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What defines electrophilicity in carbonyl compounds
F Matthias Bickelhaupt1,2,3, Israel Fernández4
1Department of Chemistry and Pharmaceutical Sciences, AIMMS, Vrije Universiteit Amsterdam The Netherlands f.m.bickelhaupt@vu.nl.
Chemical Science
|March 15, 2024
Summary
Electrophilicity in cyclohexanones and benzaldehydes is primarily driven by electrostatic forces, not frontier molecular orbital interactions. This finding challenges conventional understanding of chemical reactivity in these carbonyl compounds.
Area of Science:
- Organic Chemistry
- Computational Chemistry
Background:
- Electrophilicity is a key concept in organic chemistry, dictating reactivity towards nucleophiles.
- Current models often emphasize donor-acceptor frontier molecular orbital (MO) interactions to explain electrophilicity trends.
Purpose of the Study:
- To investigate the origin of electrophilicity in cyclohexanones and benzaldehydes.
- To determine the dominant factors governing the reactivity of these carbonyl compounds with nucleophiles.
Main Methods:
- Utilized the activation strain model for reactivity analysis.
- Employed quantitative Kohn-Sham molecular orbital (MO) theory for electronic structure calculations.
Main Results:
- Electrostatic attractions between the carbonyl compound and the nucleophile (cyanide) are the primary drivers of electrophilicity.
- Donor-acceptor frontier MO interactions showed minimal influence on the reactivity of the studied compounds.
Conclusions:
- The electrostatic component of the interaction is more critical than frontier MO theory for understanding electrophilicity in these systems.
- Re-evaluation of reactivity models for carbonyl compounds may be necessary based on these findings.
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