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Steering oxygen-centred radicals with ground-state ene-reductases for enantioselective intermolecular hydroalkoxylations

Nature Catalysis volume 8, pages 740–748 (2025)Cite this article

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Abstract

Enzymes are emerging as promising catalysts for selective radical transformations. However, non-natural radical-type enzymatic catalysis is currently limited to utilizing C-, N- and S-centred radical species. Alkoxy radicals are recognized as versatile intermediates with high reactivity, typically engaging in reactivity modes such as hydrogen atom transfer, β-scission processes and intramolecular addition to alkenes. Enantioselective intermolecular alkoxy radical addition to alkenes remained unknown. Here we develop a biocatalytic strategy based on engineered ene-reductases that facilitate the radical hydroalkoxylation of oxygen-centred radicals with alkenes. A single, ground-state ene-reductase adeptly controls the biocompatible generation of O-radicals, the follow-up intermolecular O-radical addition to alkenes and the final prochiral C-radical termination, achieving high chemo- and enantioselectivity (both enantiomers are obtained separately with different enzymes). Mechanistic experiments, including computational simulations, reveal that the radical enzymatic reaction initiates via a ground-state single-electron transfer and elucidate the origins of enantiodiscrimination of the overall reaction.

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Fig. 1: ER-enabled enantioselective radical biocatalysis.
Fig. 2: Reaction development.
Fig. 3: Scope investigation.
Fig. 4: Proposed catalytic cycle under dark conditions.
Fig. 5: Mechanistic studies.

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Data availability

HPLC spectra and NMR spectra are available in the Supplementary Information. The PDB code of the GluER used in this work is 6O08. The structural data (including all QM calculation coordinates, QM region coordinates from QM/MM calculations and the initial and final configurations of molecular dynamics trajectories) are available via Zenodo at https://doi.org/10.5281/zenodo.14851048 (ref. 67).

Code availability

The codes for building the QSAR model are available via GitHub at https://github.com/ld139/QSAR_enz.

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Acknowledgements

This work was supported by the National Key Research and Development Program of China (grant number 2022YFA0913000 to X.H.), the National Natural Science Foundation of China (grant numbers 22277053 to X.H., 22121001 to B.W. and 224B2705 to B.Z.), the Fundamental Research Funds for the Central Universities (grant numbers 0205/14380346 and 0205/14380351 to X.H.) and the Excellent Research Program of Nanjing University (grant number ZYJH004), the State Key Laboratory of Microbial Technology Open Projects Fund (M2023-01 to B.W.).

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Author notes

  1. These authors contributed equally: Bin Chen, Qiaoyu Zhang, Jinhai Yu.

Authors and Affiliations

  1. State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), Frontier Interdisciplinary Science Research Center, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, China

    Bin Chen, Jinhai Yu, Beibei Zhao, Ran Ge, Zihan Zhang & Xiaoqiang Huang

  2. State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China

    Qiaoyu Zhang, Ding Luo & Binju Wang

  3. Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, China

    Ran Ge

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Contributions

B.C. envisioned and developed the reaction. B.Z. assisted with synthetic experiments. J.Y. and R.G. created mutations and expressed proteins. Q.Z., D.L. and B.W. conducted computational studies. Z.Z. reproduced selected examples. B.C., Q.Z., B.W. and X.H. wrote the paper with input from all authors. X.H. coordinated and conceived the project.

Corresponding authors

Correspondence to Binju Wang or Xiaoqiang Huang.

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Chen, B., Zhang, Q., Yu, J. et al. Steering oxygen-centred radicals with ground-state ene-reductases for enantioselective intermolecular hydroalkoxylations. Nat Catal 8, 740–748 (2025). https://doi.org/10.1038/s41929-025-01372-z

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