Room temperature Baeyer–Villiger oxidation using molecular oxygen over mesoporous zirconium phosphate

Abstract

Lactones have found wide applications as key molecules for the synthesis of important bioactive compounds, natural products and polymers; and represent a valuable family of synthons for various organic transformations. A series of lactones or esters are synthesized from their corresponding ketones employing Baeyer–Villiger (BV) oxidation at room temperature using mesoporous zirconium phosphate (m-ZrP) as a solid acid catalyst, molecular oxygen (O₂)/benzaldehyde as an oxidizing agent, in a solvent free reaction medium. The oxidation reaction is studied in detail by varying the reaction parameters like molar ratio of the reactants, reaction temperature, time and catalyst loading. The m-ZrP showed high catalytic activity for the BV oxidation of cyclohexanone as well as other ketones in the presence of reduced amount of benzaldehyde with 100% selectivity for the corresponding lactones/esters. The protocol is suitable even for bulkier cyclic ketones like adamantanone. The m-ZrP catalyst showed excellent reusability.