A remarkable solvent effect toward the Pd/C-catalyzed cleavage of silyl ethersElectronic supplementary information (ESI) available: characterization data and references and supplementary Tables 4 and 5. See http://www.rsc.org/suppdata/cc/b2/b211313a/
We developed an efficient method for the silylation of alcohols using anilinosilane with tetrabutylammonium fluoride (TBAF) catalyst, wherein TMS, TES and TBS groups were smoothly introduced into silylation-resistant hindered alcohols under mild conditions.
Versatile Dehydrogenative Alcohol Silylation Catalyzed by Cu(I)−Phosphine Complex
作者:Hajime Ito、Akiko Watanabe、Masaya Sawamura
DOI:10.1021/ol050559+
日期:2005.4.1
[reaction: see text] Cu(I) complexes of xanthane-based diphosphines were versatile catalysts for dehydrogenative alcohol silylation, exhibiting high activity and broad substrate scope. Highlyselectivesilylation of 1-decanol over 2-decanol is possible even with a silylating reagent of small steric demand such as HSiMe(2)Ph or HSiEt(3).
Mechanistic studies on the hydrosilylation of an acetylene cobalt complex; trapping an active catalyst Co2(CO)6 causing olefin-isomerization and O-silylation
reported a hydrosilylation reaction of acetylenecobaltcomplexes to produce the corresponding vinylsilanes. It has become clear that olefin-isomerization and O-silylation occurred under some hydrosilylation conditions. To avoid these side reactions, we found that hydrosilylation should be carried out in the presence of bis(trimethylsilyl)acetylene. The Co2(CO)6, which would cause side reactions, migrates
Facile Cleavage of Triethylsilyl (TES) Ethers Using <i>o</i>-Iodoxybenzoic Acid (IBX) without Affecting <i>tert</i>-Butyldimethylsilyl (TBS) Ethers
作者:Yikang Wu、Jia-Hui Huang、Xin Shen、Qi Hu、Chao-Jun Tang、Liang Li
DOI:10.1021/ol025946n
日期:2002.6.1
[GRAPHICS]In DMSO cleavage of triethylsilyl (TES) ethers by o-iodoxybenzoic acid (IBX) was significantly faster than cleavage of tart-butyldimethylsilyl (TBS) ethers or further oxidation into carbonyl compounds. In most cases, TES protecting groups could be removed in good to excellent yields within 1 h, whereas similar TBS protecting groups remained intact under the same conditions. The procedure also could be adapted for direct one-pot conversion of TES ethers into carbonyl compounds.
Solvent-modulated Pd/C-catalyzed deprotection of silyl ethers and chemoselective hydrogenation
Recently we have reported undesirable and frequent deprotection of the TBDMS protective group of a variety of hydroxyl functions occurred under neutral and mild hydrogenation conditions using 10% Pd/C in MeOH. The deprotection of silyl ethers is susceptible to significant solvent effect. TBDMS and TES protecting groups were selectively cleaved in the presence of acid-sensitive functional groups such as TIPS ether, TBDPS ether and dimethyl acetal under hydrogenation condition using 10% Pd/C in MeOH. In contrast, chemoselective hydrogenation of reducible functional groups such as acetylene, olefin and benzyl ether, proceeds in the presence of TBDMS or TES ethers in AcOEt or MeCN. (C) 2004 Elsevier Ltd. All rights reserved.