Bibliographic record
Abstract
Abstract The reactivity of metal fragments MeLi(THF), Me 2 Mg, Me 2 Zn and Me 3 Al with a variety of imine/pyridine ligands was studied by DFT methods. Ligands having at least two such groups in conjugation very effectively accept an electron from a metal–carbon bonding orbital and thus assist alkyl dissociation: the M–Me dissociation free energy Δ G d decreases by about 45 kcal/mol for the Li, Mg and Zn fragments, and by 60–70 kcal/mol for Me 3 Al. Paths for transfer of an alkyl group to the ligands were also explored. Paths for transfer to ligand carbon atoms were found to have high barriers, and such transfers are instead proposed to proceed via initial M–Me dissociation. Direct alkyl transfer to ligand nitrogen atoms is somewhat easier, and for the most electropositive metal Li such a transfer might compete with radical chemistry. For Dimpy, the most stable products are the C3 and C4 alkylation ones. However, the observed regioselectivity of alkyl transfer (often to N py or C2) does not correlate with product stability and is likely to be a complicated function of radical stability, steric factors and unpaired electron density distribution. The results illustrate that Dimpy and related ligands should be considered strong, reversible oxidants.
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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 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 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) | 0.106 | 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".