Ethenesulfonyl Fluoride: The Most Perfect Michael Acceptor Ever Found?
Quan Chen1, Peter Mayer1, Herbert Mayr2
1Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstrasse 5-13, Haus F, 81377, München, Germany.
Angewandte Chemie (International Ed. in English)
|May 10, 2016
Summary
Ethenesulfonyl fluoride (ESF) is a potent Michael acceptor, exhibiting strong electrophilicity. Its reactivity was confirmed in reactions with sulfonium ylides, pyridinium ylides, and electron-rich arenes.
Area of Science:
- Organic Chemistry
- Reaction Kinetics
- Computational Chemistry
Background:
- Understanding the electrophilicity of reagents is crucial for predicting and controlling chemical reactions.
- Ethenesulfonyl fluoride (ESF) is a potentially useful reagent, but its reactivity profile requires detailed investigation.
- A comprehensive electrophilicity scale aids in comparing and selecting reagents for various synthetic applications.
Purpose of the Study:
- To determine the electrophilicity parameter of ethenesulfonyl fluoride (ESF).
- To evaluate the performance of ESF as a Michael acceptor and in electrophilic aromatic substitutions.
- To establish the position of ESF within a broader scale of electrophilicity.
Main Methods:
- Kinetic measurements of reactions between ESF and sulfonium/pyridinium ylides using photometric detection.
- Application of the correlation lg k20°C = sN (N+E) to quantify electrophilicity.
- Experimental confirmation of ESF's reactivity in uncatalyzed electrophilic aromatic substitutions with alkyl-substituted pyrroles.
Main Results:
- The electrophilicity parameter (E) for ESF was determined to be -12.09.
- ESF was identified as one of the strongest Michael acceptors on the established electrophilicity scale.
- The predicted utility of ESF in electrophilic aromatic substitutions was experimentally validated.
Conclusions:
- Ethenesulfonyl fluoride (ESF) possesses exceptionally high electrophilicity, classifying it as a powerful Michael acceptor.
- ESF demonstrates significant reactivity towards various nucleophiles, including electron-rich arenes.
- The findings support the use of ESF as a versatile reagent in organic synthesis.
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