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.

  • Article
  • Published:

Catalytic radical generation of π-allylpalladium complexes

Abstract

Transition metal catalysed allylic substitution is one of the most powerful and frequently used methods in organic synthesis. In particular, palladium-catalysed allylic functionalization has become a well-established strategy for constructing carbon–carbon or carbon–heteroatom bonds, and its utility has been demonstrated in natural product synthesis, drug discovery and materials science. Several methods have been developed to generate π-allylpalladium complexes through ionic mechanisms; however, these methods typically require either prefunctionalized starting materials or stoichiometric oxidants, which naturally limits their scope. Here, we show a radical approach for the generation of π-allylpalladium complexes by employing N-hydroxyphthalimide esters as bifunctional reagents in combination with 1,3-dienes. Using this strategy, we report the 1,4-aminoalkylation of dienes. The remarkable scope and functional group tolerance of this redox-neutral and mild protocol was demonstrated across >60 examples. The utility of this strategy was further demonstrated in radical cascade reactions and in the late-stage modification of drugs and natural products.

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

Fig. 1: Development of a radical strategy for the generation of π-allylpalladium complexes and its application in the 1,4-aminoalkylation of dienes.
Fig. 2: Scope of palladium-catalysed 1,4-aminoalkylation of 1,3-dienes.
Fig. 3: Modification of complex architectures.
Fig. 4: Cascade reactions and manipulation of allylic amines.
Fig. 5: Preliminary mechanistic studies and proposed mechanism.

Similar content being viewed by others

Data availability

Materials and methods, detailed optimization studies, experimental procedures, mechanistic studies, EPR spectra and NMR spectra are available in the Supplementary Information or from the corresponding author upon reasonable request. The atomic coordinates of the optimized models are provided in Supplementary Data 1. Crystallographic data for compound 20 are available free of charge from the Cambridge Crystallographic Data Centre under deposition number CCDC 1947092. Copies of the data can be obtained free of charge via https://www.ccdc.cam.ac.uk/structures/.

References

  1. Trost, B. The atom economy—a search for synthetic efficiency. Science 254, 1471–1477 (1991).

    CAS  PubMed  Google Scholar 

  2. Wender, P. A. & Miller, B. L. Synthesis at the molecular frontier. Nature 460, 197–201 (2009).

    CAS  PubMed  PubMed Central  Google Scholar 

  3. Young, I. S. & Baran, P. S. Protecting-group-free synthesis as an opportunity for invention. Nat. Chem. 1, 193–205 (2009).

    CAS  PubMed  Google Scholar 

  4. Blakemore, D. C. et al. Organic synthesis provides opportunities to transform drug discovery. Nat. Chem. 10, 383–394 (2018).

    CAS  PubMed  Google Scholar 

  5. Trost, B. M. & Van Vranken, D. L. Asymmetric transition metal-catalyzed allylic alkylations. Chem. Rev. 96, 395–422 (1996).

    CAS  PubMed  Google Scholar 

  6. Trost, B. M. & Crawley, M. L. Asymmetric transition-metal-catalyzed allylic alkylations: applications in total synthesis. Chem. Rev. 103, 2921–2944 (2003).

    CAS  PubMed  Google Scholar 

  7. Lu, Z. & Ma, S. Metal-catalyzed enantioselective allylation in asymmetric synthesis. Angew. Chem. Int. Ed. 47, 258–297 (2008).

    CAS  Google Scholar 

  8. Cheng, Q. et al. Iridium-catalyzed asymmetric allylic substitution reactions. Chem. Rev. 119, 1855–1969 (2019).

    CAS  PubMed  Google Scholar 

  9. Kazmaier, U. Transition Metal Catalyzed Enantioselective Allylic Substitution in Organic Synthesis (Springer, 2012).

  10. Parisotto, S. & Deagostino, A. π-allylpalladium complexes in synthesis: an update. Synthesis 51, 1892–1912 (2019).

    CAS  Google Scholar 

  11. Young, A. J. & White, M. C. Catalytic Intermolecular allylic C–H alkylation. J. Am. Chem. Soc. 130, 14090–14091 (2008).

    CAS  PubMed  Google Scholar 

  12. Lin, S., Song, C., Cai, G., Wang, W. & Shi, Z. Intra/intermolecular direct allylic alkylation via Pd(ii)-catalyzed allylic C–H activation. J. Am. Chem. Soc. 130, 12901–12903 (2008).

    CAS  PubMed  Google Scholar 

  13. Bäckvall, J. E. Palladium in some selective oxidation reactions. Acc. Chem. Res. 16, 335–342 (1983).

    Google Scholar 

  14. Patel, B. A., Dickerson, J. E. & Heck, R. F. Palladium-catalyzed arylation of conjugated dienes. J. Org. Chem. 43, 5018–5020 (1978).

    CAS  Google Scholar 

  15. Wu, X. & Gong, L.-Z. Palladium(0)-catalyzed difunctionalization of 1,3-dienes: from racemic to enantioselective. Synthesis 51, 122–134 (2019).

    CAS  Google Scholar 

  16. Liao, L., Jana, R., Urkalan, K. B. & Sigman, M. S. A palladium-catalyzed three-component cross-coupling of conjugated dienes or terminal alkenes with vinyl triflates and boronic acids. J. Am. Chem. Soc. 133, 5784–5787 (2011).

    CAS  PubMed  PubMed Central  Google Scholar 

  17. Wu, X. et al. Enantioselective 1,2-difunctionalization of dienes enabled by chiral palladium complex-catalyzed cascade arylation/allylic alkylation reaction. J. Am. Chem. Soc. 137, 13476–13479 (2015).

    CAS  PubMed  Google Scholar 

  18. Frisch, A. C. & Beller, M. Catalysts for cross-coupling reactions with non-activated alkyl halides. Angew. Chem. Int. Ed. 44, 674–688 (2005).

    CAS  Google Scholar 

  19. Prier, C. K., Rankic, D. A. & MacMillan, D. W. C. Visible light photoredox catalysis with transition metal complexes: applications in organic synthesis. Chem. Rev. 113, 5322–5363 (2013).

    CAS  PubMed  PubMed Central  Google Scholar 

  20. Yoon, T. P., Ischay, M. A. & Du, J. Visible light photocatalysis as a greener approach to photochemical synthesis. Nat. Chem. 2, 527–532 (2010).

    CAS  PubMed  Google Scholar 

  21. Kärkäs, M. D., Porco, J. A. & Stephenson, C. R. J. Photochemical approaches to complex chemotypes: applications in natural product synthesis. Chem. Rev. 116, 9683–9747 (2016).

    PubMed  PubMed Central  Google Scholar 

  22. Chuentragool, P., Kurandina, D. & Gevorgyan, V. Catalysis with palladium complexes photoexcited by visible light. Angew. Chem. Int. Ed. 58, 11586–11598 (2019).

    CAS  Google Scholar 

  23. Okada, K., Okamoto, K., Morita, N., Okubo, K. & Oda, M. Photosensitized decarboxylative Michael addition through N-(acyloxy)phthalimides via an electron-transfer mechanism. J. Am. Chem. Soc. 113, 9401–9402 (1991).

    CAS  Google Scholar 

  24. Qin, T. et al. A general alkyl–alkyl cross-coupling enabled by redox-active esters and alkylzinc reagents. Science 352, 801–805 (2016).

    CAS  PubMed  PubMed Central  Google Scholar 

  25. Fawcett, A. et al. Photoinduced decarboxylative borylation of carboxylic acids. Science 357, 283–286 (2017).

    CAS  PubMed  Google Scholar 

  26. Huihui, K. M. M. et al. Decarboxylative cross-electrophile coupling of N-hydroxyphthalimide esters with aryl iodides. J. Am. Chem. Soc. 138, 5016–5019 (2016).

    CAS  PubMed  PubMed Central  Google Scholar 

  27. Proctor, R. S. J., Davis, H. J. & Phipps, R. J. Catalytic enantioselective Minisci-type addition to heteroarenes. Science 360, 419–422 (2018).

    CAS  PubMed  Google Scholar 

  28. Ma, J. et al. Synthesis of β-substituted γ-aminobutyric acid derivatives through enantioselective photoredox catalysis. Angew. Chem. Int. Ed. 57, 11193–11197 (2018).

    CAS  Google Scholar 

  29. Schnermann, M. J. & Overman, L. E. A concise synthesis of (−)-aplyviolene facilitated by a strategic tertiary radical conjugate addition. Angew. Chem. Int. Ed. 51, 9576–9580 (2012).

    CAS  Google Scholar 

  30. Mao, R., Frey, A., Balon, J. & Hu, X. Decarboxylative C(sp 3)–N cross-coupling via synergetic photoredox and copper catalysis. Nat. Catal. 1, 120–126 (2018).

    CAS  Google Scholar 

  31. Edwards, J. T. et al. Decarboxylative alkenylation. Nature 545, 213–218 (2017).

    CAS  PubMed  PubMed Central  Google Scholar 

  32. Fu, M.-C., Shang, R., Zhao, B., Wang, B. & Fu, Y. Photocatalytic decarboxylative alkylations mediated by triphenylphosphine and sodium iodide. Science 363, 1429–1434 (2019).

    CAS  PubMed  Google Scholar 

  33. Wang, G.-Z., Shang, R. & Fu, Y. Irradiation-induced palladium-catalyzed decarboxylative Heck reaction of aliphatic N-(acyloxy)phthalimides at room temperature. Org. Lett. 20, 888–891 (2018).

    CAS  PubMed  Google Scholar 

  34. Cheng, W.-M., Shang, R. & Fu, Y. Irradiation-induced palladium-catalyzed decarboxylative desaturation enabled by a dual ligand system. Nat. Commun. 9, 5215 (2018).

    PubMed  PubMed Central  Google Scholar 

  35. Koy, M. et al. Palladium‐catalyzed decarboxylative Heck‐type coupling of activated aliphatic carboxylic acids enabled by visible light. Chem. Eur. J. 24, 4552–4555 (2018).

    CAS  PubMed  Google Scholar 

  36. Zhao, W., Wurz, R. P., Peters, J. C. & Fu, G. C. Photoinduced, copper-catalyzed decarboxylative C–N coupling to generate protected amines: an alternative to the Curtius rearrangement. J. Am. Chem. Soc. 139, 12153–12156 (2017).

    CAS  PubMed  PubMed Central  Google Scholar 

  37. Monos, T. M., McAtee, R. C. & Stephenson, C. R. J. Arylsulfonylacetamides as bifunctional reagents for alkene aminoarylation. Science 361, 1369–1373 (2018).

    CAS  PubMed  Google Scholar 

  38. Pitzer, L., Schäfers, F. & Glorius, F. Rapid assessment of the reaction-condition-based sensitivity of chemical transformations. Angew. Chem. Int. Ed. 58, 8572–8576 (2019).

    CAS  Google Scholar 

  39. Banerjee, D., Junge, K. & Beller, M. Palladium-catalysed regioselective hydroamination of 1,3-dienes: synthesis of allylic amines. Org. Chem. Front. 1, 368–372 (2014).

    CAS  Google Scholar 

  40. Plesniak, M. P., Huang, H.-M. & Procter, D. J. Radical cascade reactions triggered by single electron transfer. Nat. Rev. Chem. 1, 0077 (2017).

    Google Scholar 

  41. Sun, X., Chen, J. & Ritter, T. Catalytic dehydrogenative decarboxyolefination of carboxylic acids. Nat. Chem. 10, 1229–1233 (2018).

    CAS  PubMed  Google Scholar 

  42. Parasram, M., Chuentragool, P., Sarkar, D. & Gevorgyan, V. Photoinduced formation of hybrid aryl Pd-radical species capable of 1,5-HAT: selective catalytic oxidation of silyl ethers into silyl enol ethers. J. Am. Chem. Soc. 138, 6340–6343 (2016).

    CAS  PubMed  PubMed Central  Google Scholar 

  43. Kurandina, D., Parasram, M. & Gevorgyan, V. Visible light-induced room-temperature Heck reaction of functionalized alkyl halides with vinyl arenes/heteroarenes. Angew. Chem. Int. Ed. 56, 14212–14216 (2017).

    CAS  Google Scholar 

  44. Parasram, M., Chuentragool, P., Wang, Y., Shi, Y. & Gevorgyan, V. General, auxiliary-enabled photoinduced Pd-catalyzed remote desaturation of aliphatic alcohols. J. Am. Chem. Soc. 139, 14857–14860 (2017).

    CAS  PubMed  PubMed Central  Google Scholar 

  45. Kurandina, D., Rivas, M., Radzhabov, M. & Gevorgyan, V. Heck reaction of electronically diverse tertiary alkyl halides. Org. Lett. 20, 357–360 (2018).

    CAS  PubMed  PubMed Central  Google Scholar 

  46. Chuentragool, P. et al. Aliphatic radical relay Heck reaction at unactivated C(sp 3)–H sites of alcohols. Angew. Chem. Int. Ed. 58, 1794–1798 (2019).

    CAS  Google Scholar 

  47. Ratushnyy, M., Parasram, M., Wang, Y. & Gevorgyan, V. Palladium-catalyzed atom-transfer radical cyclization at remote unactivated C(sp 3)−H sites: hydrogen-atom transfer of hybrid vinyl palladium radical intermediates. Angew. Chem. Int. Ed. 57, 2712–2715 (2018).

    CAS  Google Scholar 

  48. Chuentragool, P., Parasram, M., Shi, Y. & Gevorgyan, V. General, mild, and selective method for desaturation of aliphatic amines. J. Am. Chem. Soc. 140, 2465–2468 (2018).

    CAS  PubMed  PubMed Central  Google Scholar 

  49. Wang, G. Z., Shang, R., Cheng, W. M. & Fu, Y. Irradiation-induced Heck reaction of unactivated alkyl halides at room temperature. J. Am. Chem. Soc. 139, 18307–18312 (2017).

    CAS  PubMed  Google Scholar 

  50. Xing, W., Shang, R., Wang, G.-Z. & Fu, Y. Visible light-induced palladium-catalyzed ring opening β-H elimination and addition of cyclobutanone oxime esters. Chem. Commun. 55, 14291–14294 (2019).

    CAS  Google Scholar 

  51. Zhou, W. J. et al. Visible-light-driven palladium-catalyzed radical alkylation of C–H bonds with unactivated alkyl bromides. Angew. Chem. Int. Ed. 56, 15683–15687 (2017).

    CAS  Google Scholar 

  52. Kancherla, R. et al. Oxidative addition to palladium(0) made easy through photoexcited-state metal catalysis: experiment and computation. Angew. Chem. Int. Ed. 58, 3412–3416 (2019).

    CAS  Google Scholar 

  53. McMahon, C. M. & Alexanian, E. J. Palladium-catalyzed Heck-type cross-couplings of unactivated alkyl iodides. Angew. Chem. Int. Ed. 53, 5974–5977 (2014).

    CAS  Google Scholar 

  54. Zou, Y. & Zhou, J. Palladium-catalyzed intermolecular Heck reaction of alkyl halides. Chem. Commun. 50, 3725–3728 (2014).

    CAS  Google Scholar 

  55. Citterio, A., Arnoldi, A. & Minisci, F. Nucleophilic character of alkyl radicals. 18. Absolute rate constants for the addition of primary alkyl radicals to conjugated olefins and 1,4-benzoquinone. J. Org. Chem. 44, 2674–2682 (1979).

    CAS  Google Scholar 

  56. Benn, R. et al. Intermediates in the palladium-catalyzed reactions of 1,3-dienes. 2. Preparation and structure of (η13-octadienediyl)palladium complexes.Organometallics 4, 1945–1953 (1985).

    CAS  Google Scholar 

  57. Jackstell, R., Grotevendt, A., Andreu, M. G. & Beller, M. A practical palladium-catalyzed telomerization for the synthesis of functionalized alcohols. Org. Proc. Res. Dev. 13, 349–353 (2009).

    CAS  Google Scholar 

  58. Trost, B. M. & Metzner, P. J. Reaction of olefins with palladium trifluoroacetate. J. Am. Chem. Soc. 102, 3572–3577 (1980).

    CAS  Google Scholar 

  59. Liu, G., Yin, G. & Wu, L. Palladium-catalyzed intermolecular aerobic oxidative amination of terminal alkenes: efficient synthesis of linear allylamine derivatives. Angew. Chem. Int. Ed. 47, 4733–4736 (2008).

    CAS  Google Scholar 

  60. Reed, S. A. & White, M. C. Catalytic intermolecular linear allylic C–H amination via heterobimetallic catalysis. J. Am. Chem. Soc. 130, 3316–3318 (2008).

    CAS  PubMed  PubMed Central  Google Scholar 

Download references

Acknowledgements

This work was generously supported by the Alexander von Humboldt Foundation (H.-M.H.), the European Union’s Horizon 2020 research and innovation programme, under Marie Skłodowska-Curie grant agreement number 843349-H2020-MSCA-IF-2018 (E.S.), and the Deutsche Forschungsgemeinschaft (SFB 858; Leibniz Award). We thank S. Klabunde for assistance with the EPR studies, B. Heidrich and U. Rodehorst for assistance with the X-ray photoelectron spectroscopy studies, K. Bergander for the NMR measurements and C. G. Daniliuc for the X-ray crystallographic analysis. We also thank M. van Gemmeren, F. Strieth-Kalthoff, F. Sandfort, M. J. James, T. Dalton, J. Ma, Z. Nairoukh, J.-H. Ye, T. Patra, C. Chen, Q. Sun, J. Li and M. Freitag (all at the University of Münster) for helpful discussions.

Author information

Authors and Affiliations

Authors

Contributions

H.-M.H. and F.G. directed the project. H.-M.H., M.K., E.S., J.L.S. and F.G. designed the experiments. H.-M.H., M.K. and E.S. performed all of the experiments and analysed all of the data. P.M.P. performed all of the computational studies. H.-M.H. and F.G. wrote the manuscript with contributions from all authors.

Corresponding author

Correspondence to Frank Glorius.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

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

Supplementary information

Supplementary Information

Supplementary methods, Figs. 1–13, Tables 1–5 and references.

Supplementary Data 1

Calculated atomic coordinates.

Compound 20

Crystallographic data for compound 20.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Huang, HM., Koy, M., Serrano, E. et al. Catalytic radical generation of π-allylpalladium complexes. Nat Catal 3, 393–400 (2020). https://doi.org/10.1038/s41929-020-0434-0

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41929-020-0434-0

This article is cited by

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