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Chromoselective Photocatalysis Enables Stereocomplementary Biocatalytic Pathways*
Luca Schmermund1, Susanne Reischauer2, Sarah Bierbaumer1
1Institute of Chemistry, Department of Organic and Bioorganic Chemistry, University of Graz, NAWI Graz, BioTechMed Graz, Heinrichstrasse 28, 8010, Graz, Austria.
Angewandte Chemie (International Ed. in English)
|February 2, 2021
Summary
Researchers tuned photocatalyst redox potential using light wavelength. This enabled selective synthesis of either (R)- or (S)-phenylethanol enantiomers via photo-chemo-enzymatic cascades.
Area of Science:
- Chemical catalysis
- Photochemistry
- Biocatalysis
Background:
- Controlling chemical reaction selectivity with external stimuli is challenging in visible-light photocatalysis.
- Tuning the redox potential of photocatalysts is crucial for selective transformations.
Purpose of the Study:
- To demonstrate wavelength-dependent tuning of a carbon nitride photocatalyst's redox potential.
- To achieve enantioselective synthesis of phenylethanol isomers using photo-chemo-enzymatic cascades.
Main Methods:
- Utilized a carbon nitride photocatalyst (CN-OA-m) with tunable redox potential via irradiation wavelength.
- Employed visible-light photocatalysis in combination with enzymatic catalysis (peroxygenase and alcohol dehydrogenase).
Main Results:
- Green light irradiation of CN-OA-m led to enantioselective hydroxylation of ethylbenzene to (R)-1-phenylethanol (99% ee).
- Blue light irradiation of CN-OA-m oxidized ethylbenzene to acetophenone, followed by enantioselective reduction to (S)-1-phenylethanol (93% ee).
Conclusions:
- Demonstrated precise control over enantioselectivity in chemical synthesis by tuning photocatalyst redox potential with light wavelength.
- Established a novel photo-chemo-enzymatic cascade strategy for accessing specific chiral alcohol enantiomers.
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