Bifunctional Activation of NHC‐Zinc Pre‐Catalyst for Effective Hydroboration of Quinolines and Nitriles
Bibliographic record
Abstract
Abstract Zinc dihydride complexes supported by bulky N‐heterocyclic carbenes (NHC) are efficient catalysts in hydroboration reactions. Herein, a set of zinc complexes with an amino‐pyrrolide chelate (H L 1 ) and the small NHC ligand, 2,3‐dimethyl‐3,4‐dichloroimidazol‐2‐ylidene (DDI) was synthesized and characterized. In particular, Zn(H L 1 ) 2 (DDI) ( Zn4) displayed high activity in catalytic nitrile dihydroboration using 0.01 mol % loading, and quinoline hydroboration using 0.05 mol % loading at room temperature. Stoichiometric reaction of Zn4 with 4 equiv. of pinacolborane (HBpin) produced ZnH 2 (DDI) ( Zn5 ) and 2 equiv. of dissociated (Bpin) 2 L 1 . Complex Zn5 , generated in situ by this bifunctional catalyst activation step, was shown to be more active than the bis‐NHC analog ZnH 2 (DDI) 2 and previously reported examples with bulky NHC ligands. In addition, variable time normalization analysis (VTNA) showed first‐order dependence on [quinoline], [HBpin] and [ Zn4 ], revealing that a single Zn−H is involved in the catalytic cycle, as was also observed in the stoichiometric reaction of Zn5 with quinoline. VTNA also indicated that this catalyst faces neither deactivation nor product inhibition.
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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".