Chromoselective Photocatalysis Enables Stereocomplementary Biocatalytic Pathways

Controlling chemical reaction selectivity with external stimuli is common in thermal processes but less explored in visible-light photocatalysis. We show that tuning the redox potential of a carbon nitride photocatalyst (CN-OA-m) via irradiation wavelength enables photo-chemo-enzymatic cascades yielding either (S)- or (R)-enantiomers of phenylethanol. Green light with CN-OA-m and Agrocybe aegerita peroxygenase achieved enantioselective hydroxylation of ethylbenzene to (R)-1-phenylethanol (99% ee), while blue light induced ethylbenzene oxidation to acetophenone, reduced by Rhodococcus ruber alcohol dehydrogenase to (S)-1-phenylethanol (93% ee).