Organocatalytic Asymmetric Synthesis of Aza-Spirooxindoles via Michael/Friedel–Crafts Cascade Reaction of 1,3-Nitroenynes and 3-Pyrrolyloxindoles
Qijian Ni, Xuyang Wang, Da Zeng, Qianling Wu, Xiaoxiao Song
Abstract
An asymmetric [3+3] cyclization of nitroenynes and 3-pyrrolyloxindoles has been realized with a chiral bifunctional squaramide catalyst. This Michael/Friedel-Crafts cascade strategy provides a facile and efficient access to enantioenriched polycyclic aza-spirooxindoles with 32-95% isolated yields and excellent stereocontrol under mild reaction conditions.
Topics & Concepts
SquaramideChemistryBifunctionalFriedel–Crafts reactionCascadeMichael reactionCascade reactionCatalysisCombinatorial chemistryOrganocatalysisOrganic chemistryEnantioselective synthesisChromatographyAsymmetric Synthesis and CatalysisSynthesis and Catalytic ReactionsAsymmetric Hydrogenation and Catalysis