The development of efficient cascade reactions is highly important and appealing because of their desirable step-economy and convenience in constructing multiple chemical bonds and complex molecules in one shot. Herein, we report a rare four-step tandem reaction between acrylamides and 4-hydroxy-2-alkynoates to prepare novel furo[3,4-c]pyridine-1,4-diones which are difficult to synthesize by traditional methods. This unique domino reaction includes C–H activation, Lossen rearrangement, annulation, and lactonization. Additionally, this protocol features good functional group tolerance, obtainment of products by simple filtration, room temperature, and air compatibility. DFT calculations were conducted to shed some light on the reaction mechanism.

中文翻译：

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通过铑催化获得呋喃[3,4-c]吡啶-1,4-二酮的不寻常的四步级联反应

高效的级联反应的发展非常重要且有吸引力，因为它们具有理想的步骤经济性和一次性构建多个化学键和复杂分子的便利性。在此，我们报道了丙烯酰胺和4-羟基-2-炔酸酯之间罕见的四步串联反应，以制备传统方法难以合成的新型呋喃[3,4- c ]吡啶-1,4-二酮。这种独特的多米诺骨牌反应包括 C-H 激活、Lossen 重排、环化和内酯化。此外，该方案还具有良好的官能团耐受性、通过简单过滤即可获得产品、室温和空气相容性。进行 DFT 计算以阐明反应机理。