Zhou Wei, Li Zi-Qiong, Cheng Chaozhihui, Lu Lin, Yang Ruchun, Song Xian-Rong, Luo Mu-Jia, Xiao Qiang
Key Laboratory of Organic Chemistry of Jiangxi Province, Jiangxi Science & Technology Normal University, Nanchang, 330013, China.
Org Lett. 2023 Dec 29;25(51):9158-9163. doi: 10.1021/acs.orglett.3c03678. Epub 2023 Dec 15.
Herein, a novel electrochemical arene radical cation promoted dearomative spirocyclization of biaryl ynones with alcohols is described, providing a conceptually novel transformation mode for producing diverse alkoxylated spiro[5,5]trienones. The catalyst- and chemical-oxidant-free spirocyclization protocol features broad substrate scope and high functional group tolerance. Mechanistic studies reveal that the generation of arene radical cation via anodic single-electron oxidation is crucial, with sequential 6-- cyclization, dissociation of hemiketal, anodic oxidation, and nucleophilic attack of alcohols.
在此，描述了一种新型的电化学芳烃自由基阳离子促进的联芳基炔酮与醇的去芳构化螺环化反应，为制备多种烷氧基化螺[5,5]三烯酮提供了一种概念上全新的转化模式。该无催化剂和化学氧化剂的螺环化反应方案具有广泛的底物范围和高官能团耐受性。机理研究表明，通过阳极单电子氧化生成芳烃自由基阳离子至关重要，随后依次进行6-环化、半缩酮解离、阳极氧化以及醇的亲核进攻。
