Laccase-catalyzed in situ generation and regeneration of N-phenyltriazolinedione for the aerobic oxidative homo-coupling of thiols to disulfides

The first report on aerobic in situ generation and regeneration of N-phenyltriazolinedione, a valuable oxidizing agent, from a catalytic amount of N-phenyl urazole in the presence of a laccase enzyme is presented. The application of a 4-phenyl urazole/Laccase/O-2 as a new cooperative catalytic oxidation system is reported for a transition-metal-free and halogen free oxidative homo-coupling reaction of structurally diverse thiols to their corresponding disulfides with good to excellent yields in a phosphate buffer solution under mild reaction conditions.