61518-55-6Relevant academic research and scientific papers
Markovnikov Hydrosilylation of Alkynes with Tertiary Silanes Catalyzed by Dinuclear Cobalt Carbonyl Complexes with NHC Ligation
Deng, Liang,Lai, Yuhang,Leng, Xuebing,Wang, Dongyang,Wang, Peng,Xiao, Jie
supporting information, p. 12847 - 12856 (2021/08/24)
Metal-catalyzed hydrosilylation of alkynes is an ideal atom-economic method to prepare vinylsilanes that are useful reagents in the organic synthesis and silicone industry. Although great success has been made in the preparation of β-vinylsilanes by metal-catalyzed hydrosilylation reactions of alkynes, reported metal-catalyzed reactions for the synthesis of α-vinylsilanes suffer from narrow substrate scope and/or poor selectivity. Herein, we present selective Markovnikov hydrosilylation reactions of terminal alkynes with tertiary silanes using a dicobalt carbonyl N-heterocyclic carbene (NHC) complex [(IPr)2Co2(CO)6] (IPr = 1,3-di(2,6-diisopropylphenyl)imidazol-2-ylidene) as catalyst. This cobalt catalyst effects the hydrosilylation of both alkyl- and aryl-substituted terminal alkynes with a variety of tertiary silanes with good functional group compatibility, furnishing α-vinylsilanes with high yields and high α/β selectivity. Mechanistic study revealed that the stoichiometric reactions of [(IPr)2Co2(CO)6] with PhCCH and HSiEt3 can furnish the dinuclear cobalt alkyne and mononuclear cobalt silyl complexes [(IPr)(CO)2Co(μ-ν2:ν2-HCCPh)Co(CO)3], [(IPr)(CO)2Co(μ- ν2:ν2-HCCPh)Co(CO)2(IPr)], and [(IPr)Co(CO)3(SiEt3)], respectively. Both dicobalt bridging alkyne complexes can react with HSiEt3 to yield α-triethylsilyl styrene and effect the catalytic Markovnikov hydrosilylation reaction. However, the mono(NHC) dicobalt complex [(IPr)(CO)2Co(μ- ν2:ν2-HCCPh)Co(CO)3] exhibits higher catalytic activity over the di(NHC)-dicobalt complexes. The cobalt silyl complex [(IPr)Co(CO)3(SiEt3)] is ineffective in catalyzing the hydrosilylation reaction. Deuterium labeling experiments with PhCCD and DSiEt3 indicates the syn-addition nature of the hydrosilylation reaction. The absence of deuterium scrambling in the hydrosilylation products formed from the catalytic reaction of PhCCH with a mixture of DSiEt3 and HSi(OEt)3 hints that mononuclear cobalt species are less likely the in-cycle species. These observations, in addition to the evident of nonsymmetric Co2C2-butterfly core in the structure of [(IPr)(CO)2Co(μ- ν2:ν2-HCCPh)Co(CO)3], point out that mono(IPr)-dicobalt species are the genuine catalysts for the cobalt-catalyzed hydrosilylation reaction and that the high α selectivity of the catalytic system originates from the joint play of the dicobalt carbonyl species to coordinate alkynes in the Co(μ- ν2:ν2-HCCR′)Co mode and the steric demanding nature of IPr ligand.
Solvent-free hydrosilylation of alkenes and alkynes using recyclable platinum on carbon nanotubes
Jawale, Dhanaji V.,Geertsen, Valérie,Miserque, Frédéric,Berthault, Patrick,Gravel, Edmond,Doris, Eric
, p. 815 - 820 (2021/02/09)
Platinum nanoparticles were stabilized at the surface of carbon nanotubes and the nanohybrid was valorized as a catalyst for the hydrosilylation of alkenes and alkynes. The heterogeneous catalyst operated under sustainable conditions (room temperature, no solvent, low catalyst loading, air atmosphere) and exhibited improved stabilty as recycling and reuse could be achieved for multiple consecutive reactions.
Waste-free and efficient hydrosilylation of olefins
Pandarus, Valerica,Ciriminna, Rosaria,Gingras, Geneviève,Béland, Fran?ois,Kaliaguine, Serge,Pagliaro, Mario
, p. 129 - 140 (2019/01/11)
High purity silicone precursors can now be synthesized by hydrosilylation of solvent-free olefins catalyzed by a highly stable and active glass hybrid catalyst consisting of mesoporous organosilica microspheres doped with Pt nanoparticles. These findings open the door to the sustainable manufacture of silicone and a way to further reduce the amount of platinum in silicones, which are ubiquitous advanced polymers with multiple uses and applications.
Direct Silyl-Heck Reaction of Chlorosilanes
Matsumoto, Kazuhiro,Huang, Jiadi,Naganawa, Yuki,Guo, Haiqing,Beppu, Teruo,Sato, Kazuhiko,Shimada, Shigeru,Nakajima, Yumiko
supporting information, p. 2481 - 2484 (2018/04/27)
A nickel complex/Lewis acid combination effectively catalyzed the direct silyl-Heck reaction of chlorosilanes, which are key raw materials in the organosilicon industry, to give synthetically important alkenylsilane products. Trichlorosilanes, dichlorosil
Styrylsilane coupling reagents for immobilization of organic functional groups on silica and glass surfaces
Kim, Soo-Bin,Lee, Chang-Hee,Jun, Chul-Ho
supporting information, p. 9961 - 9964 (2018/09/10)
Styrylsilanes serve as new coupling reagents for introducing organic functional groups on silica and glass surfaces. Functionalized styrylsilanes, which are readily prepared via catalytic hydrosilylation of the corresponding phenylacetylenes with silanes, are immobilized on silica through acid catalyzed processes under mild conditions.
Functionalized vinylsilanes via highly efficient and recyclable Pt-nanoparticle catalysed hydrosilylation of alkynes
Chauhan, Bhanu P. S.,Sarkar, Alok
, p. 8709 - 8715 (2017/07/24)
A mild, selective and facile synthesis of vinylsilanes via a recyclable platinum nanoparticle catalysed hydrosilylation of alkynes is reported. Various functionalized alkynes are selectively hydrosilylated to furnish functional β-E vinylsilanes in high yi
Regioselectivity of Stoichiometric Metathesis of Vinylsilanes with Second-Generation Grubbs Catalyst: A Combined DFT and Experimental Study
?liwa, Pawe?,Kurleto, Kamil,Handzlik, Jaros?aw,Rogalski, Szymon,Zak, Patrycja,Wyrzykiewicz, Bozena,Pietraszuk, Cezary
supporting information, p. 621 - 628 (2016/03/25)
The regioselectivity of metathesis reactions of trisubstituted vinylsilanes H2C=CHSiR3 (SiR3 = SiCl3, SiCl2Me, SiClMe2, SiMe3, Si(OEt)3) with the second-generation rut
Competitive acylation of arylstyrylsilanes: Controlling silanucleophile reactivity
Brook, Michael A.,Henry, Courtney
, p. 861 - 868 (2007/10/03)
Electrophilic substitution reactions occurred cleanly between acyl cations and arylstyrylsilanes 2-4. With an unsubstituted aryl group, 2 underwent transfer of the styryl group to form styryl ketone 5 as would be predicted from previous kinetic studies. With increasing methyl group substitution of the aryl group, aryl group transfer occurred competitively such that 3 showed a 2:1 preference for destyrylation: dearylation giving 10:11 while 4 underwent exclusive transfer of the mesityl group to give mesityl ketones 6-8. These results are not consistent with electrophilic aromatic substitution reactions of nonsilylated compounds. With increasing methyl group substitution of the aryl group, its reactivity should increase for electronic reasons but not to the extent that is surpasses that of the styryl group. When the silyl group is flanked by methyl groups, however, cleavage of the silicon-aryl bond is additionally facilitated by the relief of steric congestion such that this process occurs preferentially to transfer of the styryl group.
Transition Metal Complexes of Troeger's Base and their Catalytic Activity for the Hydrosilylation of Alkynes
Goldberg, Yuri,Alper, Howard
, p. 369 - 372 (2007/10/02)
Rhodium(III) and iridium(III) complexes of Troeger's base (TB), of structural type TB*2MCl3 (M=Rh, Ir), were prepared by treatment of TB with MCl3.The rhodium complex readily catalyzed the hydrosilylation of alkynes with high regio- and stereoselectively observed in some cases.
