A facile preparation of 3-hydroxylisoquinolin-1, 4-diones and piperidine-2,5-dione from alkyne-tethered amide is reported under cerium photocatalysis and O₂ balloon. The reaction works well with a broad reaction scope and reaction efficiency. Mechanism studies indicate that 3-hydroxylpyrrolidin-2-one-containing α-ketol radical species serves as a possible key intermediate, and the final product is attributed to a formal N-centered radical initiated [2 + 2] cyclization and α-ketol rearrangement. Interestingly, divergence towards CN bond migration and CC bond migration is reached in this radical α-ketol rearrangement.

中文翻译：

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炔烃系链的N-烷氧基酰胺与O ₂在铈的光催化下制备3-羟基异喹啉-1,4-二酮和哌啶-2,5-二酮

据报道，在铈的光催化作用和O ₂气球作用下，由炔烃连接的酰胺可轻松制备3-羟基异喹啉-1、4-二酮和哌啶-2,5-二酮。反应良好，反应范围广，反应效率高。机理研究表明，含3-羟基吡咯烷酮-2-一的α-酮醇自由基可能是关键中间体，而最终产物归因于正式的以N为中心的自由基引发的[2 + 2]环化和α-酮醇重排。有趣的是，在这种自由基α-酮醇重排中，朝着C N键迁移和C C键迁移发散。