Diastereodivergent Synthesis of Pentacyclic Spiroindolines via a Magnesium(II)-Catalyzed Cascade Reaction of <i>N,N</i>′-Cyclic Azomethine Imines with Indolyl-Substituted Isocyanides
Jianfeng Zheng, Lin Yang, Xin Dai, Lvli Chen, Luhao Tang, Yuqiao Zhou, Wei‐Dong Z. Li
Abstract
Magnesium(II)-catalyzed cascade reactions of N,N ′-cyclic azomethine imines with indolyl-substituted isocyanides are reported herein. The method exhibited a high functional group tolerance and broad substrate scope. A series of anti -pentacyclic spiroindolines containing N,N ′-fused heterocycle skeletons were obtained in up to 82% yield with 8.5:1 dr under mild reaction conditions. Intriguingly, a sequential HOAc-mediated protonation results in a diastereoenriched epimerization, which gives rise to the syn -pentacyclic spiroindolines as the sole isomers.
Topics & Concepts
ChemistryCatalysisMagnesiumEpimerProtonationYield (engineering)Substrate (aquarium)Reaction conditionsStereochemistryCascade reactionMedicinal chemistryCombinatorial chemistryOrganic chemistryGeologyOceanographyIonMetallurgyMaterials scienceSynthesis of Indole DerivativesAsymmetric Synthesis and CatalysisMulticomponent Synthesis of Heterocycles