Asymmetric Synthesis of Spiro-3,3′-cyclopropyl Oxindoles via Vinylogous Michael Initiated Ring Closure Reaction
Abhijit Manna, Harshit Joshi, Vinod K. Singh
Abstract
A novel organocatalytic cascade approach for the synthesis of spiro-cyclopropyl oxindole derivatives has been developed. The methodology is based on asymmetric vinylogous Michael addition of 4-nitroisoxazole derivatives to N-Boc isatylidene malonates followed by intramolecular alkylation. Its remarkable stereocontrol, wide substrate scope, and scalability highlight this new developed strategy. Moreover, this work represents the first example of vinylogous Michael initiated ring closure (MIRC) reaction for the synthesis of chiral 3,3′-cyclopropyl oxindole.
Topics & Concepts
Closure (psychology)Ring (chemistry)Michael reactionChemistryStereochemistryCatalysisOrganic chemistryPolitical scienceLawCyclopropane Reaction MechanismsAsymmetric Synthesis and CatalysisSynthetic Organic Chemistry Methods