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Updated: Jan 27, 2026

Three-Dimensional Reconstruction of Orbital Fractures
Published on: May 16, 2025
Frontier molecular orbital effects control the hole-catalyzed racemization of atropisomeric biaryls
Jacqueline S J Tan1, Robert S Paton2
1Chemistry Research Laboratory , University of Oxford , 12 Mansfield Road , Oxford , OX1 3TA , UK.
Abstract:
Atropisomeric biaryl systems are privileged architectures used in asymmetric synthesis and pharmaceutical structures. We report that by simply removing a single-electron, the resistance of biaryls towards racemization is reduced dramatically. Even though the steric properties are unaltered, biaryl oxidation changes atropisomerization into a two step mechanism with considerably smaller activation barriers than closed-shell biaryls. The effect is general for a series of biaryls and helicenes studied and results from the dependence of frontier molecular orbital energies on biaryl conformation.
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