Hydrolytic deamination reactions of amidine and nucleobase derivatives
Bibliographic record
Abstract
Abstract Amidines share the same NC─N building framework with many essential biochemical substances. In this work, we present a comparative mechanistic study on the deamination reactions of 19 amidine and nucleobase derivatives by the use of density functional theory. All the computations are performed at the B3LYP/6‐31G(d,p) level in the gas phase and with the polarizable continuum model (PCM). Mechanisms of 2‐ and 3‐step pathways including six‐ or eight‐membered ring transition states were explored. Our results show that the overall activation energies for the deamination of amidine derivatives are close to those of nucleobase derivatives of the saturated C5─C6 bond, and lower than those of nucleobase derivatives of the unsaturated C5─C6 bond, while purine derivatives have the highest activation energies among all the derivatives studied. The 3‐step mechanism gives results that are more consistent with the available experimental data than the 2‐step mechanism. Based on the results of our current and previous work, we believe that the 3‐step mechanism is the most likely mechanism for the hydrolytic deamination reactions of amidine and nucleobase 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 | 0.000 | 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) | 0.000 | 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".