<i>trans</i>-[1,3-(2,6-Diisopropylphenyl)imidazol-2-ylidene](3-chloropyridyl)palladium(II) dichloride (PEPPSI<sup>™</sup>-IPr)
Bibliographic record
Abstract
[905459-27-0] C32H40Cl3N3Pd (MW 679.46) InChI = 1S/C27H36N2.C5H4ClN.2ClH.Pd/c1-18(2)22-11-9-12-23(19(3)4)26(22)28-15-16-29(17-28)27-24(20(5)6)13-10-14-25(27)21(7)8;6-5-2-1-3-7-4-5;;;/h9-16,18-21H,1-8H3;1-4H;2*1H;/q;;;;+2/p-2 InChIKey = NLVKLFBIRDNQHR-UHFFFAOYSA-L (precatalyst for Pd-mediated CC and C-heteroatom cross-coupling reactions) Physical Data: mp 230 °C (with decomposition). Solubility: soluble in most organic solvents except for aliphatic hydrocarbons (e.g., pentane or hexanes); insoluble in water. Form Supplied in: pale beige to yellow powder or yellow crystals. Available from Sigma–Aldrich. Analysis of Reagent Purity: NMR spectroscopy. Preparative Methods: heating PdCl2 (1.0 mmol), N,N-(2,6-diisopropylphenyl)imidazolium chloride (1; IPr·HCl; 1.1 mmol), and powdered K2CO3 (5.0 mmol) at 80 °C in neat 3-chloropyridine (2 mL) with vigorous stirring for 18 h (eq 1) afforded PEPPSI™-IPr (2; 97%) as a beige powder following silica gel column filtration (CH2Cl2), vacuum distillation of excess 3-chloropyridine, and trituration with pentane.3 Purification: precipitation with pentane out of concentrated ether or CH2Cl2 solution or flash chromatography on silica gel (pentane: CH2Cl2 = 1:2). Handling, Storage, and Precautions: stable under ambient conditions in solid form or in solution. Heating at 120 °C in DMSO-d6 over 24 h results in no decomposition (1H and 13C NMR spectroscopy). Incompatible with strong acids, bases, oxidizing, and reducing agents.
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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 | 0.003 |
| Meta-epidemiology (narrow) | 0.003 | 0.003 |
| Meta-epidemiology (broad) | 0.004 | 0.002 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.004 | 0.001 |
| Research integrity | 0.004 | 0.002 |
| Insufficient payload (model declined to judge) | 0.050 | 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; 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".