Chen Ziren, Xue Fei, Feng Wanting, Zhang Zuozhi, Wang Bin, Zhang Yonghong, Jin Weiwei, Xia Yu, Liu Chenjiang
Urumqi Key Laboratory of Green Catalysis and Synthesis Technology, Key Laboratory of Oil and Gas Fine Chemicals, Ministry of Education & Xinjiang Uygur Autonomous Region, State Key Laboratory of Chemistry and Utilization of Carbon Based Energy Resources, College of Chemistry, Xinjiang University, Urumqi 830017, P. R. China.
Key Laboratory of Specialty Agri-Product Quality and Hazard Controlling Technology of Zhejiang Province, College of Life Sciences, China Jiliang University, Hangzhou 310018, P. R. China.
Org Lett. 2024 Sep 13;26(36):7614-7619. doi: 10.1021/acs.orglett.4c02723. Epub 2024 Sep 5.
A green and efficient protocol for the preparation of benzo[]carbazoles via visible-light-promoted and electron donor-acceptor (EDA) complex-driven intermolecular cyclization of 2-arylindoles with -α-bromocinnamaldehydes in the absence of external photocatalysts, transition metals, and oxidants was reported. This new approach demonstrates an intermolecular cyclization model using indole derivatives as electron donors under visible light. Mechanistic investigations have showed that 2-arylindoles with -α-bromocinnamaldehydes form EDA complexes, which undergo sequential single-electron transfer, radical coupling, 6π-electrocyclization, and dehydroaromatization to generate benzo[]carbazoles under visible light irradiation. The current photochemical method features readily accessible starting materials, mild conditions, simple operation, and a broad substrate scope.
报道了一种绿色高效的方法，用于在无外部光催化剂、过渡金属和氧化剂的情况下，通过可见光促进和电子供体-受体（EDA）络合物驱动的2-芳基吲哚与α-溴肉桂醛的分子内环化反应制备苯并[]咔唑。这种新方法展示了一种在可见光下以吲哚衍生物作为电子供体的分子内环化模型。机理研究表明，2-芳基吲哚与α-溴肉桂醛形成EDA络合物，该络合物在可见光照射下依次进行单电子转移、自由基偶联、6π-电环化和脱氢芳构化反应，生成苯并[]咔唑。目前的光化学方法具有起始原料易于获得、条件温和、操作简单和底物范围广的特点。
