Brønsted Acid Catalyzed Enantioselective Assembly of Spirochroman-3,3-oxindoles

Org Lett. 2020 Apr 17;22(8):2925-2930. doi: 10.1021/acs.orglett.0c00587. Epub 2020 Apr 1.

Abstract

An enantioselective cyclization of diazoindolinones with o-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.

Publication types

  • Research Support, Non-U.S. Gov't