994-49-0Relevant articles and documents
Anderson, H. H.
, p. 196 - 197 (1950)
Ga+-catalyzed hydrosilylation? about the surprising system Ga+/HSiR3/olefin, proof of oxidation with subvalent Ga+and silylium catalysis with perfluoroalkoxyaluminate anions
Barthélemy, Antoine,Glootz, Kim,Hanske, Annaleah,Krossing, Ingo,Scherer, Harald
, p. 439 - 453 (2022/01/22)
Already 1 mol% of subvalent [Ga(PhF)2]+[pf]- ([pf]- = [Al(ORF)4]-, RF = C(CF3)3) initiates the hydrosilylation of olefinic double bonds under mild conditions. Reactions with HSiMe3 and HSiEt3 as substrates efficiently yield anti-Markovnikov and anti-addit
Hydrosilylative reduction of carbon dioxide by a homoleptic lanthanum aryloxide catalyst with high activity and selectivity
Chang, Kejian,Maron, Laurent,Xu, Xin,Zheng, Xizhou,del Rosal, Iker
supporting information, p. 7804 - 7809 (2021/06/16)
An efficient tandem hydrosilylation of CO2, which uses a combination of a simple, homoleptic lanthanum aryloxide and B(C6F5)3, was performed. Use of a less sterically hindered silane led to an exclusive reduction of CO2to CH4, with a turnover frequency of up to 6000 h?1at room temperature. The catalytic system is robust, and 19?400 turnovers could be achieved with 0.005 mol% loading of lanthanum. The reaction outcome depended highly on the nature of the silane reductant used. Selective production of the formaldehyde equivalent,i.e., bis(silyl)acetal, without over-reduction, was observed when a sterically bulky silane was used. The reaction mechanism was elucidated by stoichiometric reactions and DFT calculations.
Catalytic CO2 hydrosilylation with [Mn(CO)5Br] under mild reaction conditions
García, Juventino J.,González, Tania
supporting information, (2021/06/07)
Carbon dioxide hydrosilylation with earth-abundant transition-metal catalysts is an attractive alternative for the design of greener and cost-effective synthetic strategies. Herein, simple [Mn(CO)5Br] is an efficient precatalyst in the hydrosilylation of carbon dioxide with Et3SiH under mild reaction conditions. Using THF as a solvent, triethylsilylformate Et3SiCH(O)O was obtained in 67% yield after 1 h at 50 °C and 4 bar of CO2 pressure. The selectivity of the reaction was tuned by changing the solvent to a mixture of THF and toluene producing bis(triethylsilyl)acetal (Et3SiO)2CH2 in 86% yield. The CO2 hydrosilylation was also effective at room temperature and atmospheric pressure using either THF or the mixture THF/toluene as the solvent resulting in high Et3SiH conversion (92%–99%) but with a decrease in the selectivity. Radical trapping experiments indicated the participation of radical species in the catalytic mechanism. To the best of our knowledge, this is the first report on CO2 hydrosilylation catalyzed by transition-metal radical intermediates.
