Aminoxyl radical addition to arylketenes
Bibliographic record
Abstract
Abstract Kinetic studies of the addition of the aminoxyl radical TEMPO (2,2,6,6‐tetramethylpiperidinylaminoxyl, TO·) to the 4‐substituted phenylketenes 8 (4‐RC6H4CHCO, R = NO2, CN, Cl, H, CH3, CH3O) and to 3‐pyridylketene (15) reveal a correlation of logk2(TEMPO) with the Hammett sigma parameters of the substituents (including the aza substituent of 15), with rho = 1.58 (r = 0.94). A better correlation is obtained with the rate constants for hydration of the same substrates: logk2(TEMPO) = 1.64logk(H2O)−5.76 (r = 0.98). These results fit within a previously established correlation of ketene hydration reactivity with aminoxyl radical reactivity, and confirm that the reactivity of TEMPO in additions to ketenes is dominated by the nucleophilic character of the aminoxyl oxygen, with a strong trend of increasing reactivity for more electrophilic ketenes. Copyright © 2006 John Wiley & Sons, Ltd.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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 source (direct Gemma or distilled Codex), 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".