Download MendeleyPhotoexcitation of flavoenzymes enables a stereoselective radical cyclization.
Biegasiewicz, K.F., Cooper, S.J., Gao, X., Oblinsky, D.G., Kim, J.H., Garfinkle, S.E., Joyce, L.A., Sandoval, B.A., Scholes, G.D., Hyster, T.K.(2019) Science 364: 1166-1169
- PubMed: 31221855
- DOI: https://doi.org/10.1126/science.aaw1143
- Primary Citation of Related Structures:
6MYW, 6O08 - PubMed Abstract:
Photoexcitation is a common strategy for initiating radical reactions in chemical synthesis. We found that photoexcitation of flavin-dependent "ene"-reductases changes their catalytic function, enabling these enzymes to promote an asymmetric radical cyclization. This reactivity enables the construction of five-, six-, seven-, and eight-membered lactams with stereochemical preference conferred by the enzyme active site. After formation of a prochiral radical, the enzyme guides the delivery of a hydrogen atom from flavin-a challenging feat for small-molecule chemical reagents. The initial electron transfer occurs through direct excitation of an electron donor-acceptor complex that forms between the substrate and the reduced flavin cofactor within the enzyme active site. Photoexcitation of promiscuous flavoenzymes has thus furnished a previously unknown biocatalytic reaction.
Organizational Affiliation:
Department of Chemistry, Princeton University, Princeton, NJ 08544, USA.
