Herein, we report a bromide-mediated, C2-selective, and oxygenative alkylation of pyridinium salts using alkenes and O2 for the synthesis of important β-2-pyridyl ketones. Notably, a quaternary carbon center was successfully installed at the C2-position of pyridine and the resulting C2-substituents were highly functionalized. The intermediary cycloadduct was isolated and further transformed into the
在此,我们报告了使用烯烃和 O 2对
吡啶盐进行
溴化物介导、C2 选择性和含氧烷基化,以合成重要的β -2-
吡啶基酮。值得注意的是,季碳中心成功地安装在
吡啶的 C2 位,由此产生的 C2 取代基被高度官能化。中间环加合物被分离并进一步转化为所需产物,这表明该三组分反应经历了包括脱芳环加成和再芳环开环氧化在内的反应级联。最后,讨论了
溴化物介导的机制,并提出原位生成活性Br( I ) 物种并通过卤键辅助电子转移促进再芳香化开环氧化。