Switching between enantiomers by combining chromoselective photocatalysis and biocatalysis Schmermund, Luca Reischauer, Susanne Bierbaumer, Sarah Winkler, Christoph Diaz-Rodriguez, Alba Edwards, Lee J. Kara, Selin Mielke, Tamara Cartwright, Jared Grogan, Gideon Pieber, Bartholomäus ; https://orcid.org/0000-0001-8689-388X Kroutil, Wolfgang Controlling the selectivity of a chemical reaction with external stimuli is common in thermal processes, but rare in visible-light photocatalysis. Here we show that the redox potential of a carbon nitride photocatalyst (CN-OA-m) can be tuned by changing the irradiation wavelength to generate electron holes with different oxidation potentials. This tuning was the key to realizing photo-chemo-enzymatic cascades that give either the (S)- or the (R)-enantiomer of phenylethanol. In combination with an unspecific peroxygenase from Agrocybe aegerita, green light irradiation of CN-OA-m led to the enantioselective hydroxylation of ethylbenzene to (R)-1-phenylethanol (99% ee). In contrast, blue light irradiation triggered the photocatalytic oxidation of ethylbenzene to acetophenone, which in turn was enantioselectively reduced with an alcohol dehydrogenase from Rhodococcus ruber to form (S)-1-phenylethanol (93% ee). ChemRxiv 2021 info:eu-repo/semantics/preprint doc-type:preprint text http://purl.org/coar/resource_type/c_816b https://research-explorer.ista.ac.at/record/12070 Schmermund L, Reischauer S, Bierbaumer S, et al. Switching between enantiomers by combining chromoselective photocatalysis and biocatalysis. doi:<a href="https://doi.org/10.26434/chemrxiv.13521527">10.26434/chemrxiv.13521527</a> eng info:eu-repo/semantics/altIdentifier/doi/10.26434/chemrxiv.13521527 info:eu-repo/semantics/openAccess