Copper-Catalyzed Umpolung of <i>N</i>-2,2,2-Trifluoroethylisatin Ketimines for the Enantioselective 1,3-Dipolar Cycloaddition with Benzo[<i>b</i>]thiophene Sulfones
Wei‐Cheng Yuan, Lei Yang, Jian‐Qiang Zhao, Hongyan Du, Zhen‐Hua Wang, Yong You, Yanping Zhang, Jiabin Liu, Wenjing Zhang, Ming‐Qiang Zhou
Abstract
A copper-catalyzed umpolung of N-2,2,2-trifluoroethylisatin ketimines for the enantioselective 1,3-dipolar cycloaddition with benzo[b]thiophene sulfones was developed. Using a catalyst system consisting of an (S,Sp)-tBu-Phosferrox ligand, Cu(OTf)2, and Cs2CO3, a range of pentacyclic spirooxindoles containing pyrrolidine and benzo[b]sulfolane subunits were obtained in high efficiency with excellent regio-, diastereo-, and enantioselectivites under mild conditions. The practicality and versatility of the reaction were also demonstrated.
Topics & Concepts
UmpolungChemistryEnantioselective synthesisThiopheneCycloadditionCatalysisPyrrolidineMedicinal chemistryLigand (biochemistry)StereochemistryOrganic chemistryCombinatorial chemistryReceptorBiochemistryNucleophileSynthesis and Catalytic ReactionsSulfur-Based Synthesis TechniquesCyclopropane Reaction Mechanisms