bridged 2-phenylindole (see scheme) that exhibits blue photoluminescence in the solid state with extremely high quantum yields.
- Shimizu, Masaki,Mochida, Kenji,Hiyama, Tamejiro
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supporting information; experimental part
p. 9760 - 9764
(2009/05/30)
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- Silacyclopentadiene derivatives and an organic electroluminescent element obtained by using the silacyclopentadiene derivative
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An electroluminescence element (EL) obtained by using a silacyclopentadiene. derivation expressed by the general formula (I) and the derivative are provided. STR1 (wherein X and Y are independently hydrocarbon radicals with from 1 to 6 atoms and R1 to R4 are hydrogen, halogens, alkyl radicals with from 1 to 6 carbon atoms, or a condensed (un)substituted ring if being adjacent).
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- CHEMISTRY OF SILOLES. THE REACTIONS OF SILOLES WITH ORGANOLITHIUM REAGENTS
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The chemical behaviour of siloles toward various organolithium reagents in THF has been investigated.The reaction of 1-methyl-1-(trimethylsilyl)-, 1-phenyl-1-(trimethylsilyl)- and 1,1-bis(trimethylsilyl)dibenzosilole(I, II and III) with a large excess of an alkyllithium such as methyllithium or butyllithium afforded 1,1-dialkyldibenzosiloles in quantitative yields.Treatment of I with an excess of phenyllithium gave a mixture of 1-methyl-1-phenyl- and 1,1-diphenyldibenzosilole quantitatively, while with an excess of tert-butyllithium, I afforded 1,1-dimethyl and 1-tert-butyl-1-methyldibenzosilole in low yield.Similar treatment of I and II with 1 equiv. of methyl- or butyl-lithium yielded a mixture of the corresponding mono- and dialkyl-substituted dibenzosiloles. 1-Methyl-3,4-diphenyl-1,2,5-tris(trimethylsilyl)silole reacted with methyllithium in THF to give 1,1-dimethyl-3,4-diphenyl-2,2,5-tris(trimethylsilyl)silole.Similarly, both 2,4-diphenyl-1,1,3,5-tetrakis(trimethylsilyl)silole and 4,5-diphenyl-1,1,2,3-tetrakis(trimethylsilyl)silole with methyllithium afforded two isomers of 1-methyl-2,4-diphenyl-1,2,3,5-tetrakis(trimethylsilyl)-1-silacyclopent-3-ene in a ratio of 3:2 in high yields.
- Ishikawa, Mitsuo,Tabohashi, Tatsuru,Sugisawa, Hiroshi,Nishimura, Kunio,Kumada, Makoto
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p. 109 - 120
(2007/10/02)
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