School of Pharmaceutic Sciences, Soochow University, Suzhou, 215123, China.
Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai, 201203, China.
Chem Commun (Camb). 2022 Jul 26;58(60):8340-8343. doi: 10.1039/d2cc02245a.
An unexpected iodine()-mediated C(sp)-C(sp) bond cleavage of 3-(methylamino)-2-(2-substitutedbenzoyl)acrylates for efficient synthesis of privileged scaffold 4-quinolones was described. Notably, a wide range of alkyl groups ( methyl, -butyl or alkyl chain) can be conveniently cleaved in this system. The detailed mechanism studies revealed that the transformation proceeded through cascade ipso-cyclization and 1,2-carbonyl migration, the smaller bond energy determined C-C bond cleavage rather than C-H bond cleavage, an enamine radical intermediate.
本文描述了一种意想不到的碘介导的 3-(甲基氨基)-2-(2-取代苯甲酰基)丙烯酸酯的 C(sp)-C(sp)键断裂反应，可用于高效合成重要的 4-喹诺酮骨架。值得注意的是，在此体系中可以方便地断裂各种烷基（甲基、-丁基或烷基链）。详细的机理研究表明，该转化通过级联的 ipso-环化和 1,2-羰基迁移进行，较小的键能决定了 C-C 键的断裂而不是 C-H 键的断裂，生成烯胺自由基中间体。
