Chloroperoxidase-Catalyzed Oxidation of 5-Hydroxymethylfurfural

Abstract Chloroperoxidase (CPO) catalyzes the oxidation of 5-hydroxymethylfurfural (HMF) with hydrogen peroxide as the oxidant. The reaction proceeds with 60–74% selectivity to furan-2,5-dicarboxaldehyde (FDC). The main byproduct is 5-hydroxy-methyl-2-furancarboxylic acid (HFCA); a minor amount of 5-formylfuran-2-carboxylic acid (FFCA) was also detected. When H2 18O2 was used a virtually quantitative incorporation of 18O was observed in the HFCA product, whereas no 18O was incorporated from H2 18O. Hence, the CPO-catalyzed oxidation of aldehydes to acids proceeds with direct oxygen transfer from the iron-oxo complex of CPO. Controlling the H2O2-addition with a H2O2-stat facilitated the reaction procedure and a conversion of 87% of HMF was reached within 21 min.