Advertisement

Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

Prebiotic formation of iminothioesters. II: Addition of thiophenols to malonic nitriles

  • 92 Accesses

  • 7 Citations

Abstract

Previous kinetic studies on the addition of aliphatic thiols to activated nitriles suggest that the formation of iminothioesters (possible prebiotic precursors of thioesters) occurs through the nucleophilic addition of thiolate to the C=N group of the activated nitrile in its acidic form:

$$R S^ {\ominus} + A - CH{_2} - C \equiv N {\overset {{H^ + }} \leftrightarrows} A - CH{_2} - \begin{array}{*{20}c} C \\ | \\ {SR} \\ \end{array} = NH$$

It seemed also that this addition occurs only when the pKA of the thiol is lower than the pKA of the activated nitrile. In order to test this hypothesis, and to generalize this mechanism, similar studies have been carried out using the same nitriles (A=CN; CHO), but with thiols having lower pKA (substituted thiophenols). The results of these studies, using p-aminothiophenol (pKA=6.85), p-chlorothiophenol (pKA=5.90) and p-nitrothiophenol (pKA=4.60), including the determination of rate and equilibrium constants, is presented.

This is a preview of subscription content, log in to check access.

References

  1. (1)

    Weber, A.L. 1981, J. Mol. Evol.18, p. 24

  2. (2)

    Weber, A.L. 1982, Biosystems 15, p. 183.

  3. (3)

    Weber, A.L. 1981, J. Mol. Evol.17, p. 103.

  4. (4)

    Weber, A.L. 1982, J. Mol. Evol.18, p. 354.

  5. (5)

    Raulin F. and Toupance G. 1976, Bull. Soc. Chim. Fr. (5–6), p. 667.

  6. (6)

    Raulin, F., Bloch, S. and Toupance G. 1977, Origins of Life 8 (3), p. 247.

  7. (7)

    Daneby, J.P. and Parameswaran, K.N. 1953, J. Chem. Engineer Data 3 (3), p. 386.

  8. (8)

    Jencks, W.P. and Soloesen, K. 1971, J. Amer. Chem. Soc. 93, p. 4433.

  9. (9)

    Ferris, J.P., Sanchez, R.A. and Orgel L.E. 1968, J. Mol. Biol. 33, p. 693.

  10. (10)

    Raulin, F., Fonsalas, F. and Wolny, M. 1984, this volume, p. 151.

Download references

Author information

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Raulin, F., Lussiana, J. Prebiotic formation of iminothioesters. II: Addition of thiophenols to malonic nitriles. Origins Life Evol Biosphere 14, 157–162 (1984). https://doi.org/10.1007/BF00933653

Download citation

Keywords

  • Organic Chemistry
  • Geochemistry
  • Nitrile
  • Acidic Form
  • Thiol