A chemo-enzymatic oxidation cascade to activate C-H bonds with in situ generated H₂O₂

Continuous low-level supply or in situ generation of hydrogen peroxide (H₂O₂) is essential for the stability of unspecific peroxygenases, which are deemed ideal biocatalysts for the selective activation of C-H bonds. To envisage potential large scale applications of combined catalytic systems the reactions need to be simple, efficient and produce minimal by-products. We show that gold-palladium nanoparticles supported on TiO₂ or carbon have sufficient activity at ambient temperature and pressure to generate H₂O₂ from H₂ and O₂ and supply the oxidant to the engineered unspecific heme-thiolate peroxygenase PaDa-I. This tandem catalyst combination facilitates efficient oxidation of a range of C-H bonds to hydroxylated products in one reaction vessel with only water as a by-product under conditions that could be easily scaled.