Site-selective cross-coupling of dihaloarenes constitutes a useful method for synthesis of multi-substituted arenes. In this paper, we report the site-selective cross-coupling of dichlorinated benzo-fused nitrogen-heterocycles having two chloro groups on the benzene ring. These dichlorinated heterocycles reacted with Grignard reagents in the presence of PdCl2(PCy3)2 at the positions ortho to the nitrogen-based substituents with high selectivities. A mechanism in which interaction between Lewis acidic Mg and Cl of the ortho position facilitates C–Cl bond cleavage is proposed.
二卤
芳烃的位点选择性交叉偶联是一种合成多取代
芳烃的有效方法。在本文中,我们报告了氮杂环苯并融合的二
氯化物的位点选择性交叉偶联,这些化合物在苯环上有两个
氯基团。这些二
氯化异环化合物在PdCl2(PCy3)2的存在下,与
格氏试剂发生反应,反应位置选择性高,主要发生在与氮基取代基邻位。我们提出了一种机制,其中
路易斯酸性
镁与邻位
氯的相互作用促进了C–Cl键的断裂。