Oxidative [3+3] cycloadditions offer an efficient route for six‐membered‐ring formation. This approach has been realized based on an electrochemical oxidative coupling of indoles/enamines with active methylene compounds followed by tandem 6π‐electrocyclization leading to the synthesis of dihydropyrano[4,3‐b ]indoles and 2,3‐dihydrofurans. The radical–radical cross‐coupling of the radical species generated by anodic oxidation combined with the cathodic generation of the base from O₂ allows for mild reaction conditions for the synthesis of structurally complex heterocycles.

中文翻译：

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基于双氧化[3 + 3]环加成反应的二氢吡喃并[4,3-b]吲哚的电合成。

氧化性[3 + 3]环加成反应为六元环形成提供了一条有效途径。该方法是基于吲哚/烯胺与活性亚甲基化合物的电化学氧化偶联，然后串联6π-电环化反应生成二氢吡喃并[4,3- b ]吲哚和2,3-二氢呋喃而实现的。阳极氧化产生的自由基与自由基从O ₂产生的自由基之间的自由基交叉偶联为合成结构复杂的杂环提供了温和的反应条件。