Abstract

Palladium-catalysed cross-coupling reactions, central tools in fine-chemical synthesis, predominantly employ soluble metal complexes despite recognized challenges with product purification and catalyst reusability1,2,3. Attempts to tether these homogeneous catalysts on insoluble carriers have been thwarted by suboptimal stability, which leads to a progressively worsening performance due to metal leaching or clustering4. The alternative application of supported Pd nanoparticles has faced limitations because of insufficient activity under the mild conditions required to avoid thermal degradation of the substrates or products. Single-atom heterogeneous catalysts lie at the frontier5,6,7,8,9,10,11,12,13,14,15,16,17,18. Here, we show that the Pd atoms anchored on exfoliated graphitic carbon nitride (Pd-ECN) capture the advantages of both worlds, as they comprise a solid catalyst that matches the high chemoselectivity and broad functional group tolerance of state-of-the-art homogeneous catalysts for Suzuki couplings, and also demonstrate a robust stability in flow. The adaptive coordination environment within the macroheterocycles of ECN facilitates each catalytic step. The findings illustrate the exciting opportunities presented by nanostructuring single atoms in solid hosts for catalytic processes that remain difficult to heterogenize.

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Acknowledgements

We thank ETH Zurich, the Swiss National Science Foundation (Grant no. 200021-169679) and MINECO (CTQ2015-68770-R) for financial support. E.F. thanks MINECO La Caixa-Severo Ochoa for a predoctoral grant through Severo Ochoa Excellence Accreditation 2014-2018 (SEV-2013-0319). M.A.O. acknowledges the Juan de la Cierva-Incorporación postdoctoral program (IJCI-2016-29762). S.M.C. acknowledges support from the Henslow Research Fellowship at Girton College, Cambridge. P.A.M. acknowledges the EPSRC (Grant no. EP/R008779/1) for funding. We thank ScopeM at ETH Zurich for access to its facilities, BSC-RES for providing generous computational resources, Diamond Light Source for access and support in the use of the electron Physical Science Imaging Centre (EM16967), R. Hauert for XPS measurements, D. N. Johnstone for assistance in acquiring data at ePSIC. G.V. and S.R. thank T. Weller (Idorsia Pharmaceuticals Ltd.) for his constant support.

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Author notes

  1. These authors contributed equally: Zupeng Chen, Evgeniya Vorobyeva.

Affiliations

  1. Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zürich, Zürich, Switzerland

    • Zupeng Chen
    • , Evgeniya Vorobyeva
    • , Sharon Mitchell
    •  & Javier Pérez-Ramírez
  2. Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology, Tarragona, Spain

    • Edvin Fako
    • , Manuel A. Ortuño
    •  & Núria López
  3. Department of Materials Science and Metallurgy, University of Cambridge, Cambridge, UK

    • Sean M. Collins
    •  & Paul A. Midgley
  4. Chemistry Technologies and Lead Discovery, Department of Drug Discovery and Clinical Development, Idorsia Pharmaceuticals Ltd, Allschwil, Switzerland

    • Sylvia Richard
    •  & Gianvito Vilé

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Contributions

J. P.-R. conceived and coordinated all stages of this research. E.V. and Z.C. prepared and characterized the catalysts. G.V. and S.R. undertook the catalytic tests. E.F., M.A.O. and N.L. conducted the computational studies. S.M.C. and P.A.M. conducted the AC-STEM analysis. Z.C., E.V., S.M., G.V., E F., N.L. and J P.-R. co-wrote the manuscript in discussion with other co-authors.

Competing interests

The authors declare no competing interests.

Corresponding author

Correspondence to Javier Pérez-Ramírez.

Supplementary information

  1. Supplementary Information

    Supplementary Figures 1–13, Supplementary Tables 1–7, Supplementary Methods and Supplementary References

  2. Supplementary Video 1

    Molecular dynamics simulation tracking the trajectory of a single Pd atom in a first principles run

  3. Supplementary Video 2

    Animation following the path for the Suzuki reaction with the Pd-ECN catalyst during the individual elementary steps calculated by DFT

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DOI

https://doi.org/10.1038/s41565-018-0167-2