- Conformational studies by dynamic NMR. 71. Stereodynamics of triisopropyl(aryl)silanes in solution and in the solid state
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A study has been carried out of the conformations of triisopropyl(aryl)silanes (i-Pr)3SiAr, (Ar = phenyl, 1-naphthyl, and 2- naphthyl) both as to the orientation of the three isopropyl groups and the conformation about the silicon-aromatic bond
- Anderson, J. Edgar,Casarini, Daniele,Lunazzi, Lodovico,Mazzanti, Andrea
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- Continuous-flow Si-H functionalizations of hydrosilanesviasequential organolithium reactions catalyzed by potassiumtert-butoxide
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We herein report an atom-economic flow approach to the selective and sequential mono-, di-, and tri-functionalizations of unactivated hydrosilanesviaserial organolithium reactions catalyzed by earth-abundant metal compounds. Based on the screening of various additives, we found that catalytic potassiumtert-butoxide (t-BuOK) facilitates the rapid reaction of organolithiums with hydrosilanes. Using a flow microreactor system, various organolithiums bearing functional groups were efficiently generatedin situunder mild conditions and consecutively reacted with hydrosilanes in the presence oft-BuOK within 1 min. We also successfully conducted the di-funtionalizations of dihydrosilane by sequential organolithium reactions, extending to a gram-scale-synthesis. Finally, the combinatorial functionalizations of trihydrosilane were achieved to give every conceivable combination of tetrasubstituted organosilane libraries based on a precise reaction control using an integrated one-flow system.
- Lee, Hyune-Jea,Kwak, Changmo,Kim, Dong-Pyo,Kim, Heejin
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supporting information
p. 1193 - 1199
(2021/02/26)
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- Silylation of Aryl Chlorides by Bimetallic Catalysis of Palladium and Gold on Alloy Nanoparticles
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Supported palladium-gold alloy-catalyzed cross-coupling of aryl chlorides and hydrosilanes enabled the selective formation of aryl-silicon bonds. Whereas a monometallic palladium catalyst predominantly promoted the hydrodechlorination of aryl chlorides and gold nanoparticles showed no catalytic activity, gold-rich palladium-gold alloy nanoparticles efficiently catalyzed the title reaction to give arylsilanes with high selectivity. A wide array of aryl chlorides and hydrosilanes participated in the heterogeneously-catalyzed reaction to furnish the corresponding arylsilanes in 34–80% yields. A detailed mechanistic investigation revealed that palladium and gold atoms on the surface of alloy nanoparticles independently functioned as active sites for the formation of aryl nucleophiles and silyl electrophiles, respectively, which indicates that palladium and gold atoms on alloy nanoparticles work together to enable the selective formation of aryl-silicon bonds. (Figure presented.).
- Miura, Hiroki,Masaki, Yosuke,Fukuta, Yohei,Shishido, Tetsuya
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p. 2642 - 2650
(2020/04/22)
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- Preparation, X-ray Structure, and Reactivity of Triisopropylsilyl-Substituted Aryliodonium Salts
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(4-Triisopropylsilylphenyl)phenyliodonium tosylate, an aryliodonium salt bearing an extremely bulky, electron-donating triisopropylsilyl (TIPS) substituent in the phenyl ring, was prepared by the reaction of (4-tributyltinphenyl)triisopropylsilane with [h
- Yusubov, Mekhman S.,Svitich, Dmitrii Yu.,Yoshimura, Akira,Kastern, Brent J.,Nemykin, Victor N.,Zhdankin, Viktor V.
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supporting information
p. 4831 - 4834
(2015/08/03)
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- SELECTIVE MONO- OR DIMETALATION OF ARENES BY MEANS OF SUPERBASIC REAGENTS
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If employed in tetrahydrofuran, stoichiometric amounts of butyllithium and potassium tert-butoxide react with benzene under clean monometalation.In hexane suspension, however, considerable amounts of meta- and para-disubstituted by-products are obtained (approx. 10percent).They become preponderant if a three-fold excess of the metalating agent is used.Naphthalene leads under the same conditions to a mixture of two mono- and ten di-substituted derivatives. - Alkyl groups, as present in tert-butylbenzene, retard the metalation at both m- and p-positions, while trialkylsilyl groups deactivate only m-position.In either case exclusive monosubstitution occurs. - Perdeuterobenzene undergoes metalation and subsequent electrophilic mono- or disubstitution to afford isotope labeled compounds with moderate, though synthetically attractive yields.The kinetic isotope effects and product ratios can be taken as evidence for aggregate formation at the level of both the superbasic metalating reagent and the organometallic intermediates.
- Schlosser, Manfred,Choi, Jung Hoon,Takagishi, Sadahito
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p. 5633 - 5648
(2007/10/02)
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