Silylium ions: from controversial beginnings to useful catalysts

Silylium ions can be very fleeting — so much so that their isolation was once considered impossible. This prevailing opinion was eventually challenged by chemists brave enough to conduct the challenging experiments that revealed silylium ions to not only be tractable but also synthetically versatile.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1.

    Walker, J. C. L., Klare, H. F. T. & Oestreich, M. Cationic silicon Lewis acids in catalysis. Nat. Rev. Chem. (2020).

    Article  Google Scholar 

  2. 2.

    Reed, C. A. The silylium ion problem, R3Si+. Bridging organic and inorganic chemistry. Acc. Chem. Res. 31, 325–332 (1998).

    CAS  Article  Google Scholar 

  3. 3.

    Corey, J. Y. Generation of a silicenium ion in solution. J. Am. Chem. Soc. 97, 3237–3238 (1975).

    CAS  Article  Google Scholar 

  4. 4.

    Corey, J. Y., Gust, D. & Mislow, K. Generation of a ferrocenylsilicenium ion. J. Organomet. Chem. 107, C7–C8 (1975).

    Article  Google Scholar 

  5. 5.

    Bickart, P., Llort, F. & Mislow, K. On the evidence for the generation of a ferrocenylsilicenium. J. Organomet. Chem. 116, C1–C2 (1976).

    CAS  Article  Google Scholar 

  6. 6.

    Riddlestone, I. M. et al. Taming the cationic beast: novel developments in the synthesis and application of weakly coordinating anions. Angew. Chem. Int. Ed. 57, 13982–14024 (2018).

    CAS  Article  Google Scholar 

  7. 7.

    Müther, K. et al. A unique transition metal-stabilized silicon cation. J. Am. Chem. Soc. 133, 12442–12444 (2011).

    Article  Google Scholar 

  8. 8.

    Olah, G. A. et al. Superacid Chemistry 2nd edn Ch. 3–4 (John Wiley & Sons, 2009).

  9. 9.

    Kim, K.-C. et al. Crystallographic evidence for a free silylium ion. Science 297, 825–827 (2002).

    CAS  Article  Google Scholar 

  10. 10.

    Lambert, J. B. et al. Crystal structure of a silyl cation with no coordination to anion and distant coordination to solvent. Science 260, 1917–1918 (1993).

    CAS  Article  Google Scholar 

  11. 11.

    Shao, B. et al. Arylation of hydrocarbons enabled by organosilicon reagents and weakly coordinating anions. Science 355, 1403–1407 (2017).

    CAS  Article  Google Scholar 

  12. 12.

    Wu, Q. et al. Characterization of hydrogen-substituted silylium ions in the condensed phase. Science 365, 168–172 (2019).

    CAS  Article  Google Scholar 

Download references

Author information



Corresponding author

Correspondence to Jay S. Siegel.

Ethics declarations

Competing interests

The author declares no competing interests.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Siegel, J.S. Silylium ions: from controversial beginnings to useful catalysts. Nat Rev Chem 4, 4–5 (2020).

Download citation

Further reading

  • Chiral Memory in Silyl-Pyridinium and Quinolinium Cations

    • Anthony Fernandes
    • , Claire Laye
    • , Suman Pramanik
    • , Dayvson Palmeira
    • , Özgen Ömür Pekel
    • , Stéphane Massip
    • , Marc Schmidtmann
    • , Thomas Müller
    • , Frédéric Robert
    •  & Yannick Landais

    Journal of the American Chemical Society (2020)