Charge-transfer effect on chiral phosphoric acid catalyzed asymmetric Baeyer-Villiger oxidation of 3-substituted cyclobutanones using 30% aqueous H₂O₂ as the oxidant

The intermolecular charge-transfer effect has been employed for the first time as a modulating approach to affect the enantioselectivity in asymmetric catalysis by taking the chiral phosphoric acid catalyzed asymmetric Baeyer-Villiger oxidation of 3-aryl cyclobutanones as the reaction prototype. It was found that the electron acceptor additives were able to effectively tune the enantioselectivity via donor-acceptor interaction with the catalyst and up to 9% enhancement of ee value was observed in a favorable case.