Deprotection of Acetals and Silyl Ethers Using a Polymer-Supported π-Acid Catalyst: Chemoselectivity and Polymer Effect
作者:Nobuyuki Tanaka、Yukio Masaki
DOI:10.1055/s-1999-3000
日期:1999.12
A polymeric dicyanoketene acetal (DCKA), prepared from a styrene monomer bearing dicyanoketene acetal functionality, was found to be an effective and recyclable catalyst in the chemoselective deprotection of acetals and silyl ethers. A remarkable acceleration accountable for the polymer effect was observed.
A mild and efficient cleavage of tert-butyldimethylsilyl (TBS) and tetrahydropyranyl (THP) ethers using a catalytic amount of
作者:Yanfen Xu、Shouchu Tang、Junjie Han、Xuegong She、Xinfu Pan
DOI:10.1016/j.tetlet.2008.03.149
日期:2008.5
A mild and efficient method for the deprotection of the TBS and THP ethers is described. A wide variety of TBS ethers as well as THP ethers can be easily deprotected to the corresponding parent hydroxyl compounds by employing a catalytic amount of tris(4-bromophenyl)aminium hexachloroantimonate (TBPA(+center dot)SbCl(6)(-)) in methanol at room temperature in good yield. (C) 2008 Elsevier Ltd. All rights reserved.
Selective de-protection of silyl ethers
作者:Chandra Prakash、Samir Saleh、Ian A. Blair
DOI:10.1016/s0040-4039(01)80311-7
日期:——
The “Aqueous” Prins Reaction
作者:Danielle L. Aubele、Christopher A. Lee、Paul E. Floreancig
DOI:10.1021/ol0359259
日期:2003.11.1
are employed as oxocarbenium ion progenitors and allylsilanes are used as nucleophiles. Cyclizations proceed efficiently inside Lewis acidic micelles in water, demonstrating that colloidal suspensions can protect highly electrophilic intermediates from hydrolysis. Reactions are experimentally facile and useful in the preparation of a variety of vinyl- and aryl-substituted tetrahydropyrans with excellent