Inspired by homogeneous borane catalysts that promote Si-H bond activation, we herein describe an innovative method for surface modification of silica using hydrosilanes as the modification precursor and tris(pentafluorophenyl)borane (B(C6F5)3) as the catalyst. Since the surface modification reaction between surface silanol and hydrosilane is dehydrogenative, progress and termination of the reaction
Oligosaccharide Analogues of Polysaccharides. Part 3. A new protecting group for alkynes: Orthogonally protected dialkynes
作者:Chengzhi Cai、Andrea Vasella
DOI:10.1002/hlca.19950780319
日期:1995.5.10
hydroxysulfide 16 with 15. The OH group of 27 was protected to yield the [dimethyl(oxy)propyl]dimethylsilyl}acetylenes (DOPSA's) 21, 28, and 29. The orthogonallyprotected acetylenes 20–22, 28, and 29 were de-trimethylsilylated to the new monoprotected acetylene synthons 30–34. The scope of the orthogonal protection was checked by regioselective deprotection of the dialkynes 39–42 (Scheme 4), prepared by alkylation
通过在质子溶剂中(4)用碱处理,或在暴露OH基团之后,在质子惰性溶剂中用催化量的碱(5和8)处理3型二元炔(方案1)的区域选择性脱保护。在ME 3的Si-保护12(方案2)是惰性的催化丁基锂/ THF其转化11到9,而ķ 2 CO 3 / MeOH中转化的两个10到9,和12到13,表明需要更受阻的(羟丙基)甲硅烷基取代基。17–19(方案3)中的碳负离子的C-甲硅烷基化反应生成15的碳负离子导致20-22,但以合理的收率仅获得22。因此,关键中间体27是通过逆布鲁克重排23制备的,该逆向布鲁克重排是通过将羟基硫化物16与15进行甲硅烷基化而制得的。OH基团的27是受保护的,得到[ d imethyl(氧)p丙基]二甲基甲硅烷}乙炔(DOPSA的)21,28和29。正交保护的乙炔20–22、28和29被去三甲基甲硅烷基化为新的单保护的乙炔合成子30–34。正交的保护范围是由dialkyn
[EN] PROCESS FOR SYNTHESIS OF ORGANOSILICON COMPOUNDS FROM HALOSILANES<br/>[FR] PROCÉDÉ DE SYNTHÈSE DE COMPOSÉS D'ORGANOSILICIUM À PARTIR D'HALOSILANES
申请人:MOMENTIVE PERFORMANCE MAT INC
公开号:WO2022026307A1
公开(公告)日:2022-02-03
A process for synthesis of an organosilicon compound is provided herein. Also, novel organosilicon compounds prepared by the present process is provided herein. The process comprises the reaction of a halosilane with an organofunctional alkyl halide in the presence of a metal catalyst, a promoter, and an optional co-catalyst. The process provides an efficient synthetic route to produce organosilicon compounds. The process also allows synthesis of organosilicon compounds with a plurality of different functional groups.
Mechanistic insights into the hydrosilylation of allyl compounds – Evidence for different coexisting reaction pathways
作者:Peter Gigler、Markus Drees、Korbinian Riener、Bettina Bechlars、Wolfgang A. Herrmann、Fritz E. Kühn
DOI:10.1016/j.jcat.2012.06.006
日期:2012.11
The hydrosilylation of allyl compounds is often accompanied by the formation of high amounts of byproducts. The formation processes have not been fully understood so far. In this work, the allyl hydrosilylation mechanism is investigated in detail and experimental and theoretical evidence for multiple, coexisting reaction pathways is provided. Based on earlier reports and the observations during an extensive catalytic study, different pathways, leading to the observed byproducts, were identified and proven by labeling experiments and DFT calculations. Oxidative addition of the silane and the insertion of the allyl compound into the Pt-H bond turned out to be the crucial, selectivity-determining steps within the catalytic cycle. Based on these findings, it should be possible to systematically influence these steps and pave the way to a rational and straightforward design of more selective catalysts. (C) 2012 Published by Elsevier Inc.