The copper-catalyzed [4 + 2] annulation of α,β-unsaturated ketoxime acetates with 1,3-dicarbonyl compounds for the synthesis of three classes of structurally diverse pyridines has been developed. This method employs 1,3-dicarbonyl compounds as C2 synthons and enables the synthesis of multifunctionalized pyridines with diverse electron-withdrawing groups in moderate to good yields. The mechanistic investigation suggests that the reactions proceed through an ionic pathway.

中文翻译：

---

铜催化的α，β-不饱和酮肟乙酸酯对结构多样的吡啶的NO裂解。

已经开发了铜催化的α，β-不饱和酮肟肟乙酸盐与[1,3-二羰基化合物的铜催化[4 + 2]环合反应，用于合成三类结构多样的吡啶。该方法采用1,3-二羰基化合物作为C2合成子，并能够以中等至良好的产率合成具有不同吸电子基团的多官能吡啶。机理研究表明反应是通过离子途径进行的。