Visible light mediated aerobic oxidative hydroxylation of 2-oxindole-3-carboxylate esters: an alternative approach to 3-hydroxy-2-oxindoles

Abstract

A convenient aerobic oxidative hydroxylation of 3-substituted oxindoles under mild reaction conditions is described herein. This process was accomplished by the activation of molecular oxygen in the air in the presence of a photocatalyst under the irradiation of visible light. The desired product was delivered in up to 89% yield without the addition of base or stoichiometric oxidant.