The photocatalytic oxidation of NADH using a flavin photocatalyst and a simple blue LED light source is reported.

An increasing number of biocatalytic oxidation reactions rely on H 2 O 2 as a clean oxidant. The poor robustness of most enzymes towards H 2 O 2 , however, necessitates more efficient systems for in situ H 2 O 2 generation. In analogy to the well‐known formate dehydrogenase to promote NADH‐dependent reactions, we here propose employing formate oxidase (FOx) to promote H 2 O 2 ‐dependent enzymatic oxidation reactions. Even under non‐optimised conditions, high turnover numbers for coupled FOx/peroxygenase catalysis were achieved.

Biocatalytic oxyfunctionalisation reactions are traditionally conducted in aqueous media limiting their production yield. Here we report the application of a peroxygenase in neat reaction conditions reaching product concentrations of up to 360 mM.

Natural deep eutectic solvents (NADES) are proposed as alternative solvents for peroxygenase‐catalysed oxyfunctionalization reactions. Choline chloride‐based NADES are of particular interest as they can serve as solvent, enzyme‐stabiliser and sacrificial electron donor for the in situ H2O2 generation. This report provides the first proof‐of‐concept and basic characterisation of this new reaction system. Highly promising turnover numbers for the biocatalysts of up to 200,000 have been achieved.

We report visible light-driven, asymmetric hydrogenation of CC bonds using an ene-reductase from Thermus scotoductus SA-01 (TsOYE) and a light-harvesting dye (rose bengal, RB) co-immobilized in an alginate hydrogel. Highly efficient encapsulation of RB in alginate hydrogel was achieved using the intrinsic affinity between TsOYE and RB, which allowed for the construction of robust RB-TsOYEloaded alginate capsules. In the absence of NADH, the photobiocatalytic system facilitated asymmetric reduction of 2-methylcyclohexenone to an enantiopure (R)-2-methylcyclohexanone (ee > 99%; max. conversion, 70.4%; turnover frequency, 1.54 min −1 ; turnover number, 300.2) under illumination. A series of stability tests revealed a significant enhancement of TsOYE's robustness in alginate hydrogel against heat and chemical denaturants. This study provides insight into a greener and sustainable approach of cofactor-free OYE catalysis for producing value-added chemicals using light energy.