Brønsted Acid Catalyzed Enantioselective Assembly of Spirochroman-3,3-oxindoles
Alavala Gopi Krishna Reddy, Pedireddi Niharika, Su Zhou, Shi‐Kun Jia, Taoda Shi, Xinfang Xu, Yu Qian, Wenhao Hu
Abstract
-hydroxymethyl chalcones has been established by a cooperative dirhodium complex and chiral phosphonic acid catalysis under mild conditions. This reaction is the first example of catalytic asymmetric intramolecular Michael-type trapping of oxonium ylide enabled by phosphoric acid through a dual H-bonding activation model, which provides an efficient access to the chiral spirochroman-3,3-oxindoles, with vicinal quaternary and tertiary stereocenters, in good to excellent yields and enantioselectivities.
Topics & Concepts
StereocenterEnantioselective synthesisChemistryOxonium ionCatalysisIntramolecular forceYlidePhosphoric acidBrønsted–Lowry acid–base theoryHydroxymethylVicinalOrganocatalysisCombinatorial chemistryStereochemistryMedicinal chemistryOrganic chemistryIonCyclopropane Reaction MechanismsSynthetic Organic Chemistry MethodsAsymmetric Synthesis and Catalysis