Institute for Advanced Study, Chengdu University, Chengdu 610106, China.
Key Laboratory of Biocatalysis & Chiral Drug Synthesis of Guizhou Province, Generic Drug Research Center of Guizhou Province, School of Pharmacy, Zunyi Medical University, Zunyi 563006, China.
Org Lett. 2020 Sep 18;22(18):7088-7093. doi: 10.1021/acs.orglett.0c02350. Epub 2020 Aug 28.
The first catalytic enantioselective dearomatization/rearomatization of 2-nitroindoles triggered by the Michael addition of 3-monosubstituted oxindoles was established. A wide range of 3-indolyl-3'-alkyloxindoles (up to 99% yield, 97% ee) and 3-indolyl-3'-aryloxindoles (up to 95% yield, 99% ee) were obtained by using an organocatalyst. This method provides an unprecedented strategy to access structurally diverse 3,3'-disubstituted oxindoles bearing a sterically congested triaryl-containing all-carbon quaternary stereocenter. The utility of this approach was verified by the formal synthesis of cyclotryptamine alkaloids.
首次建立了 3-单取代吲哚啉与 2-硝基吲哚的迈克尔加成引发的 2-硝基吲哚的首例催化对映选择性去芳构化/再芳构化反应。使用有机催化剂，可以获得广泛的 3-吲哚基-3'-烷氧基吲哚啉（高达 99%的收率，97%ee）和 3-吲哚基-3'-芳氧基吲哚啉（高达 95%的收率，99%ee）。该方法提供了一种前所未有的策略，可获得具有空间位阻的三芳基含全碳季碳立体中心的结构多样的 3,3'-二取代氧吲哚啉。该方法的实用性通过环色胺生物碱的形式合成得到了验证。
