Palladium-Catalyzed Buchwald–Hartwig Coupling of Deactivated Aminothiophenes with Substituted Halopyridines
作者:Agathe Begouin、Stéphanie Hesse、Maria-João R. P. Queiroz、Gilbert Kirsch
DOI:10.1002/ejoc.200600951
日期:2007.4
The palladium-catalyzed Buchwald–Hartwig coupling of several deactivated aminothiophenecarboxylates with differently substituted halopyridines has been performed for the first time by using Pd(OAc)2, Xantphos as the ligand, and Cs2CO3 as the base. When 2,6-dihalopyridines were used, the proportion of diaminated product increases with the reactivity of the halopyridines (iodo > bromo > chloro). A bromo
通过使用 Pd(OAc)2、Xantphos 作为配体和 Cs2CO3 作为碱,钯催化的几种失活氨基噻吩羧酸盐与不同取代的卤代吡啶的 Buchwald-Hartwig 偶联首次进行。当使用 2,6-二卤代吡啶时,二胺化产物的比例随着卤代吡啶的反应性而增加(碘 > 溴 > 氯)。通过 Buchwald-Hartwig 偶联获得的溴单胺化吡啶衍生物进一步用于带有吸电子或给电子基团的芳基硼酸的 Suzuki 偶联。这些后一种化合物非常有趣,因为它们具有二杂芳基胺和杂芳基-芳基骨架,包括吡啶和噻吩部分。(© Wiley-VCH Verlag GmbH & Co. KGaA,69451 Weinheim,德国,2007)