What the study found
The study found that the α,β-unsaturated ketone derived from 9(10H)-phenanthrenone is more electrophilic, meaning more electron-accepting in a chemical reaction, than the one derived from 1-acenaphthenone. The two compounds were placed at different positions on the Mayr reactivity scale, with the phenanthrenone derivative in the reactivity range of related ortho-quinone methides and the acenaphthenone derivative similar to cyclic α,β-unsaturated lactones with an exocyclic methylene group.
Why the authors say this matters
The authors conclude that the Mayr reactivity scales can be used to systematically select further nucleophilic reaction partners for both electrophiles. The study suggests that quantifying electrophilicity can help compare related reactive compounds and place them on established reactivity scales.
What the researchers tested
The researchers examined how ring size in dibenzo-annulated ketones affects the reactivity of an exocyclic electron-deficient π-system. They monitored nucleophilic addition of carbanions, which are negatively charged carbon-based reactants, to both Michael acceptors in dimethyl sulfoxide at 20°C using UV-Vis spectroscopy, then used the measured second-order rate constants and reported reactivity parameters to calculate electrophilicity values with the Mayr–Patz equation.
What worked and what didn't
The kinetic measurements showed that the phenanthrenone-derived Michael acceptor was more electrophilic than the acenaphthenone-derived one. Quantum chemical calculations also supported this comparison, indicating less advanced bond formation in the transition state and a greater thermodynamic driving force for adduct formation for the phenanthrenone derivative. The abstract does not report any failed experiments or negative results beyond this comparison.
What to keep in mind
The summary describes only two specific electrophiles and their reactions with carbanions in dimethyl sulfoxide at 20°C, so the findings are limited to that system. The abstract does not provide broader biological, practical, or clinical limitations.
Key points
- The phenanthrenone-derived α,β-unsaturated ketone was more electrophilic than the acenaphthenone-derived compound.
- Second-order rate constants for carbanion addition were measured by UV-Vis spectroscopy in dimethyl sulfoxide at 20°C.
- Electrophilicity values were calculated with the Mayr–Patz equation using reported reactivity parameters.
- Quantum chemical calculations supported the stronger electrophilicity of the phenanthrenone derivative.
- The authors say Mayr reactivity scales can help select future nucleophilic reaction partners.
Disclosure
- Research title:
- Phenanthrenone-derived ketone is more electrophilic than acenaphthenone-derived ketone
- Authors:
- Christoph Groß, Jan Brossette, Luc Schellmann, Peter Mayer, Hendrik Zipse, Armin R. Ofial
- Institutions:
- Ludwig-Maximilians-Universität München, Ludwig-Maximilians-Universität München, Ludwig-Maximilians-Universität München, Ludwig-Maximilians-Universität München, Ludwig-Maximilians-Universität München, Ludwig-Maximilians-Universität München
- Publication date:
- 2026-01-09
- DOI:
- 10.1002/poc.70061
- OpenAlex record:
- View
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