Addition of tris(trimethylsilyl)silyl radicals to the carbonyl group
作者:Angelo Alberti、Chryssostomos Chatgilialoglu
DOI:10.1016/s0040-4020(01)90531-9
日期:1990.1
The reactions of tris(trimethylsilyl)silyl radicals with somecompounds containing the carbonyl function (dialkyl or diaryl ketones and quinones) have been studied in solution by means of laser flash photolysis and ESR spectroscopy. The reactivities vary significantly with the nature of the substrate and the rate constants cover a range of four orders of magnitude. Overall tris(trimethylsilyl)silane
The sisyl (tris(trimethylsilyl)silyl) group: A fluoride resistant, photolabile alcohol protecting group
作者:Michael A. Brook、Christine Gottardo、Sonya Balduzzi、Mustafa Mohamed
DOI:10.1016/s0040-4039(97)01673-0
日期:1997.10
The use of the tris(trimethylsilyl)silyl (sisyl) group as a photolabile protecting group for primary and secondary alcohols was demonstrated. Sisyl ethers of a number of alcohols (yields 70-97%) were stable to many synthetic protocols, but could be deprotected using photolysis to give the starting alcohols (yields 62-95%). (C) 1997 Elsevier Science Ltd.
Alkoxyallylsilanes: Functional Protecting Groups
作者:Sonya Balduzzi、Michael A. Brook
DOI:10.1016/s0040-4020(99)01062-5
日期:2000.3
Allyl-t-butylmethylsilyl groups were shown to function as alcohol protecting groups whose hydrolytic stability was greater than t-butyldimethylsilyl (TBS) and Si(SiMe3)(3) (sisyl) groups. Pseudo-first-order rate constants for the acidic hydrolysis of primary, benzylic, and secondary allyl-t-butylmethylsilyl ethers in AcOD/THF-d(8)/D2O were determined to be 2.94x10(-3), 8.26x10(-4), and 8.26x10(-4)s(-1) respectively. The regioselectivity of acidic hydrolysis of allylbenzyloxy-t-butylmethylsilane 1 was examined under strong acid (p-TsOH/ CD2Cl2) and weak acid (AcOD/HF-d(8)/D2O) conditions. In both cases, benzyl alcohol was initially produced exclusively from silicon-oxygen bond cleavage: allylic cleavage was only subsequently observed over time. However, the allyl group of the silyl ether could be hydrosilylated. The resulting alkoxy-functionalized disiloxane had greater hydrolytic stability under acidic conditions than the starting alkoxyallyl-t-butylmethylsilane. (C) 2000 Elsevier Science Ltd. All rights reserved.