Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

Palladium-catalysed electrophilic aromatic C–H fluorination

Abstract

Aryl fluorides are widely used in the pharmaceutical and agrochemical industries1,2, and recent advances have enabled their synthesis through the conversion of various functional groups. However, there is a lack of general methods for direct aromatic carbon–hydrogen (C–H) fluorination3. Conventional methods require the use of either strong fluorinating reagents, which are often unselective and difficult to handle, such as elemental fluorine, or less reactive reagents that attack only the most activated arenes, which reduces the substrate scope. A method for the direct fluorination of aromatic C–H bonds could facilitate access to fluorinated derivatives of functional molecules that would otherwise be difficult to produce. For example, drug candidates with improved properties, such as increased metabolic stability or better blood–brain-barrier penetration, may become available. Here we describe an approach to catalysis and the resulting development of an undirected, palladium-catalysed method for aromatic C–H fluorination using mild electrophilic fluorinating reagents. The reaction involves a mode of catalysis that is unusual in aromatic C–H functionalization because no organometallic intermediate is formed; instead, a reactive transition-metal-fluoride electrophile is generated catalytically for the fluorination of arenes that do not otherwise react with mild fluorinating reagents. The scope and functional-group tolerance of this reaction could provide access to functional fluorinated molecules in pharmaceutical and agrochemical development that would otherwise not be readily accessible.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Aromatic fluorination catalysed by 1.
Figure 2: Substrate scope of the Pd-catalysed fluorination of arenes.
Figure 3: Mechanism of fluorination catalysed by 1.
Figure 4: Comparison of the positional selectivity of stoichiometric and catalytic fluorinations using 2′.

Similar content being viewed by others

References

  1. Müller, K., Faeh, C. & Diederich, F. Fluorine in pharmaceuticals: looking beyond intuition. Science 317, 1881–1886 (2007)

    Article  ADS  Google Scholar 

  2. Gillis, E. P., Eastman, K. J., Hill, M. D., Donnelly, D. J. & Meanwell, N. A. Applications of fluorine in medicinal chemistry. J. Med. Chem. 58, 8315–8359 (2015)

    Article  CAS  Google Scholar 

  3. Campbell, M. G. & Ritter, T. Modern carbon–fluorine bond forming reactions for aryl fluoride synthesis. Chem. Rev. 115, 612–633 (2015)

    Article  CAS  Google Scholar 

  4. Sandford, G. Elemental fluorine in organic chemistry (1997–2006). J. Fluor. Chem. 128, 90–104 (2007)

    Article  CAS  Google Scholar 

  5. Taylor, S. D., Kotoris, C. C. & Hum, G. Recent advances in electrophilic fluorination. Tetrahedron 55, 12431–12477 (1999)

    Article  CAS  Google Scholar 

  6. Lal, G. S., Pez, G. P. & Syvret, R. G. Electrophilic NF fluorinating agents. Chem. Rev. 96, 1737–1756 (1996)

    Article  CAS  Google Scholar 

  7. Fier, P. S. & Hartwig, J. F. Selective C–H fluorination of pyridines and diazines inspired by a classic amination reaction. Science 342, 956–960 (2013)

    Article  CAS  ADS  Google Scholar 

  8. Chan, K. S. L., Wasa, M., Wang, X. & Yu, J.-Q. Palladium(ii)-catalyzed selective monofluorination of benzoic acids using a practical auxiliary: a weak-coordination approach. Angew. Chem. Int. Ed. 50, 9081–9084 (2011)

    Article  CAS  Google Scholar 

  9. Wang, X., Mei, T.-S. & Yu, J.-Q. Versatile Pd(OTf)2·2H2O-catalyzed ortho-fluorination using NMP as a promoter. J. Am. Chem. Soc. 131, 7520–7521 (2009)

    Article  CAS  Google Scholar 

  10. Hull, K. L., Anani, W. Q. & Sanford, M. S. Palladium-catalyzed fluorination of carbon–hydrogen bonds. J. Am. Chem. Soc. 128, 7134–7135 (2006)

    Article  CAS  Google Scholar 

  11. Liu, W. et al. Oxidative aliphatic C–H fluorination with fluoride ion catalyzed by a manganese porphyrin. Science 337, 1322–1325 (2012)

    Article  CAS  ADS  Google Scholar 

  12. Mkhalid, I. A. I., Barnard, J. H., Marder, T. B., Murphy, J. M. & Hartwig, J. F. C–H activation for the construction of C–B bonds. Chem. Rev. 110, 890–931 (2010)

    Article  CAS  Google Scholar 

  13. Cheng, C. & Hartwig, J. F. Rhodium-catalyzed intermolecular C–H silylation of arenes with high steric regiocontrol. Science 343, 853–857 (2014)

    Article  CAS  ADS  Google Scholar 

  14. Wang, P. et al. Ligand-accelerated non-directed C–H functionalization of arenes. Nature 551, 489–493 (2017)

    Article  CAS  ADS  Google Scholar 

  15. Kuhl, N., Hopkinson, M. N., Wencel-Delord, J. & Glorius, F. Beyond directing groups: transition-metal-catalyzed C–H activation of simple arenes. Angew. Chem. Int. Ed. 51, 10236–10254 (2012)

    Article  CAS  Google Scholar 

  16. Alvarez, S. A cartography of the van der Waals territories. Dalton Trans. 42, 8617–8636 (2013)

    Article  CAS  Google Scholar 

  17. Regalado, E. L., Makarov, A. A., McClain, R., Przybyciel, M. & Welch, C. J. Search for improved fluorinated stationary phases for separation of fluorine-containing pharmaceuticals from their desfluoro analogs. J. Chromatogr. A 1380, 45–54 (2015)

    Article  CAS  Google Scholar 

  18. Regalado, E. L. et al. Support of academic synthetic chemistry using separation technologies from the pharmaceutical industry. Org. Biomol. Chem. 12, 2161–2166 (2014)

    Article  CAS  Google Scholar 

  19. Hyohdoh, I. et al. Fluorine scanning by nonselective fluorination: enhancing Raf/MEK inhibition while keeping physicochemical properties. ACS Med. Chem. Lett. 4, 1059–1063 (2013)

    Article  CAS  Google Scholar 

  20. Cernak, T ., Dykstra, K. D ., Tyagarajan, S ., Vachal, P. & Krska, S. W. The medicinal chemist’s toolbox for late stage functionalization of drug-like molecules. Chem. Soc. Rev. 45, 546–576 (2016); erratum 46, 1760 (2017)

    Article  CAS  Google Scholar 

  21. McCall, A. S. & Kraft, S. Pyridine-assisted chlorinations and oxidations by palladium(iv). Organometallics 31, 3527–3538 (2012)

    Article  CAS  Google Scholar 

  22. McCall, A. S., Wang, H., Desper, J. M. & Kraft, S. Bis-N-heterocyclic carbene palladium(iv) tetrachloride complexes: synthesis, reactivity, and mechanisms of direct chlorinations and oxidations of organic substrates. J. Am. Chem. Soc. 133, 1832–1848 (2011)

    Article  CAS  Google Scholar 

  23. Geng, C., Du, L., Liu, F., Zhu, R. & Liu, C. Theoretical study on the mechanism of selective fluorination of aromatic compounds with Selectfluor. RSC Adv. 5, 33385–33391 (2015)

    Article  CAS  Google Scholar 

  24. Brandt, J. R., Lee, E., Boursalian, G. B. & Ritter, T. Mechanism of electrophilic fluorination with Pd(iv): fluoride capture and subsequent oxidative fluoride transfer. Chem. Sci. 5, 169–179 (2014)

    Article  CAS  Google Scholar 

  25. Groves, J. T. High-valent iron in chemical and biological oxidations. J. Inorg. Biochem. 100, 434–447 (2006)

    Article  CAS  Google Scholar 

  26. McNeill, E. & Du Bois, J. Ruthenium-catalyzed hydroxylation of unactivated tertiary C–H bonds. J. Am. Chem. Soc. 132, 10202–10204 (2010)

    Article  CAS  Google Scholar 

  27. Chen, M. S. & White, M. C. A predictably selective aliphatic C–H oxidation reaction for complex molecule synthesis. Science 318, 783–787 (2007)

    Article  CAS  ADS  Google Scholar 

  28. Liu, W. & Groves, J. T. Manganese catalyzed C–H halogenation. Acc. Chem. Res. 48, 1727–1735 (2015)

    Article  CAS  Google Scholar 

  29. Du Bois, J. Rhodium-catalyzed C–H amination. An enabling method for chemical synthesis. Org. Process Res. Dev. 15, 758–762 (2011)

    CAS  PubMed  Google Scholar 

  30. Boursalian, G. B., Ngai, M.-Y., Hojczyk, K. N. & Ritter, T. Pd-catalyzed aryl C–H imidation with arene as the limiting reagent. J. Am. Chem. Soc. 135, 13278–13281 (2013)

    Article  CAS  Google Scholar 

  31. Paudyal, M. P. et al. Dirhodium-catalyzed C–H arene amination using hydroxylamines. Science 353, 1144–1147 (2016)

    Article  CAS  ADS  Google Scholar 

Download references

Acknowledgements

We thank L. Gitlin for HPLC purification, R. Goddard, S. Palm and J. Rust for X-ray crystallographic analysis, C. Farès for NMR spectroscopy, and M. Blumenthal, D. Kampen and S. Marcus for mass spectrometry. We thank UCB Biopharma for funding and compound separation, the Japan Society for the Promotion of Science and L’Oréal-UNESCO Japan for graduate fellowships to K.Y., the Fonds der Chemischen Industrie for a graduate fellowship for J.D.R., and the German Academic Exchange Service, DAAD for an Otto-Bayer fellowship to J.C.B.

Author information

Authors and Affiliations

Authors

Contributions

K.Y. designed catalyst 1 and optimized the fluorination reaction. K.Y. and J.D.R. conducted mechanistic studies. K.Y. and G.B.B. developed the conceptual approach to the project. J.L., J.A.O.G., J.C.B., K.Y. and J.D.R. explored the substrate scope. J.D.R. performed DFT calculations with input from M.v.G. and F.N. G.B.B. wrote the manuscript with input from all other authors. C.G. and J.J. supported development towards useful examples. K.Y., J.L., J.A.O.G., G.B.B., J.D.R. and T.R. analysed the data. T.R. directed the project.

Corresponding author

Correspondence to Tobias Ritter.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Additional information

Reviewer Information Nature thanks J. Groves and the other anonymous reviewer(s) for their contribution to the peer review of this work.

Publisher's note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

This file contains procedures and characterization as well as spectra. (PDF 10929 kb)

Supplementary Data

This file contains checkcif 4na containing proof of appropriate x-ray data. (PDF 98 kb)

Supplementary Data

This file contains checkcif 4nb containing proof of appropriate x-ray data. (PDF 72 kb)

PowerPoint slides

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Yamamoto, K., Li, J., Garber, J. et al. Palladium-catalysed electrophilic aromatic C–H fluorination. Nature 554, 511–514 (2018). https://doi.org/10.1038/nature25749

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nature25749

This article is cited by

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing