State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences , Kunming 650201, Yunnan, China.
J Am Chem Soc. 2014 Dec 31;136(52):17962-5. doi: 10.1021/ja5121343. Epub 2014 Dec 17.
A facile and straightforward method was developed to construct the fused tetracyclic 3-spirooxindole skeleton, which exists widely in natural products. The formation of the tetracyclic 3-spirooxindole structure was achieved through a transition-metal-free intramolecular cross-dehydrogenative coupling of pyridinium, which were formed in situ by the condensation of 3-(2-bromoethyl)indolin-2-one derivatives with 3-substituted pyridines. As examples of the application of this new methodology, two potentially medicinal natural products, (±)-corynoxine and (±)-corynoxine B, were efficiently synthesized in five scalable steps.
本文发展了一种简便的方法来构建广泛存在于天然产物中的融合四环 3-螺氧化吲哚骨架。该四环 3-螺氧化吲哚结构的形成是通过无过渡金属的分子内交叉脱氢偶联来实现的，其中吡啶鎓是由 3-(2-溴乙基)吲哚啉-2-酮衍生物与 3-取代吡啶缩合原位形成的。作为该新方法的应用实例，两种潜在的药用天然产物(±)-可柯诺辛和(±)-可柯诺辛 B 可以通过 5 步放大反应高效合成。
