The retro-ene reaction of gaseous immonium ions revisited
- Creators
- Sølling, Theis I.
- Hammerum, Steen
Abstract
The retro-ene reaction is a common reaction of metastable immonium ions, leading to the expulsion of an alkene molecule. The kinetic energy release that accompanies this reaction decreases with alkyl substitution on the γ-carbon of the immonium ion. A number of authors have taken this result to indicate that the retro-ene reaction proceeds in a non-concerted manner via a carbocation intermediate. Using ab initio calculations to test this hypothesis we find that the retro-ene reaction is a concerted process, in which the reactant immonium ion is connected to the products via a single six-membered cyclic transition state. The calculated energy barriers and the measured kinetic energy releases are highly sensitive to alkyl substitution at the γ-position, which indicates that a substantial fraction of the positive charge of the transition state resides at the γ-carbon, not that the retro-ene reaction is a stepwise process with a carbocation intermediate.
Additional Information
© 2001 Royal Society of Chemistry. Received 19 Jun 2001, Accepted 10 Oct 2001. First published on the web 09 Nov 2001. We gratefully acknowledge Statens Naturvidenskabelige Forskningsraad and the Australian National University Supercomputing Facility for generous grants of computer timeAttached Files
Published - SOLjcspt201.pdf
Supplemental Material - b105386h.doc
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Additional details
- Eprint ID
- 27884
- Resolver ID
- CaltechAUTHORS:20111121-095541906
- Statens naturvidenskabelige Forskningsraad
- Australian National University Supercomputing Facility
- Created
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2011-11-21Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field