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
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).
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.
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.
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.
