13058-24-7Relevant articles and documents
A Stepwise Mechanism for Gas-Phase Unimolecular Ion Decompositions. Isotope Effects in the Fragmentation of tert-Butoxide Anion
Tumas, William,Foster, Robert F.,Pellerite, Mark J.,Brauman, John I.
, p. 961 - 970 (1987)
Infrared multiple photon (IRMP) photochemical activation of gas-phase ions trapped in an cyclotron resonance (ICR) spectrometer has been used to the mechanism of a gas-phase negative ion unimolecular decomposition.Upon irradiation with a CO2 laser (both high-power pulsed and low-power continous wave (CW)), tert-butoxide anion, trapped in a pulsed ICR spectrometer, decomposes to yield acetone enolate anion and methane.The mechanism of this formal 1,2-elimination reaction was probed by measuring hydrogen isotope effects (both primary and secondary) in the IR laser photolysis of 2-methyl-2-propoxide-1,1,1-d3 (1) and 2-methyl-2-propoxide-1,1,1,3,3,3-d6 (2) anions.Unusually large secondary isotope effects (pulsed laser, 1.9 for 1 and 1.7 for 2; cw laser, 8 for 1) and small primary isotope effects (pulsed laser, 1.6 for 1 and 2; cw laser, 2.0 for 1) were observed.These isotope effects, particularly the large difference in energy dependence of the primary and secondary effects, are consistent only with a stepwise mechanism involving initial bond cleavage to an intermediate ion-molecule complex followed by a hydrogen transfer within the intermediate complex.The observed secondary isotope effects have been modelled by using statistical reaction rate (RRKM) theory.The implications of this study for several previously reported unimolecular ion decompositions are also discussed.
Silylated Sulfuric Acid: Preparation of a Tris(trimethylsilyl)oxosulfonium [(Me3Si?O)3SO]+ Salt
Bl?sing, Kevin,Labbow, Rene,Schulz, Axel,Villinger, Alexander
, p. 13798 - 13802 (2021)
The chemistry of silylated sulfuric acid, O2S(OSiMe3)2 (T2SO4, T=Me3Si; also known as bis(trimethylsilyl) sulfate), has been studied in detail with the aim of synthesizing the formal autosilylation products of silylated sulfuric acid, [T3SO4]+ and [TSO4]?, in analogy to the known protonated species, [H3SO4]+ and [HSO4]?. The synthesis of the [TSO4]? ion only succeeds when a base, such as OPMe3 that forms a weakly coordinating cation upon silylation, is reacted with T2SO4, resulting in the formation of [Me3POT]+[TSO4]?. [T3SO4]+ salts could be isolated starting from T2SO4 in the reaction with [T?H?T]+[B(C6F5)4]? or T+[CHB11Br6H5]? when a weakly coordinating anion is used as counterion. All silylated compounds could be crystallized and structurally characterized.
Tributyltin grafted onto the surface of 3-aminopropyl functionalized γ-Fe2O3 nanoparticles: A magnetically-recoverable catalyst for trimethylsilylation of alcohols and phenols
Nikbakht, Fatemeh,Ghonchepour, Ehsan,Ziyadi, Hakimeh,Heydari, Akbar
, p. 34428 - 34434 (2014)
Bonding of a homogenous tributyltin chloride catalyst on the surface of functionalized magnetic nanoparticles provides a new stable, efficient and magnetically recyclable catalyst for trimethylsilylation of alcohols and phenols with hexamethyldisilazan un
Organosilicon hypersilylchalcogenolates and related compounds
Lange, Heike,Herzog, Uwe,Borrmann, Horst,Walfort, Bernhard
, p. 4897 - 4908 (2004)
Reaction of potassium hypersilylchalcogenolates (Me3Si) 3SiEK (E = S, Se, Te) with organochlorosilanes R 4 - xSiClx (R = Me, Ph; x = 1-4) and methylchlorodisilanes (Si2Me5Cl, 1,2-Si2Me4Cl 2) yields organosilicon hypersilylchalcogenolates [(Me 3Si)3SiE]xSiR4 - x (x = 1-4) and [(Me3Si)3SiE]xSi2Me6 - x (x = 1, 2). A partial substitution product, [(Me3Si) 3SiSe]2SiPhCl (2) has been obtained by reaction of PhSiCl3 with 1.5 equivalents (Me3Si)3SiSeK. Besides characterization by 1H, 13C, 29Si, 77Se and 125Te NMR spectroscopy the compounds [(Me 3Si)3SiTe]2SiPh2 (1), [(Me 3Si)3SiSe]2SiPhCl (2) and [(Me 3Si)3SiSe]2Si2Me4 (3) have also been analyzed by crystal structure analyses. Reaction of potassium hypersilylchalcogenolates (Me3Si)3SiEK (E = S, Se, Te) with organochlorosilanes R4 - xSiClx (R = Me, Ph; x = 1-4) and methylchlorodisilanes (Si2Me5Cl, 1,2-Si 2Me4Cl2) yields organosilicon hypersilylchalcogenolates [(Me3Si)3SiE] xSiR4 - x (x = 1-4) and [(Me3Si) 3SiE]xSi2Me6 - x (x = 1, 2). A partial substitution product, [(Me3Si)3SiSe] 2SiPhCl (2) has been obtained by reaction of PhSiCl3 with 1.5 equivalents (Me3Si)3SiSeK. Besides characterization by 1H, 13C, 29Si, 77Se and 125Te NMR spectroscopy the compounds [(Me3Si) 3SiTe]2SiPh2 (1), [(Me3Si) 3SiSe]2SiPhCl (2) and [(Me3Si) 3SiSe]2Si2Me4(3) have also been analyzed by crystal structure analyses. Starting from (Me3Si) 5Si2K treatment with sulfur gave the highly branched potassium heptasilanylthiolate (Me3Si)5Si2SK. Reactions with methylchlorosilanes Me4 - xSiClx (x = 1, 2, 3) yielded organosilicon heptasilanylthiolates [(Me3Si) 3Si-(Me3Si)2Si-S]xSiMe 3 - x.
Bis(oligosilanyl)chalcogenides [Me3Si)xMe3-xSi]2E, alkalimetal oligosilanylchalcogenolates (Me3Si)xMe3-xSi-EMI and oligosilanylchalcogenols (Me3Si)xMe3-xSi-EH (E = S, Se, Te) syntheses and NMR study
Lange, Heike,Herzog, Uwe
, p. 36 - 42 (2002)
Bis(oligosilanyl)chalcogenides [(Me3Si)x Me3-x Si]2E, alkalimetal oligosilanylchalcogenolates (Me3Si)x Me3-x Si-EMI and oligosilanylchalcogenols (Me3Si)x Me3-x Si-EH (x=1-3; E=S, Se, Te) were synthesized and characterized by 1H-, 13C-, 29Si-, 77Se- and 125Te-NMR spectroscopy. Trends of NMR parameters (chemical shifts, coupling constants) are discussed.
Chemoselective silylation of alcohols
Bandgar,Wadgaonkar
, p. 2069 - 2074 (1997)
Hexamethyldisilazane (HMDS) in pesence of a catalytic amount of Envirocat EPZG silylates different alcohols in high yields with absolute chemoselectivity.
Novel protocol for the synthesis of organic ammonium tribromides and investigation of 1,1′-(Ethane-1,2-diyl)dipiperidinium bis(tribromide) in the silylation of alcohols and thiols
Dey, Rupa R.,Paul, Bappi,Dhar, Siddhartha S.,Bhattacharjee, Sushmita
, p. 1545 - 1547 (2014)
A novel and efficient protocol for the synthesis of organic ammonium tribromides (OATBs) is developed by using inexpensive and eco-friendly periodic acid as an oxidant for the conversion of Br-to Br3-. The method does not use any mineral acid and metal oxidants. The protocol is utilized to synthesize a new bis(tribromide) viz., 1,1′-(ethane-1,2-diyl)dipiperidinium bis(tribromide) (EDPBT). EDPBT is investigated as a catalyst in the silylation of alcohols and thiols by HMDS (hexamethyldisilazane) under solvent-free conditions.
Copper-Catalyzed Cross-Nucleophile Coupling of β-Allenyl Silanes with Tertiary C-H Bonds: A Radical Approach to Branched 1,3-Dienes
Shan, Qi-Chao,Hu, Lu-Min,Qin, Wei,Hu, Xu-Hong
supporting information, p. 6041 - 6045 (2021/08/03)
Described herein is a distinctive approach to branched 1,3-dienes through oxidative coupling of two nucleophilic substrates, β-allenyl silanes, and hydrocarbons appending latent functionality by copper catalysis. Notably, C(sp3)-H dienylation proceeded in a regiospecific manner, even in the presence of competitive C-H bonds that are capable of occurring hydrogen atom transfer process, such as those located at benzylic and other tertiary sites, or adjacent to an oxygen atom. Control experiments support the intermediacy of functionalized alkyl radicals.
Hydrogenolysis of Polysilanes Catalyzed by Low-Valent Nickel Complexes
Comas-Vives, Aleix,Eiler, Frederik,Grützmacher, Hansj?rg,Pribanic, Bruno,Trincado, Monica,Vogt, Matthias
supporting information, p. 15603 - 15609 (2020/04/29)
The dehydrogenation of organosilanes (RxSiH4?x) under the formation of Si?Si bonds is an intensively investigated process leading to oligo- or polysilanes. The reverse reaction is little studied. To date, the hydrogenolysis of Si?Si bonds requires very harsh conditions and is very unselective, leading to multiple side products. Herein, we describe a new catalytic hydrogenation of oligo- and polysilanes that is highly selective and proceeds under mild conditions. New low-valent nickel hydride complexes are used as catalysts and secondary silanes, RR′SiH2, are obtained as products in high purity.
The reaction of (tert-Butoxysilyl)methylmagnesium chlorides with some organotin and organosilicon monochlorides
Bykova, Irina A.,Kisin, Alexander V.,Monin, Evgeny A.,Nosova, Valentina M.,Philippov, Alexander M.,Storozhenko, Pavel A.
, (2020/04/15)
Interaction between (tert-butoxysilyl)methylmagnesium chlorides of the general formula Me3-n(t-BuO)nSiCH2MgCl, n = 1–3, with some organotin and organosilicon monochlorides has been studied. It has been found that the reaction of the Grignard reagents with trialkyltin chlorides readily proceeds via the methylene carbon with the formation of C-substituted products Me3-n(t-BuO)nSiCH2SnR3, R = Me, n-Bu in high yields. The path of this reaction with Me3SiCl and MePh2SiCl depends on the structure of Grignard compound and chlorosilane electrophilicity. Increasing the number of the tert-butoxy groups in the Grignard reagent has unexpectedly been found to result in the formation of Me3-n(t-BuO)nSiCH2OSiMeR2, R = Me, Ph and decrease of the organosilylmethyl silicon compounds content in the reaction products. The structure of the compounds synthesized has been confirmed by 1H, 13C, 29Si, 117,119Sn NMR spectroscopy and mass spectrometry.
