Metalation of alk-1-enes, using the mixture of butyllithium and potassium tert-butoxide in tetrahydropyran, followed by stereohomogenization and ultimate treatment with chlorotrimethylsilane afforded a series of alk-2-enyltrimethylsilanes in good yield and with (Z/E) ratios ranging from 95:5 to 98:2. The deprotonation of propene can be rapidly and readily accomplished with a stoichiometric amount of the superbase suspended in pentane on a 1 mol scale.
Nucleophilic <i>ortho</i>-Allylation of Pyrroles and Pyrazoles: An Accelerated Pummerer/Thio-Claisen Rearrangement Sequence
作者:Andrew J. Eberhart、Claudio Cicoira、David J. Procter
DOI:10.1021/ol401786d
日期:2013.8.2
Arylsulfinyl groups direct the metal-free, regiospecific, nucleophilic ortho-allylation of pyrroles and pyrazoles. Mechanistic studies support the intermediacy of allylsulfonium salts that undergo facile thio-Claisen rearrangement onto the heterocyclic ring, giving products of coupling. The strategy has been adapted to allow regiospecific propargylation of the heterocyclic substrates.
Fedorova,A.V. et al., Doklady Chemistry, 1962, vol. 145, p. 698 - 701
作者:Fedorova,A.V. et al.
DOI:——
日期:——
Palladium-Catalyzed Oxidative Silylation of Simple Olefins To Give Allylsilanes Using Hexamethyldisilane and Molecular Oxygen as the Sole Oxidant
A Pd-catalyzed oxidative silylation of simple olefins with hexamethyldisilane to give allylsilanes has been achieved usingmolecularoxygen as the sole oxidant. The reaction provides a useful protocol to access synthetically useful allylsilanes from easily accessible simple olefins and hexamethyldisilane without using any oxidants other than O2.