Palladium-Catalyzed Allylic Cross-Coupling Reactions of Primary and Secondary Homoallylic Electrophiles
作者:Benjamin J. Stokes、Susanne M. Opra、Matthew S. Sigman
DOI:10.1021/ja305403s
日期:2012.7.18
cross-coupling of homoallylic tosylate substrates using boronic acids and pinacol esters is reported. The reaction uses 2-(4,5-dihydro-2-oxazolyl)quinoline (quinox) as a ligand and is performed at ambient temperature. The scope of the reaction is broad in terms of both the boronate transmetalating reagent and the substrate and includes secondary tosylates. Mechanistic studies support an alkene-mediated
Copper-catalyzed oxidative alkenylation of C(sp<sup>3</sup>)–H bonds via benzyl or alkyl radical addition to β-nitrostyrenes
作者:Shengrong Guo、Yanqin Yuan、Jiannan Xiang
DOI:10.1039/c4nj02416h
日期:——
A new method for the preparation of (E)-β-alkylstyrene derivatives has been developed via the addition of a benzyl or alkyl radical to β-nitrostyrenes using di-tert-butyl peroxide (DTBP) as the oxidant in the presence of Cu powder catalyst. The C–H bonds in various toluene derivatives, ethers, alkanes and alcohols were successfully converted into C–C bonds to yield the corresponding (E)-β-alkylstyrene
We herein report a transition-metal-free cross-coupling between secondaryalkylhalides/mesylates and aryl/alkenylboronic acid, providing expedited access to a series of nonchiral/chiral coupling products in moderate to good yields. Stereospecific SN2-type coupling is developed for the first time with alkenylboronic acids as pure nucleophiles, offering an attractive alternative to the stereospecific