18938-24-4Relevant academic research and scientific papers
Supported gold nanoparticle-catalyzed cis -selective disilylation of terminal alkynes by σ disilanes
Gryparis, Charis,Kidonakis, Marios,Stratakis, Manolis
, p. 6038 - 6041 (2014/01/06)
Supported gold nanoparticles on metal oxides (1 mol %) catalyze for the first time the cis-selective disilylation of terminal alkynes by 1,2-disilanes in isolated yields up to 94%. It is likely that the reaction proceeds through oxidative insertion of the
Regio- and stereoselective approach to 1,2-di- and 1,1,2-trisilylethenes by cobalt-mediated reaction of silyl-substituted dibromomethanes with silylmethylmagnesium reagents
Ohmiya, Hirohisa,Yorimitsu, Hideki,Oshima, Koichiro
, p. 3488 - 3490 (2007/10/03)
(Chemical Equation Presented) Functional ethenes: Treatment of dibromo(silyl)methanes 2 a with silylmethyl Grignard reagents 1 and catalytic CoCl2 affords (E)-1,2-disilylethenes 3 a in excellent yields. Dibromodisilylmethanes 2 b undergo a simi
Episulfone substitution and ring-opening reactions via α-sulfonyl carbanion intermediates
Dishington, Allan P.,Douthwaite, Richard E.,Mortlock, Andrew,Muccioli, Adriano B.,Simpkins, Nigel S.
, p. 323 - 337 (2007/10/03)
Three-membered cyclic sulfones undergo substitution on treatment with base-electrophile mixtures, such as LDA-Me3SiCl and Bu′-P4 phosphazene base-PhCHO, to give either substituted episulfones or the corresponding alkenes following loss of SO2. The structure of a trisilylated episulfone product, 2a, was determined by X-ray crystallography. In the absence of Me3SiCl, reaction of episulfones with lithium diisopropylamide results in ring-opening to give alkenyl sulfinate intermediates, which can be alkylated to give (E)-alkenyl sulfone products in stereoselective fashion.
First Examples of Episulfone Substitution Reactions via α-Sulfonyl Carbanion Intermediates
Muccioli, Adriano B.,Simpkins, Nigel S.,Mortlock, Andrew
, p. 5141 - 5143 (2007/10/02)
Three-membered cyclic sulfones (episulfones) undergo substitution on treatment with base-electrophile mixtures, such as LDA-Me3SiCl and tBu-P4-phosphazene base-PhCHO, to give either substituted episulfones or the corresponding alkenes following loss of SO2.
Platinum-catalyzed elimination-addition reactions of trisilylethenes
Suzuki, Toshio,Lo, Peter Y.
, p. 27 - 33 (2007/10/02)
(E)-1-Hexyldimethylsilyl-1,2-bis(trimethylsilyl)ethene (1) and (E)-1-(3'-butyl-1',3'-tetramethyldisiloxanyl)-1,2-bis(trimethylsilyl)ethene (7) undergo isomerization-redistribution reactions catalyzed by platinum.Each of them is converted into its (Z)-isomer and ethenes bearing one trimethylsilyl group and two substituted silyl groups as major products.The proposed mechanism for the reactions involves a sequence of eliminations of hydrosilanes from the ethenes and re-addition to them.Oxygen greatly affects the reaction apparently accelerating anti-elimination of hydrosilanes.
New aspects of platinum-catalyzed hydrosilylation of disilylethynes II. Effects of oxygen and temperature
Suzuki, Toshio,Lo, Peter Y.
, p. 299 - 305 (2007/10/02)
It has been found that oxygen can markedly influence the outcome of the products from platinum-catalyzed reaction of Me3SiCCSiMe3 with n-C6H13Me2SiH or n-BuMe2SiOSiMe2H.Under dry air at 130 deg C, bis(trimethylsilyl)ethyne and hexyldimethylsilane apparently underwent silyl group exchange reactions to give trimethylsilane, hydrosilylation being a minor reaction.Products derived from oxidation reactions of SiH groups were also detected.With n-BuMe2SiOSiMeH hydrosilylation was a major reaction.With both hydrides, higher yields of normal adducts were obtained under nitrogen at 130 deg C than under dry air, though significant amounts of disilylethynes and isomers of the adducts were still produced.Under nitrogen at low temperature (90 deg C), the normal cis adducts were obtained in high yield, and these were isolated.Their structures were confirmed by selectively decopuled 29Si NMR.
New aspects of platinum-catalyzed hydrosilylation of disilylethynes
Suzuki, Toshio,Lo, Peter Y.
, p. 19 - 25 (2007/10/02)
The platinum-catalyzed hydrosilylations of bis(trimethylsilyl)ethyne and 1-trimethylsilylethynyl-1,1,3,3,5,5,7,7,7-nonamethyltetrasiloxane at 130-150 deg C were investigated using high molecular weight organosilicon hydrides.In addition to the expected adducts, significant amount of unexpected disilylethynes and trisilylethenes were produced.It is suggested that the reaction sequence involves elimination of silanes from the primary adducts to form disilylethynes and subsequent addition reactions to form various trisilylethenes.
Synthesis and Reactivity of a 1-Chloro-λ3-phosphirane
Niecke, Edgar,Leuer, Martina,Nieger, Martin
, p. 453 - 462 (2007/10/02)
dichlorophosphane (1) reacts with chlorobis(trimethylsilyl)methyllithium (2) to give 1-chloro-λ3-phosphirane 6.Nucleophilic substitution of the chlorine atom of 6 leads to a variety of derivatives 9a-n.In the case of bis(trimethylsilyl)amine the reaction does not provide the aminophosphirane 15 but to the isomeric phosphaalkene 16.However, 15 is accessible by reaction of the methylenphosphane 17 with 2.With an excess of nucleophile 9 is cleaved to give the phosphide 13 and tris(trimethylsilyl)ethen (10).Phosphirane 9f dissociates thermically to give 10 and chloromethylenephosphane 20.Reaction of 6 with methylenetriphenylphosphorane and 1,8-diazabicycloundec-7-ene (DBU) leads to substitution with formation of 22, 23 while with trimethylsilyl azide the product is an azidophosphirane 24. 1-Chlorophosphirane 6 reacts with AlCl3 to give the phosphirane complex 27.The molecular structure of 27 as well as the NMR data of the phosphiranes are discussed. - Keywords: 1-Chloro-2,2,3-tris(trimethylsilyl)phosphirane/ Phosphirane derivatives
ORGANIC SYNTHESIS WITH REAGENTS DERIVED FROM 3R3SiMgMe AND MnCl2
Fugami, Keigo,Hibino, Jun-ichi,Nakatsukasa, Shigeki,Matsubara, Seijiro,Oshima, Koichiro,et al.
, p. 4277 - 4292 (2007/10/02)
Synthetically useful reactions mediated by reagents derived from 3 equiv. of R3SiMgMe and MnCl2 are disclosed. (1) The manganese species reacted with terminal acetylenes to give 1,2-disilylated 1-alkenes.Mono- and bis(trimethylsilyl)acetylenes gave tri- a
Synthesis and Spectroscopic Characterization of Di- and Trisilylethenes
Schmidbaur, H.,Ebenhoech, J.
, p. 1543 - 1548 (2007/10/02)
Di- and trisilylethenes have been prepared by catalytic hydrosilylation of trimethylsilyl-, bis(trimethylsilyl)- and bis(trichlorosilyl)ethyne and converted into the hydrogenated derivatives by LiAlH4-reduction.The stereochemistry of the products and the effects of substitution of methyl vs. chlorine ligands on the NMR coupling constants J(29Si/1H) have been investigated by analysis of selectively (Me)-decoupled 29Si NMR spectra.From the results it has been concluded, that the catalytic hydrosilylation of silylated ethynes proceeds in a stereospecific syn fashion yield ing trans adducts.Substitution of methyl by chlorine at one or two Si-atoms in tris(trimethylsilyl)ethene leads to an increase of the coupling constant J(29Si/1H vinyl) with the chlorinated Si-atoms and reduces the values for those Si-atoms, where the methyl groups are retained. - Keywords: Di- and Trisilylethenes, Catalytic Hydrosilylation
