Synthesis of Substituted Monohalobenzenes via Ortho-Selective Cross-Coupling of Dihalobenzenes with Electron-Donating Ortho-Directing Groups
作者:Kei Manabe、Shunpei Ishikawa
DOI:10.1055/s-2008-1067270
日期:2008.10
Dihalobenzenes that possess directing groups such as OH, CH 2 OH, NH 2 , NHAc, or NHBoc were subjected to ortho-selective cross-coupling with Grignard reagents in the presence of palladium-based catalysts to give the corresponding substituted monohalobenzenes. For the dibromo- and dichlorophenols and anilines, hydroxylated terphenylphosphines 1 and 2 were found to be effective ligands for palladium
<i>Ortho</i>-Selective Cross-Coupling of Fluorobenzenes with Grignard Reagents: Acceleration by Electron-Donating<i>Ortho</i>-Directing Groups
作者:Kei Manabe、Shunpei Ishikawa
DOI:10.1055/s-2008-1067182
日期:2008.8
Fluorobenzenes with directing groups such as hydroxy, hydroxymethyl, and ammo underwent ortho-selective cross-coupling with Grignardreagents in the presence of palladium-based catalysts, with dichlorobis(tricyclohexylphosphine)palladium [PdCl 2 (PCy 3 ) 2 ] found to be the optimum catalyst. Fluoro and chloro groups at positions other than ortho to the directing groups survived under the reaction conditions
Negishi coupling strategy of a repetitive two-step method for oligoarene synthesis
作者:Haruka Shimizu、Kei Manabe
DOI:10.1016/j.tetlet.2006.06.048
日期:2006.8
repetitive two-step method for oligoarene synthesis, based on Negishi cross-coupling of zinciophenoxides or zinciopyridinoxides with aryl triflates and subsequent triflation of the hydroxy group, was developed. Reaction conditions were optimized for the preparation of the arylzinc compounds and the palladium-catalyzedcross-coupling step.