Catalysis of Ester Aminolysis by Cyclodextrins. The Reaction of Alkylamines with <i>p</i>-Nitrophenyl Alkanoates
Bibliographic record
Abstract
The effects of four cyclodextrins (alpha-CD, beta-CD, hydroxypropyl-beta-CD, and gamma-CD) on the aminolysis of p-nitrophenyl alkanoates (acetate to heptanoate) by primary amines (n-propyl to n-octyl, isobutyl, isopentyl, cyclopentyl, cyclohexyl, benzyl) in aqueous solution have been investigated. Rate constants for amine attack on the free and CD-bound esters (k(N) and k(cN)) have ratios (k(cN)/k(N)) varying from 0.08 (retardation) to 180 (catalysis). For the kinetically equivalent process of free ester reacting with CD-bound amine (k(Nc)), the ratios k(Nc)/k(N) vary from 0.2 to 28. Either way, there is evidence of catalysis in some cases and retardation in others. Changes in reactivity parameters with structure indicate more than one mode of transition state binding to the CDs. Short esters react with short alkylamines by attack of free amine on the ester bound by its aryl group, but for longer amines, free ester reacts with CD-bound amine. Reaction of long esters with long amines, which is catalyzed by beta-CD and gamma-CD, involves inclusion of the alkylamino group and possibly the ester acyl group. The larger cavity of gamma-CD may allow the inclusion of the ester aryl group, as well as the alkylamino group, in the transition state. Reaction between an ester bound to the CD by its acyl group and free amine appears not to be important.
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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 | 0.000 | 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 | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.004 | 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".