η<sup>5</sup>-Cyclopentadienyl-η<sup>3</sup>-1-phenylallylpalladium
Bibliographic record
Abstract
[105333-10-6] C14H14Pd (MW 288.68) InChI = 1S/C9H9.C5H5.Pd/c1-2-6-9-7-4-3-5-8-9;1-2-4-5-3-1;/h2-8H,1H2;1-5H; InChIKey = STDKYMKMBSTDJK-UHFFFAOYSA-N (reacts with a variety of phosphines L to reductively eliminate C14H14 and form palladium(0) compounds of the type PdL21. The latter are believed to be the catalytic species in many cross-coupling reactions, and η5-cyclopentadienyl-η3-1-phenylallylpalladium (I) is the only readily available precatalyst known to effect quantitative PdL2 formation for use in cross-coupling reactions1) Physical Data: mp 45 °C (dec.). Solubility: soluble in most types of organic solvents. Analysis of Reagent Purity: 1H NMR spectrum (600 MHz, toluene-d8): δ 2.16 (d, J 10.5 Hz, 1H), 3.36 (d, J 6.1 Hz, 1H), 3.84 (d, 9.8 Hz, 1H), 5.14 (ddd, J 6.1 Hz, 9.8 Hz, 10.5 Hz, 1H), 5.63 (s, 5H), 6.98–7.03 (m, 3H), 7.24–7.27 (m, 2H). Form Supplied in: deep purple-red crystals; commercially available. Preparative Methods:1 all steps were carried out under an atmosphere of purified argon using solvents dried by passage through activated alumina columns (Innovative Technology Solvent Purification System) and then stored over 3A molecular sieves dried under reduced pressure at 225 °C. A solution of sodium cyclopentadienide in THF (2.0 M, Aldrich) (1.45 mL, 2.90 mmol), diluted with 20 mL THF in a dropping funnel, was added dropwise to a stirred suspension of [Pd(η3-1-Ph-C3H4)Cl]22 (0.60 g, 1.16 mmol) in 20 mL THF at −78 °C. The resulting deep purple solution was stirred for 30 min, and then warmed to room temperature. The solvent was removed at room temperature under reduced pressure and the resulting solid product was extracted using three 20 mL portions of hexanes. The filtrate was reduced under reduced pressure, yielding an oily purple solid that was dissolved in ∼5 mL hexanes at room temperature. The resulting solution was cooled at −35 °C to give purple crystals that were collected by filtration. Yield: 0.565 g, 84%. Purple-red crystals can also be obtained by sublimation at 40 °C, 1 × 10−3 Torr. Handling, Storage, and Precautions: although heating during synthesis and workup can result in decomposition and palladium metal deposition, η5-cyclopentadienyl-η3-1-phenylallylpalladium (I) is, once prepared and purified, stable in solution for at least 30 min at 50 °C. Although long-term storage of I is probably best in a freezer, solutions are stable for several days under air at ambient temperatures.
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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 | 0.006 |
| Meta-epidemiology (narrow) | 0.002 | 0.002 |
| Meta-epidemiology (broad) | 0.003 | 0.002 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.003 | 0.001 |
| Research integrity | 0.002 | 0.002 |
| Insufficient payload (model declined to judge) | 0.023 | 0.002 |
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; both teacher heads agree on what is shown here.
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".