<i>P</i>,<i>P</i>′-(9,9-Dimethyl-9<i>H</i>-xanthene-4,5-diyl)bis[<i>N</i>,<i>N</i>,<i>N</i>′,<i>N</i>′-tetraethyl-phosphonous diamide]
Bibliographic record
Abstract
[349100-75-0] C31H52N4OP2 (MW 558.72) InChI = 1S/C31H52N4OP2/c1-11-32(12-2)37(33(13-3)14-4)27-23-19-21-25-29(27)36-30-26(31(25,9)10)22-20-24-28(30)38(34(15-5)16-6)35(17-7)18-8/h19-24H,11-18H2,1-10H3 InChIKey = APRIDPKHBSWSHQ-UHFFFAOYSA-N (reagent may be used to prepare other Xantphos-based ligands and as a ligand for rhodium complexes used in hydroamination reactions) Physical Data: mp 99–104 °C; 1H NMR (300 MHz, C6D6) δ 7.60 (d, J = 7.5 Hz, 2H), 7.22 (d, J = 7.5 Hz, 2H), 7.06 (t, J = 7.5 Hz, 2 H), 3.19 (m, 16H; CH2), 1.55 (s, 6H; CH3), 1.06 (t, 12H; CH3); 13C NMR (75 MHz, C6D6) δ 151.0, 130.6, 130.1, 129.5, 126.0, 122.4, 43.3, 33.9, 32.7, 14.5; 31P NMR (121 MHz, C6D6) δ 92.3. Anal. calcd. (%) for C31H52N4OP2 (558.7): C, 66.6; H, 9.38; N, 10.0. Found: C, 65.5; H 9.26; N, 9.7.1 An X-ray crystal structure has also been described.2 Solubility: sol toluene, ether, dioxane; insol pentane, hexane. Form Supplied in: white to yellow solid; commercially available. Preparative Method: 9,9-dimethylxanthene (2.85 g, 13.56 mmol) and N,N,N′,N′-tetramethylethylenediamine (TMEDA) (3.32 g, 28.48 mmol) were dissolved in diethyl ether (50 mL). The solution was cooled to −40 °C. n-Butyllithium (11.4 mL, 2.5 M in hexane) was added to the mixture dropwise. The solution was allowed to warm up to room temperature and stirred overnight. ClP(NEt2)2 (6.0 g, 18.99 mmol) was dissolved in diethyl ether (40 mL) and added to the reaction mixture at −80 °C. The solution was allowed to warm up to room temperature and stirred overnight. The solvent was removed by evaporation, and the resulting solid was dissolved in pentane (40 mL) and filtered to remove solids. Excess TMEDA was removed by azeotropic evaporation with toluene (3 × 20 mL). Pentane (10 mL) was added to the solid, and the mixture was stored overnight at −25 °C. The crystals that had formed were separated from the solution by filtration. The crystals were dried in vacuo, yielding a pure dark yellow solid. Yield: 4.64 g, 61.3%.3 Handling, Storage, and Precautions: reasonably stable to air and moisture, but should be stored under inert atmosphere.
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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) | 0.001 | 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 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.015 | 0.006 |
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".