In biocatalysis, unspecific peroxygenases (UPO) are a promising class of enzymes. They enable regio-and-enantioselective oxyfunctionalizations with minimal hydrogen peroxide, without needing additional cofactors. However, adding excessive H2O2 externally can denature enzymes, and its industrial, high-grade production is energy intensive. Thankfully, H2O2 can be produced in situ by gold-palladium catalysts at room temperature in water under low H2 pressure. Freakley et al. recently showed that combining Au-Pd catalysts with UPO enables one-pot cascade reactions without interference between catalysts.2 Learning from their work, and leaning on our group’s experience in the fabrication of chemo-enzymatic heterogeneous catalysts (HCEHC)3,4 we recreated those Au-Pd catalysts and combined them with a commercial UPO (PaDa-I) in a single solid material. The resulting HCEHC was shown to be reusable and highly stereo-and regioselective for the hydroxylation of ethylbenzene to (R)-phenylethanol. A single gram per liter of the most active HCEHC manages the full conversion of 14mM of ethylbenzene in less than 4 hours. This is roughly 40% higher than other reported cascade systems, which require extra biocatalytic steps and expensive cofactors1. Our current work now focuses on the improvement of the hybridization process to enhance the activity, stability, and shelf life of this novel HCEHC, while reducing its production cost. 1. Hobisch, M. et al. Recent developments in the use of peroxygenases – Exploring their high potential in selective oxyfunctionalisations. Biotechnology Advances 51, 107615 (2021). 2. Freakley, S. J. et al. A chemo-enzymatic oxidation cascade to activate C–H bonds with in situ generated H2O2. Nat Commun 10, 4178 (2019). 3. Smeets, V. et al. Hollow zeolite microspheres as a nest for enzymes: a new route to hybrid heterogeneous catalysts. Chem. Sci. 11, 954–961 (2020). 4. Debecker, D. P. et al. Hybrid chemoenzymatic heterogeneous catalysts. Curr. Opinion Green Sus. Chem. 28, 100437 (2021).
Kinnaer et al. (Wed,) studied this question.