16343-18-3Relevant articles and documents
Dehydrocoupling of silanes catalyzed by zirconocene- and titanocene alkyne complexes
Peulecke, Normen,Thomas, Dominique,Baumann, Wolfgang,Fischer, Christine,Rosenthal, Uwe
, p. 6655 - 6656 (1997)
The zirconocene- and titanocene alkyne complexes 1-10 were tested to be effective catalysts in the dehydrocoupling of hydrosilanes like PhMeSiH2 and Ph2SiH2 to give oligomers and of other examples, e.g., PhSiH3
First synthesis of the three isomeric parent disilacyclohexanes. An improved preparation of methylene di-grignard
Gudnason, Palmar I.,Arnason, Ingvar
, p. 2015 - 2017 (2009)
Ring closure of 1,5-dibromo-1,5-disilapentane with methylene di-Grignard was the key step in the preparation of the parent 1,3-disilacyclohexane. For that purpose, the preparation of methylene di-Grignard has been improved and simplified. The successful s
Si-H bond activation at {(NHC)2Ni0} leading to hydrido silyl and bis(silyl) complexes: A versatile tool for catalytic Si-H/D exchange, acceptorless dehydrogenative coupling of hydrosilanes, and hydrogenation of disilanes to hydrosilanes
Schmidt, David,Zell, Thomas,Schaub, Thomas,Radius, Udo
, p. 10816 - 10827 (2014)
The unique reactivity of the nickel(0) complex [Ni2(iPr 2Im)4(COD)] (1) (iPr2Im = 1,3-di-isopropyl- imidazolin-2-ylidene) towards hydrosilanes in stoichiometric and catalytic reactions is reported. A series of nickel hydrido silyl complexes cis-[Ni(iPr2Im)2(H)(SiHn-1R4-n)] (n = 1, 2) and nickel bis(silyl) complexes cis-[Ni(iPr2Im) 2(SiHn-1R4-n)2] (n = 1, 2, 3) were synthesized by stoichiometric reactions of 1 with hydrosilanes H nSiR4-n, and fully characterized by X-ray diffraction and spectroscopic methods. These hydrido silyl complexes are examples where the full oxidative addition step is hindered. They have, as a result of the remaining Si-H interactions, remarkably short Si-H distances and feature a unique dynamic behavior in solution. Cis-[Ni(iPr2Im)2(H)(SiMePh 2)] (cis-5) shows in solution at room temperature a dynamic site exchange of the NHC ligands, H-D exchange with C6D6 to give the deuteride complex cis-[Ni(iPr2Im)2(D)(SiMePh 2)] (cis-5-D), and at elevated temperatures an irreversible isomerization to trans-[Ni(iPr2Im)2(D)(SiMePh 2)] (trans-5-D). Reactions with sterically less demanding silanes give cis-configured bis(silyl) complexes accompanied by the release of dihydrogen. These complexes display, similarly to the hydrido silyl complexes, interestingly short Si-Si distances. Complex 1 reacts with 4 eq. HSi(OEt) 3, in contrast to all the other silanes used in this study, to give the trans-configured bis(silyl) complex trans-[Ni(iPr2Im) 2Ni(Si(OEt)3)2] (trans-12). The addition of two equivalents of Ph2SiH2 to 1 results, at elevated temperatures, in the formation of the dinuclear complex [{(iPr 2Im)Ni-μ2-(HSiPh2)}2] (6). This diamagnetic, formal Ni(i) complex exhibits a long Ni-Ni bond in the solid state, as established by X-ray diffraction. The capability of the electron rich {Ni(iPr2Im)2} complex fragment to activate Si-H bonds was applied catalytically in the deuteration of Et3Si-H to Et 3Si-D employing C6D6 as a convenient deuterium source. Furthermore, we show that 1 serves as a catalyst for the acceptorless dehydrogenative coupling of Ph2SiH2 to the corresponding disilane Ph2HSi-SiHPh2 and trisilane Ph 2HSi-Si(Ph)2-SiHPh2, and the coupling of PhSiH3 to give a mixture of cyclic and linear polysilanes with high polydispersity (Mw = 1119; Mn = 924; Mw/M n = 1.2). The capability of 1 to catalyze the formal reverse reaction as well is demonstrated by the hydrogenation of disilanes. The hydrogenation of the disilanes Ph2MeSi-SiMePh2 and PhMe 2Si-SiMe2Ph to the corresponding hydrosilanes Ph 2MeSi-H and PhMe2Si-H, respectively, proceeds effectively in the presence of 1 under very mild conditions (room temperature, 1.8 bar H2 pressure).
Synthesis of Oligosilanes by Electrolysis of Hydrosilanes
Kimata, Yoshinori,Suzuki, Hiroshi,Satoh, Shin,Kuriyama, Akira
, p. 1163 - 1164 (1994)
The novel electrochemical reaction of hydrosilane compounds was investigated for the synthesis of polysilanes.The product obtained by electrolysis of Methylphenylsilane 1a was an oligosilane of Mn=454 (GPC) in 60percent yield, which consisted of Si-Si bonds for the main chain.When diphenylsilane was electrolyzed in a similar manner as 1a, the major product was a dimer in 23percent yield.
Pentamethylcyclopentadienyl-aminoborole derivatives of zirconium and hafnium with alkyl and allyl ligands
Pastor, Antonio,Kiely, Andrew F.,Henling, Lawrence M.,Day, Michael W.,Bercaw, John E.
, p. 65 - 75 (1997)
The preparations of new alkyl, iodo, and allyl derivatives of zirconium and hafnium with pentamethylcyclopentadienyl and aminoborole ancillary ligands are described. The dialkyl complexes Cp * {η5-C4H4BN(CHMe2)2}ZrR2Li (R = Me, C≡C-p-C6H4CH3, C≡CMe3, CH2Ph) are prepared from Cp * {η5-C4H4BN(CHMe2)2}ZrCl · LiCl and two equivalents of RLi. Cp * ZrI3 is prepared from Cp * ZrCl3 and BI3. Treatment of Cp * ZrI3 with Li2(THF){C4H4BN(CHMe2)2} yields Cp * (η5-C4H4BN(CHMe2)2}ZrI · LiI(THF). Treatment of Cp * (η5-C4H4BN(CHMe2)2}MCl · LiCl (M = Zr, Hf) with allyl magnesium bromide yields Cp * (η5-C4Me4BN(CHMe2)2}M(η3-C3H5) (M = Zr, Hf). Addition of donor ligands to Cp * (η5-C4H4BN(CHMe2)2}Hf(η3-C3H5) yields Cp * (η5-C4H4BN(CHMe2)2}Hf(η3-C3H5)(L) (L = PMe3, CO) and Cp * (η5-C4H4BN(CHMe2)2}Hf(η1-C3H5)(py). The results of X-ray structure determinations for Cp * (η5-C4H4BN(CHMe2)2}Hf(η3-C3H5) and Cp * (η5-C4H4BN(CHMe2)2}Hf(η3-C3H5)(CO) are reported.
Iridium Pincer Catalysts for Silane Dehydrocoupling: Ligand Effects on Selectivity and Activity
Mucha, Neil T.,Waterman, Rory
, p. 3865 - 3872 (2015)
Catalytic reactions of bisphosphinite pincer-ligated iridium compounds p-XR(POCOP)IrHCl (POCOP) [2,6-(R2PO)2C6H3, R = iPr, X = H (1); R = tBu, X = COOMe (2); = H (3); = NMe2 (4)] with primary and secondary silanes have been performed. Complex 1 is primarily a silane redistribution precatalyst, but dehydrocoupling catalysis is observed for sterically demanding silane substrates or with aggressive removal of H2. The bulkier compounds (2-4) are silane dehydrocoupling precatalysts that also undergo competitive redistribution with less hindered substrates. Products generated from reactions utilizing 2-4 include low molecular weight oligosilanes with varying degrees of redistribution present or disilanes when employing more sterically demanding silane substrates. Selectivity for redistribution versus dehydrocoupling depends on the steric and electronic environment of the metal but can also be affected by reaction conditions. (Chemical Equation Presented).
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.
Reactivity of the bis(silyl) palladium(II) complex toward organic isothiocyanates
Kim, Yong-Joo,Jeon, Hyung-Tak,Lee, Kyung-Eun,Lee, Soon W.
experimental part, p. 2258 - 2263 (2010/09/08)
The bis(silyl) palladium(II) complex [Pd(SiHPh2) 2(dmpe)] (dmpe = 1,2-bis(dimethylphosphino)ethane) reacted with organic isothiocyanates R-NCS (R = Ph, iPr, allyl) to give a dithiocarbonimidato [Pd(S2CN-Ph)(dmpe)] (1), a diphenylsilanedithiolato [Pd(S2SiPh2)(dmpe)] (2), or a π-allyl [(η3-allyl)Pd](NCS) (3) palladium complex, depending on the isothiocyanate type and reaction conditions. In addition, various dithiocarbonimidato Pd(II) complexes were also obtained from trans-[PdEt 2L2] (L = PMe3, PMe2Ph) (4-6) or [Pd(styrene)L2] and organic isothiocyanates.
Investigation of titanium-catalysed dehydrogenative coupling and hydrosilylation of phenylhydrogenosilanes in a one-pot process
Garcia, Julien,Meyer, Daniel J.M.,Guillaneux, Denis,Moreau, Jo?l J.E.,Wong Chi Man, Michel
experimental part, p. 2427 - 2433 (2009/09/30)
Titanium-catalysed dehydrocondensation and hydrosilylation of primary, secondary and tertiary phenylsilanes have been investigated in a one-pot process with Cp2Ti(OPh)2 as catalyst by NMR studies. Only primary and secondary silanes were found to undergo simultaneous dehydrogenative coupling and hydrosilylation reactions to produce the functional polysilanes.
Reactivity of group 4 benzamidinate complexes towards mono- and bis-substituted silanes and 1,5-hexadiene
Volkis, Victoria,Averbuj, Claudia,Eisen, Moris S.
, p. 1940 - 1950 (2007/10/03)
Zirconium and titanium bis(benzamidinate) dimethyl complexes were found to be active catalytic precursors for the oligomerization of mono- and bis-substituted silanes. The activation of such complexes, by an excess of MAO or by an equimolar amount of B(C
