Nitroxyl Radical Addition to Pentafulvenones Forming Cyclopentadienyl Radicals: A Test for Cyclopentadienyl Radical Destabilization
Bibliographic record
Abstract
Photochemical Wolff rearrangements in alkane solvents of the 6-diazo-2,4-cyclohexadienones 4 and 13-15 give pentafulvenone (1), 2,3-benzopentafulvenone (2), dibenzopentafulvenone (3), and 2,4-di-tert-butylpentafulvenone (16), as identified by conventional UV and IR spectroscopy. Reactions of these fulvenyl ketenes with tetramethylpiperidinyloxyl (TEMPO) proceed by addition of TEMPO to the carbonyl carbon forming delocalized radicals for 1 and 2 which add one or more further TEMPO molecules, while the initial radical products formed from 3 and 16 dimerize. The rate constants of these reactions compared to hydration rate constants for the same compounds show the benzannulated derivatives 2 and 3 fit a previous correlation k(2)(TEMPO) vs k((H(2)O), whereas for 1 and 16 there is evidence for inhibition of reactions with radicals. The deviations are consistent with an absence of aromatic stabilization of the cyclopentadienyl radicals from 1 and 16 that is compensated in the benzannulated derivatives.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.015 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".