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Frontier molecular orbital effects control the hole-catalyzed racemization of atropisomeric biaryls.

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.

SUBMITTER: Tan JSJ

PROVIDER: S-EPMC6399675 | biostudies-literature | 2019 Feb

REPOSITORIES: biostudies-literature

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Frontier molecular orbital effects control the hole-catalyzed racemization of atropisomeric biaryls.

Tan Jacqueline S J JSJ Paton Robert S RS

Chemical science 20181218 8

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 studi ...[more]

PMID: 30931095

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