17877-23-5Relevant academic research and scientific papers
Novel Si(II)+and Ge(II)+Compounds as Efficient Catalysts in Organosilicon Chemistry: Siloxane Coupling Reaction ?
Fritz-Langhals, Elke,Kneissl, Sotirios,Piroutek, Phillip,Werge, Sven
, (2020/09/02)
Novel catalytically active cationic Si(II) and Ge(II) compounds were synthesized and isolated in pure form. The Ge(II)+-based compounds proved to be stable against air and moisture and therefore can be handled very easily. All compounds efficiently catalyze the oxidative coupling of hydrosil(ox)anes with aldehydes and ketones as oxidation reagents and simultaneously the reductive ether coupling at very low amounts of 0.01 mol %. Because the catalysts also catalyze the reversible cyclotrimerization of aldehydes, paraldehyde can be used as a convenient source for acetaldehyde in siloxane coupling. It is shown that the reaction is especially suitable to make siloxane copolymers. Moreover, a new fluorine-free weakly coordinating boronate anion, B(SiCl3)4-, was successfully combined with the Si(II) and Ge(II) cations to give the stable catalytically active ion pairs Cp*Si:+B(SiCl3)4-, Cp*Ge:+B(SiCl3)4-, and [Cp(SiMe3)3Ge:+]B(SiCl3)4-.
Unanticipated Silyl Transfer in Enantioselective α,β-Unsaturated Acyl Ammonium Catalysis Using Silyl Nitronates
Matviitsuk, Anastassia,Greenhalgh, Mark D.,Taylor, James E.,Nguyen, Xuan B.,Cordes, David B.,Slawin, Alexandra M. Z.,Lupton, David W.,Smith, Andrew D.
supporting information, p. 335 - 339 (2020/01/11)
The use of silyl nitronates is reported for the isothiourea-catalyzed synthesis of ?3-nitro-substituted silyl esters containing up to two contiguous stereocenters in good yields with excellent enantioselectivities (up to 93% yield and 99:1 er). The serendipitously discovered formation of silyl ester products in this reaction demonstrates a novel platform for catalyst turnover in α,β-unsaturated acyl ammonium catalysis.
Synthesis and reactions of donor cyclopropanes: efficient routes to cis- and trans-tetrahydrofurans
Dunn, Jonathan,Dobbs, Adrian P.
supporting information, p. 7386 - 7414 (2015/08/24)
Abstract A detailed study on the synthesis and reactions of silylmethylcyclopropanes is reported. In their simplest form, these donor-only cyclopropanes undergo Lewis acid promoted reaction to give either cis- or trans-tetrahydrofurans, with the selectivity being reaction condition-dependant. The adducts themselves are demonstrated to be an important scaffold for structural diversification. The combination of a silyl-donor group in a donor-acceptor cyclopropane with novel acceptor groups is also discussed.
An efficient catalytic approach for the synthesis of unsymmetrical siloxanes
Hreczycho, Grzegorz
, p. 67 - 72 (2015/01/30)
The potential for expanding the variety of catalytic methods for siloxane bond formation is explored. Alkoxysilanes react with methylallylsilanes in the presence of scandium(III) trifluoromethanesulfonate to yield disiloxanes and isobutene. The reaction p
Nonhydrolytic synthesis of silanols by the hydrogenolysis of benzyloxysilanes
Igarashi, Masayasu,Matsumoto, Tomohiro,Sato, Kazuhiko,Ando, Wataru,Shimada, Shigeru
supporting information, p. 429 - 431 (2014/04/17)
The hydrogenolysis of benzyloxysilanes was smoothly catalyzed by Pd/C in THF to give corresponding silanols under nonhydrolytic conditions. The reaction proved to be applicable to various benzyloxysilanes giving silanemonools, diol, and triol.
Catalytic hydrogen evolution from hydrolytic oxidation of organosilanes with silver nitrate catalyst
Teo, Alan Kay Liang,Fan, Wai Yip
, p. 37645 - 37648 (2014/11/27)
In the light of uncertainty over the amount of recoverable fossil fuel reserves, hydrogen is touted to be a promising energy carrier in the future. Nevertheless, hydrogen storage remains a daunting challenge but a potential reaction for the generation of hydrogen on demand is the hydrolytic oxidation of organosilanes. Here, we demonstrate that silver nitrate, a readily available ionic salt, can catalyze the hydrolysis of organosilanes to produce hydrogen and organosilanols. In particular, turnover numbers and turnover frequencies in excess of 5 × 103 and 102 min-1 respectively are obtainable for the hydrolysis of triethylsilane at room temperature. This proposed silver nitrate mediated system is, by far, the simplest and cheapest catalytic hydrolysis of organosilanes. Results from the kinetic studies suggested a mechanistic scenario in which the hydrolysis of organosilanes is third order overall and first order in organosilane, water, and catalyst. The high hydrogen yield observed makes the silver nitrate catalyst an attractive material for hydrogen evolution. the Partner Organisations 2014.
Di- tert -butylisobutylsilyl, another useful protecting group
Liang, Huan,Hu, Lin,Corey
scheme or table, p. 4120 - 4123 (2011/10/04)
The di-tert-butylisobutylsilyl (BIBS) protecting group offers new possibilities for synthetic processes because of its steric bulk, robustness of its derivatives, and other special properties.
Synthesis of polyketides via diastereoselective acetalization
Shepherd, Jennifer N.,Myles, David C.
, p. 1027 - 1030 (2007/10/03)
(Matrix presented) Diastereoselective acetalization of pseudo-C 2-symmetric 1,3,5-triol systems is a general strategy for the rapid generation of polyketides. The oxidative acetalization reaction shown above was studied under both kinetic and t
