Maejima Saki, Yamaguchi Eiji, Itoh Akichika
Gifu Pharmaceutical University , 1-25-4, Daigaku-nishi , Gifu 501-1196 , Japan.
J Org Chem. 2019 Aug 2;84(15):9519-9531. doi: 10.1021/acs.joc.9b01081. Epub 2019 Jun 7.
In this study, intermolecular spirolactonization via an iodine/visible-light-mediated C-C/C-O bond formation reaction was developed. The developed reaction proceeded to form quaternary carbon centers via carboesterification between cyclic β-keto esters and olefins, affording spirolactone derivatives in a single step. In addition, the mechanistic investigation revealed that the generation of iodine radicals from molecular iodine driven by visible-light irradiation is a crucial step. The developed reaction proceeded under milder conditions than previously reported procedures as iodine played a role of a conventional transition-metal catalyst, realizing an environmentally friendly, novel molecular transformation.
在本研究中，通过碘/可见光介导的C-C/C-O键形成反应开发了分子间螺内酯化反应。所开发的反应通过环状β-酮酯与烯烃之间的碳酯化反应形成季碳中心，一步得到螺内酯衍生物。此外，机理研究表明，可见光照射驱动分子碘生成碘自由基是关键步骤。由于碘起到了传统过渡金属催化剂的作用，所开发的反应在比先前报道的方法更温和的条件下进行，实现了环境友好的新型分子转化。
