Use of the Imine–Enamine Equilibrium in Cooperative Ligand Design
Bibliographic record
Abstract
The imine–phosphine ligands Ph 2 PC 5 H 7 NAr, where Ar = 2,6-Pr i 2 C 6 H 3, 2,6-Me 2 C 6 H 3, were deprotonated using KH to generate the corresponding potassium salts, which were reacted with [(COD)IrCl] 2 to generate the enamidophosphine derivatives (COD)Ir(Ph 2 PC 5 H 6 NAr) (Ar = 2,6-Pr i 2 C 6 H 3, 4a; Ar = 2,6-Me 2 C 6 H 3, 4b ). These complexes were exposed to alcohols, H 2, and CO to generate a series of products, some of which involve protonation of the enamido unit to generate the imine tautomer. The reaction of 4a with isopropyl alcohol or H 2 generates the dinuclear hexahydride [(Ph 2 PC 5 H 7 N-2,6-Pr i 2 C 6 H 3 )IrH 2 ] 2 (μ-H) 2 ( 5a ), while the reaction with primary alcohols generates the dicarbonyl enamidophosphine complex (CO) 2 Ir(Ph 2 PC 5 H 6 NAr) ( 6a ). The reaction of the hexahydride 5a with CO generates 6a, for which a mechanism is proposed on the basis of monitoring this reaction as a function of time by NMR spectroscopy. On the basis of these experiments, cooperative ligand effects can be replicated by imine–phosphine ligands by proton transfer to and from the ligand backbone.
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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 | 0.001 | 0.001 |
| 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 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 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".