Li Min, Tan Qiujian, Lyu Xiang, Guo Xiaoyu, Wang Hui, Hu Zhongyan, Xu Xianxiu
College of Chemistry, Chemical Engineering and Materials Science, Shandong Normal University, Jinan 250014, China.
Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon 34141, South Korea.
Org Lett. 2024 Jul 12;26(27):5799-5804. doi: 10.1021/acs.orglett.4c01977. Epub 2024 Jul 2.
Herein, we disclose a photoinduced radical cascade cyclization of alkynes with sulfinates via a novel EDA complex for the synthesis of various 3-sulfonylindoles and vinyl sulfone oxindoles, which are crucial motifs in medicinal and biological chemistry. The reaction proceeds under mild, photocatalyst- and transition-metal-free conditions, featuring operational simplicity, broad substrate scope, and easy scalability. Mechanistic studies reveal that the reaction is initiated with a photoinduced intermolecular charge transfer from sulfinates to -sulfonamides, generating a sulfonyl radical followed by an -centered radical, thus enabling the cascade cyclization process.
在此，我们报道了一种通过新型电子给体-受体（EDA）络合物实现的炔烃与亚磺酸盐的光诱导自由基级联环化反应，用于合成各种3-磺酰基吲哚和乙烯基砜氧化吲哚，这些都是药物化学和生物化学中的关键结构单元。该反应在温和、无光催化剂和无过渡金属的条件下进行，具有操作简便、底物范围广和易于放大等特点。机理研究表明，该反应由光诱导的分子间电荷从亚磺酸盐转移到磺酰胺开始，生成磺酰基自由基，随后是碳中心自由基，从而实现级联环化过程。
