Unsymmetrical Biaryls by Palladium-Catalyzed Coupling of Aryl Halides with Internal Reduction
作者:Gedu Satyanarayana、Martin E. Maier
DOI:10.1002/ejoc.200800724
日期:2008.11
intermediate eventually leads to mixed biaryls by reductive elimination and β-hydride elimination. The best yields were obtained with 2 equiv. of aryl halide. The required substrates were prepared from bromoiodobenzenes by a sequence consisting of a Heck reaction with allyl alcohol, enamine formation, Michael addition to ethyl acrylate, and heterocycle formation with benzylamine.(© Wiley-VCH Verlag GmbH & Co.
含有(1,4,5,6-四氢-6-氧代吡啶-3-基)甲基取代基的芳基溴化物可以与芳基卤化物偶联,产生不饱和的联芳基。在此过程中,环状烯酰胺被氧化为 2(1H)-吡啶酮。该反应通过环状烯酰胺的烯丙基 C-H 键活化产生的六元钯环进行,导致六元钯环。随后与芳基-Pd-X 中间体的金属转移反应最终通过还原消除和 β-氢化物消除产生混合联芳基化合物。最好的产量是用 2 当量获得的。芳基卤化物。所需的底物由溴碘苯通过与烯丙醇的 Heck 反应、烯胺形成、迈克尔加成到丙烯酸乙酯和与苄胺形成杂环组成的顺序制备。