Related Experiment Video
Updated: Feb 3, 2026

Free Radicals in Chemical Biology: from Chemical Behavior to Biomarker Development
Published on: April 15, 2013
Asymmetric Aerobic Intramolecular Dearomative ortho Coupling of Tethered Phenols by Chromium-Salen Complex/Nitroxyl
Shota Nagasawa1, Nao Yokota1, Shogo Fujiki1
1Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan.
Abstract:
Herein, we report the catalytic asymmetric intramolecular dearomative coupling of tethered phenols in ortho-para fashion under aerobic conditions. Cooperative catalysis with a chromium-salen complex/nitroxyl radical enabled the desired transformation to proceed at ambient temperature under oxygen atmosphere. A range of tethered phenols were efficiently converted into spirocyclic 2,4-dienones in moderate to good yields and enantioselectivities (up to 68% enantiomeric excess (ee)).
Related Concept Videos
Radical Reactivity: Intramolecular vs Intermolecular
Catalysis
Intermolecular vs Intramolecular Forces
Intramolecular Aldol Reaction
Rotation of Asymmetric Top
The relationship between the angular momentum of any rigid body and its angular velocity, both of which are vectors, involves the moment of inertia. The moment of inertia is a scalar quantity only for spherically symmetric...
Directing Effect of Substituents: ortho–para-Directing Groups

