Zhou Nengneng, Zhao Fangli, Wang Lei, Gao Xiang, Zhao Xiaowei, Zhang Man
Key Laboratory of Functionalized Molecular Solids, Ministry of Education, Anhui Key Laboratory of Molecule-Based Materials, College of Chemistry and Materials Science, Anhui Normal University, Wuhu, Anhui 241000, China.
J Org Chem. 2024 Feb 16;89(4):2238-2246. doi: 10.1021/acs.joc.3c02184. Epub 2024 Jan 31.
Visible-light-induced regioselective cascade radical cyclization of α-bromocarbonyls for the synthesis of benzazepine derivatives is described. In the presence of -Ir(ppy) (2.0 mol %) as a photocatalyst, 2,6-lutidine as a base, and dichloromethane as a solvent, the reactions proceed smoothly to afford seven-membered rings in good yields. This protocol features a broad substrate scope, excellent functional group tolerance, and mild reaction conditions. Preliminary mechanistic studies reveal that the generation of the α-carbon radical is more prone to react with the 1,1-diphenylethylene tethered acrylamide to generate the stable seven-membered heterocycle.
描述了用于合成苯并氮杂䓬衍生物的可见光诱导的α-溴代羰基化合物的区域选择性级联自由基环化反应。在作为光催化剂的-Ir(ppy)（2.0 mol%）、作为碱的2,6-二甲基吡啶和作为溶剂的二氯甲烷存在下，反应顺利进行，以良好的产率得到七元环。该方法具有底物范围广、官能团耐受性好和反应条件温和的特点。初步机理研究表明，α-碳自由基的生成更倾向于与连接有丙烯酰胺的1,1-二苯乙烯反应，生成稳定的七元杂环。
