Rapid Access to Spirocyclic Oxindole Alkaloids: Application of the Asymmetric Palladium-Catalyzed [3 + 2] Trimethylenemethane Cycloaddition
作者:Barry M. Trost、Dustin A. Bringley、Ting Zhang、Nicolai Cramer
DOI:10.1021/ja409013m
日期:2013.11.6
2]diazaoctane fused to a spirooxindole. Herein, we report the synthesis of two members of this family. The synthesis of marcfortine B utilizes a carboxylative TMM cycloaddition to establish the spirocyclic core, followed by an intramolecular Michael addition and oxidative radical cyclization to access the strained bicyclic ring system. In addition, the first asymmetric synthesis of (−)-marcfortine C is described
marcfortines 是复杂的次生代谢物,显示出有效的驱虫活性,其特征是存在与螺吲哚融合的双环 [2.2.2] 二氮杂辛烷。在此,我们报告了该家族的两个成员的合成。marcfortine B 的合成利用羧基 TMM 环加成来建立螺环核心,然后是分子内迈克尔加成和氧化自由基环化以进入应变双环系统。此外,还描述了 (-)-marcfortine C 的首次不对称合成。关键步骤涉及氰基取代的 TMM 环加成,其以几乎定量的收率进行,具有高非对映选择性和对映选择性。所得手性中心用于建立天然产物中所有剩余的立体中心。