Asymmetric α-spirocyclopropanation of oxindoles and benzofuranones via dynamic kinetic resolution

作者：Yang Hu, Jie Yuan, Zheyao Li, Lin Zhao, Jianhong Zhao, Xinhong Yu · 发表于：Communications Chemistry · 年份：2022 · DOI：10.1038/s42004-022-00695-3 · 被引用次数：6 · 研究领域：Cyclopropane Reaction Mechanisms、Asymmetric Synthesis and Catalysis、Synthetic Organic Chemistry Methods

Chiral benzo five-membered heterocyclic spirocyclopropanes are an important class of parent core structures with pharmacological activity. A novel organocatalytic one-pot cascade ether oxidation iminium-ion activation strategy for the asymmetric spirocyclopropylation of benzofuran-2-ones and indolin-2-ones from allyl tert-butyl ethers/ pent-2,4-dienyl ethyl ethers with excellent enantioselectivity (ee% up to > 99) and diastereoselectivity(dr.% up to 91:9) has been developed. This process involves the successful dynamic kinetic resolution of racemic 3-bromobenzofuran-2-ones or 3-bromoindolin-2-ones. Its synthetic application will provide a new aminocatalytic cascade tool for the efficient synthesis of complex molecules.