Bibliographic record
Abstract
[1660-43-7] C15H17BF4S (MW 316.20) InChI = 1S/C15H17S.BF4/c1-13(2)16(14-9-5-3-6-10-14)15-11-7-4-8-12-15;2-1(3,4)5/h3-13H,1-2H3;/q+1;-1 InChIKey = OYVGOJMOYZVZFZ-UHFFFAOYSA-N (transformation of carbonyls to gem-dimethyloxiranes;2 conversion of α,β-unsaturated systems3 and diene esters4 to geminal substituted cyclopropanes) Preparative Method: this reagent is not commercially available and must be made prior to use. The ylide isopropylidenediphenylsulfurane, obtained by deprotonation with an appropriate base, is usually formed in situ and used immediately because of its extremely low stability.2 Two methods have been reported for the preparation of the sulfurane. Ethyldiphenylsulfonium tetrafluoroborate (formed by the reaction of diphenyl sulfide with triethyloxonium tetrafluoroborate, eq 1) is suspended in a solution of DME. The ylide is formed by addition of LiCHCl2 at −70 °C and reacted with MeI (1.1 equiv). The desired sulfonium salt precipitates from solution. The isopropylidenediphenylsulfurane is formed by addition of LDA to this suspension at −78 °C (eq 2).2 (1) (2) A second, but less efficient, method of preparation involves the reaction of diphenyl sulfide, AgBF4, and neat isopropyl iodide (eq 3).2 (3) Three different base/solvent systems have been used to generate the isopropylidenediphenylsulfurane ylide: DME/LiCHCl2, t-BuOK/THF,5 and PhLi/THF.6 All methods have proven equally efficient. Different diastereomer ratios have been obtained with the t-BuOK/THF method compared to the other systems.7
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.014 | 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".