Jump to main content
Jump to site search

Issue 25, 2018
Previous Article Next Article

Thermodynamic versus kinetic control in substituent redistribution reactions of silylium ions steered by the counteranion

Author affiliations

Abstract

An in-depth experimental and theoretical study of the substituent exchange reaction of silylium ions is presented. Apart from the substitution pattern at the silicon atom, the selectivity of this process is predominantly influenced by the counteranion, which is introduced with the trityl salt in the silylium ion generation. In contrast to Müller's protocol for the synthesis of triarylsilylium ions under kinetic control, the use of Reed's carborane anions leads to contact ion pairs, allowing selective formation of trialkylsilylium ions under thermodynamic control. DFT calculations finally revealed an unexpected mechanism for the rate-determining alkyl exchange step, which is initiated by an unusual 1,2-silyl migration in the intermediate ipso-disilylated arenium ion. The resulting ortho-disilylated arenium ion can then undergo an alkyl transfer via a low-barrier five-centered transition state.

Graphical abstract: Thermodynamic versus kinetic control in substituent redistribution reactions of silylium ions steered by the counteranion

Back to tab navigation

Supplementary files

Publication details

The article was received on 22 Apr 2018, accepted on 20 May 2018 and first published on 21 May 2018


Article type: Edge Article
DOI: 10.1039/C8SC01833B
Citation: Chem. Sci., 2018,9, 5600-5607
  • Open access: Creative Commons BY license
  •   Request permissions

    Thermodynamic versus kinetic control in substituent redistribution reactions of silylium ions steered by the counteranion

    L. Omann, B. Pudasaini, E. Irran, H. F. T. Klare, M. Baik and M. Oestreich, Chem. Sci., 2018, 9, 5600
    DOI: 10.1039/C8SC01833B

    This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. Material from this article can be used in other publications provided that the correct acknowledgement is given with the reproduced material.

    Reproduced material should be attributed as follows:

    • For reproduction of material from NJC:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the Centre National de la Recherche Scientifique (CNRS) and the RSC.
    • For reproduction of material from PCCP:
      [Original citation] - Published by the PCCP Owner Societies.
    • For reproduction of material from PPS:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the European Society for Photobiology, the European Photochemistry Association, and RSC.
    • For reproduction of material from all other RSC journals:
      [Original citation] - Published by The Royal Society of Chemistry.

    Information about reproducing material from RSC articles with different licences is available on our Permission Requests page.

Search articles by author

Spotlight

Advertisements