diastereoselective radical 1,5 phenylmigration reactions fromsilicon in diarylsilyl ethers to various C-centered radicals to form the corresponding 3-phenylated alcohols are described. Functionalized aryl groups can also be transferred. The effect of the variation of the attacking radical on the aryl transfer reaction is discussed. Best results are obtained for the phenylmigration to nucleophilic secondary
Remote Control of Diastereoselectivity in Intramolecular Reactions of Chiral Allylsilanes
作者:Weston R. Judd、Sooho Ban、Jeffrey Aubé
DOI:10.1021/ja063411+
日期:2006.10.1
During investigations of cyclization reactions between chiral allylsilanes and N-acyliminiumions, it was discovered that a suitably positioned benzyloxy group on the allylsilane component caused a reversal in the diastereoselectivity of these reactions relative to that normally observed with alkyl-substituted allylsilanes. This effect was subsequently observed in two other reaction types. Investigations
Synthesis of Biaryls by Intramolecular Radical Aryl Migration from Silicon to Carbon
作者:Armido Studer、Martin Bossart、Tomaso Vasella
DOI:10.1021/ol005661f
日期:2000.4.1
A new method for the preparation of biaryls via intramolecular 1,5 aryl migration reaction from silicon in silyl ethers to arylradicals is presented. Various readily available diphenylsilyl ethers can be used as substrates in this reaction. Functionalized aryl groups can also be transferred. The analogous 1,4 aryl migration reaction is less efficient.
Stereoselective Synthesis of Highly Enantioenriched (E)-Allylsilanes by Palladium-Catalyzed Intramolecular Bis-Silylation: 1,3-Chirality Transfer and Enantioenrichment via Dimer Formation
作者:Michinori Suginome、Taisuke Iwanami、Yutaka Ohmori、Akira Matsumoto、Yoshihiko Ito
DOI:10.1002/chem.200401031
日期:2005.1
Highly enantioenriched (E)-allylsilanes have been synthesized from optically active allylicalcohols on the basis of Pd-catalyzed intramolecularbis-silylation followed by highly stereospecific Si-O elimination reactions. The method involves three steps: 1) O-disilanylation of the allylicalcohols with chlorodisilanes, 2) intramolecularbis-silylation in the presence of a 1,1,3,3-tetramethylbutyl
The nickel-catalyzed reactions of 2-phenyl- and 2-(o-tolyl)-2-(phenylethynyl)hexamethyltrisilane (I and II) with phenyl(trimethylsilyl)acetylene at 180°C have been examined. The reaction of I with phenyl(trimethylsilyl)acetylene in the presence of tetrakis(triethylphosphine)nickel(0) gave 1,3-diphenyl-2-[phenyl(trimethylsilyl)methylene]-1,4-bis(trimethylsilyl)-1-silacyclobut-3-ene and 1,4,4-trimethyl-1