Enantioselectivity-Switchable Organocatalytic [4 + 2]-Annulation to Access the Spirooxindole–Norcamphor Scaffold
Jing Wang, Xian-Zhou Zheng, Jun‐An Xiao, Kai Chen, Hao‐Yue Xiang, Xiaoqing Chen, Hua Yang
Abstract
An organocatalyzed enantiodivergent synthesis of a multifunctionalized spirooxindole–norcamphor scaffold via a [4 + 2]-annulation between cyclicα, β-unsaturated ketone and methylene indolinones has been established. The presence of CaCl2 in DMF could reverse the enantioselectivity to facilely deliver the enantiomers of the corresponding spirooxindoles. Both enantiomers of the corresponding spirooxindoles were obtained in excellent yield and diastereo-/enantioselectivity by employing one single prolinosulfonamide catalyst.
Topics & Concepts
ChemistryAnnulationEnantiomerCatalysisYield (engineering)MethyleneCombinatorial chemistryScaffoldStereochemistryOrganic chemistryComputer scienceMaterials scienceMetallurgyDatabaseAsymmetric Synthesis and CatalysisSynthetic Organic Chemistry MethodsOxidative Organic Chemistry Reactions