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 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 | 0.000 | 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 | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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 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".