Description:
<jats:title>Abstract</jats:title><jats:p>H<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub>‐driven enzymes are of great interest for industrial biotransformations. Herein, we show for the first time that oxalate oxidase (OXO) is an efficient in situ source of H<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub> for one of these biocatalysts, which is known as unspecific peroxygenase (UPO). OXO is reasonably robust, produces only CO<jats:sub>2</jats:sub> as a by‐product and uses oxalate as a cheap sacrificial electron donor. UPO has significant potential as an industrial catalyst for selective C−H oxyfunctionalisations, as we confirm herein by testing a diverse drug panel using miniaturised high‐throughput assays and mass spectrometry. 33 out of 64 drugs were converted in 5 μL‐scale reactions by the UPO with OXO (conversion >70 % for 11 drugs). Furthermore, oxidation of the drug tolmetin was achieved on a 50 mg scale (TON<jats:sub>UPO</jats:sub> 25 664) with 84 % yield, which was further improved via enzyme immobilization. This one‐pot approach ensures adequate H<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub> levels, enabling rapid access to industrially relevant molecules that are difficult to obtain by other routes.</jats:p>