Details

Autor(en) / Beteiligte

• Sandoval, Braddock A.
• Kurtoic, Sarah I.
• Chung, Megan M.
• Biegasiewicz, Kyle F.
• Hyster, Todd K.

Titel

Photoenzymatic Catalysis Enables Radical‐Mediated Ketone Reduction in Ene‐Reductases

Ist Teil von

• Angewandte Chemie, 2019-06, Vol.131 (26), p.8806-8810

Ort / Verlag

Weinheim: Wiley Subscription Services, Inc

Erscheinungsjahr

2019

Quelle

Wiley Blackwell Single Titles

Beschreibungen/Notizen

• Flavin‐dependent ene‐reductases (EREDs) are known to stereoselectively reduce activated alkenes, but are inactive toward carbonyls. Demonstrated here is that in the presence of photoredox catalysts, these enzymes will reduce aromatic ketones. Mechanistic experiments suggest this reaction proceeds through ketyl radical formation, a reaction pathway that is distinct from the native hydride‐transfer mechanism. Furthermore, this reactivity is accessible without modification of either the enzyme or cofactors, allowing both native and non‐natural mechanisms to occur simultaneously. Based on control experiments, we hypothesize that binding to the enzyme active site attenuates the reduction potential of the substrate, enabling single‐electron reduction. This reactivity highlights opportunities to access new catalytic manifolds by merging photoredox catalysis with biocatalysis. Der Zusammenschluss von Photokatalyse und Biokatalyse führt zu einer neuen chemischen Reaktivität für flavinabhängige En‐Reduktasen. Mechanistische Studien stützen einen Mechanismus, bei dem enantiomerenangereicherte Alkohole durch Wasserstoffatomtransfer von Flavin zum Ketylrest gebildet werden.