Aerobic oxidation of C-H bonds to carboxylic acids enabled by decatungstate photocatalysis

Abstract

Direct aerobic oxidation of p-xylene using cobalt, manganese and bromide ion catalyst system, named the Amoco method, is a fundamentally important process to produce terephthalic acid in industry. However, it still suffers from harsh conditions and potential environmental pollution. Herein, we disclose an aerobic oxidation of alkyl aromatics to carboxylic acids through decatungstate photocatalysis featuring mild and green conditions (i.e., ambient temperature, visible light irradiation and atmospheric O2 as the green oxidant). It is scalable for the synthesis of terephthalic acid, which shows a significant potential for industrial production. Various substituted toluene derivatives were well applicable, thus furnishing acid and ester products in good yields.

Keywords

• Aerobic oxidation
• Decatungstate photocatalysis
• Terephthalic acid
• Alkyl aromatics
• Carboxylic acids