Ruthenium(II) Diphosphine/Diamine/Diimine Complexes and Catalyzed Hydrogen-Transfer to Ketones
Bibliographic record
Abstract
An in situ product, presumed to be RuCl 2 (DPPF)(PPh 3 ), formed in CH 2 Cl 2 from a 1:1 mixture of 1,1‘-bis(diphenylphosphino)ferrocene (DPPF) and RuCl 2 (PPh 3 ) 3, reacts with 1 equiv of a diamine or a diimine (N−N donors) dissolved in MeOH to generate RuCl 2 (DPPF)(N−N) complexes: N−N is ethylenediamine (en), N, N ‘-dimethyl(ethylenediamine) (dimen), 1,3-diaminopropane (diap), 2,2‘-bipyridine (bipy), 1,10-phenanthroline (phen), and 1 S, 2 S -diaminocyclohexane (1 S,2 S -dach). Diethylenetriamine (dien), a tridentate N-donor, generates a monochloro cationic complex. The isolated complexes are trans -RuCl 2 (DPPF)(en) ( 1 ), trans -RuCl 2 (DPPF)(dimen) ( 2 ), [RuCl(DPPF)(dien)]Cl ( 3 ), trans -RuCl 2 (DPPF)(diap) ( 4 ), cis -RuCl 2 (DPPF)(bipy) ( 5 ), cis -RuCl 2 (DPPF)(phen) ( 6 ), and trans -RuCl 2 (DPPF)(1 S,2 S -dach) ( 7 ). The known complex trans -RuCl 2 (DPPB)(en) ( 8 ) was similarly made using RuCl(DPPB) 2 (μ-Cl) 3 as precursor, where DPPB is 1,4-bis(diphenylphosphino)butane. Complexes 1, 2, 5, and 8 were characterized crystallographically. Complexes 1 − 8 are effective precursor catalysts in basic 2-propanol solutions for the hydrogen-transfer hydrogenation of acetophenone; the chiral phosphine system ( 7 ) gives only ∼12% ee at high conversions to 1-phenylethanol, while at 25% conversion the ee reaches 36%. Greater activity for precursor catalyst 1 versus that of 2 qualitatively supports the “metal−ligand bifunctional” mechanism for such diphosphine/diamine systems; however, the “NH-free” diimine bipy and phen systems are as active at 80 °C as the diamine systems and must operate by a different mechanism. Complex 8 is also an effective precursor hydrogen-transfer catalyst for other alkyl−aryl and dialkyl ketones, which were used as model substrates for components of lignin; a substituted styrene was not hydrogenated.
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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 | 0.001 |
| 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) | 0.002 | 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".