- Nano-dispersed platinum(0) in organically modified silicate matrices as sustainable catalysts for a regioselective hydrosilylation of alkenes and alkynes
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Nano-dispersed platinum(0) particles stabilized in a range of organically modified silicate (ORMOSIL) matrices are investigated as sustainable catalysts for the hydrosilylation of alkenes and alkynes. In this study, five different siloxane matrices including triethoxysilane (HTEOS), methyltriethoxysilane (MTES), ethyltriethoxysilane (ETES), triethoxyvinylsilane (TEVS) and propyltriethoxysilane (PTES) are investigated, and the distribution of the metal particles in these materials analyzed by transition electron microscopy (TEM). The particles appeared to be generally of a small size, with a diameter of ca. 2-5 nm in each of these catalysts, however the distribution is not equally uniform from one matrix to the other. HTEOS, MTES and ETES that respectively carry a hydrogen, a methyl and an ethyl group on the triethoxysilane moiety, displayed a more uniform distribution, while particles appeared to be more scattered in the remaining matrices. Catalysts with a uniform particles distribution produced higher and consistent yields, while those with poor particles distribution produced lower and almost random yields, suggesting that the uniformity in particle distribution, and by extension the nature of the siloxane matrix, are important for the catalytic properties of these materials. The scope of the reaction was broadened to a range of olefins, with a goal of investigating the tolerability of the reaction toward a number of reactive functional groups, resulting in the preparation of 28 compounds. This catalytic system also enabled the hydrosilylation of a limited number of alkynes under the optimized reaction conditions.
- Duke, Brett J.,Akeroyd, Evan N.,Bhatt, Shreeja V.,Onyeagusi, Chibueze I.,Bhatt, Shreya V.,Adolph, Brandy R.,Fotie, Jean
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p. 11782 - 11795
(2018/07/25)
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- Tandem Hydrosilylation/o-C-H Silylation of Arylalkynes Catalyzed by Ruthenium Bis(silyl) Aminophosphine Complexes
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An unprecedented reaction via consecutive trans-selective hydrosilylation and o-C-H silylation of arylalkynes with hydrosilanes was developed by use of ruthenium complex catalysts Ru{?°3(Si,O,Si)-xantsil}(CO)(PR3) (R = NC4H8 (1-Pyrr), NC5H10 (1-Pip); xantsil = (9,9-dimethylxanthene-4,5-diyl)bis(dimethylsilyl)). This reaction proceeded with gentle heating at 40-60 °C and afforded novel 2,α-bis-silylated (Z)-stilbene or (Z)-styrene derivatives 2 together with an equimolar amount of (E)-/(Z)-arylalkenes as byproducts. The selectivity of the formation of 2 reached a maximum by employing catalyst 1-Pyrr ligated by the less bulky triaminophosphine P(NC4H8)3 and hydrosilane HSiMe(OSiMe3)2 having moderately bulky and electron withdrawing substituents.
- Kitano, Takeo,Komuro, Takashi,Ono, Rikima,Tobita, Hiromi
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supporting information
p. 2710 - 2713
(2017/08/21)
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- Bis(acetylacetonato)Ni(II)/NaBHEt3-catalyzed hydrosilylation of 1,3-dienes, alkenes and alkynes
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The utility of commercially available Ni(II) salts, Ni(acac)2 (acac = acetylacetonato) (1a) and its derivatives bis(hexafluoroacetylacetonato)nickel(II) (1b) and bis(2,2,6,6-tetramethyl-3,5-heptanedionato)nickel(II) (1c) as versatile hydrosilylation catalyst precursors is described. Complexes 1a-c catalyze 1,4-selective hydrosilylation of 1,3-dienes in the presence of NaBHEt3 at ambient temperature. The reactions exhibit good regioselectivity to give the branched isomers as major products. The catalytic system also catalyzes hydrosilylation of alkenes including industriary important siloxy-, amino-, and epoxy-substituted ones as well as both terminal and internal alkynes.
- Srinivas, Venu,Nakajima, Yumiko,Ando, Wataru,Sato, Kazuhiko,Shimada, Shigeru
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- Rhodium-catalysed synthesis of multi-substituted silylindenes from aryl alkynes and hydrosilanes via C-H bond activation
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We successfully developed rhodium-catalysed synthesis of multi-substituted silylindenes from 2 equivalents of aryl alkynes and 1 equivalent of hydrosilanes in moderate to good yields via C-H bond activation for the first time. The silyl groups of the obta
- Sueki, Shunsuke,Kuninobu, Yoichiro
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supporting information
p. 7685 - 7688
(2015/05/27)
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- Stereodivergent formation of alkenylsilanes: syn or anti Hydrosilylation of alkynes catalyzed by a cyclopentadienylcobalt(I) chelate bearing a pendant phosphane tether
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The hydrosilylation of alkynes is catalyzed by the di-tert- butylphosphanylethylcyclopentadienyl-cobalt chelate 1. While the reaction of internal alkynes exclusively affords syn hydrosilylation products with triethylsilane, the reaction with triethoxysila
- Yong, Li,Kirleis, Karin,Butenschoen, Holger
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p. 833 - 836
(2007/10/03)
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- Platinum catalyzed hydrosilylation of alkynes: comparison of rates of addition of terminal olefins to internal alkynes
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The relative rates of platinum catalyzed hydrosilylation of terminal olefins versus internal alkynes were compared in competitive reactions. (EtO)3SiH added almost exclusively (97percent) to PhCCPh versus styrene.The reaction of (EtO)3SiH with equimolar amounts of 2-decyne and 1-hexene gave a 78:22 ratio of alkyne products 6/6' versus alkene product 7.The reaction of (EtO)3SiH with equimolar amounts of styrene and 1-phenyl-1-propyne gave a 78:22 ratio of alkyne products 10/10' to products 9.The silane, Me3SiOSiMe2H, reacted with equimolar amounts of 2-decyne and 1-hexene to give a 90:10 ratio of alkyne products 8/8' to alkene product 9.All of the products had E stereochemistry about the C=C double bond as determined by 29Si NMR (3J(Si-H)).
- Lewis, Larry N.,Sy, Karen G.,Donahue, Paul E.
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p. 165 - 172
(2007/10/02)
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