Reactions of Tertiary Phosphines with Alcohols in Aqueous Media
Bibliographic record
Abstract
The phosphines R<sub>2</sub>R′P [R = R′ = Me, Et, <sup><i>n</i></sup>Pr, <sup><i>i</i></sup>Pr, (CH<sub>2</sub>)<sub>3</sub>OH; Me<sub>2</sub>PhP and MePh<sub>2</sub>P] react with 2- or 4-hydroxybenzyl alcohols, including “lignin-type” vanillyl, syringyl, and α-methylvanillyl alcohols, in a 1:1 ratio in aqueous media, to give zwitterionic phosphobetaine products; these on treatment with aq HCl form the corresponding phosphonium chlorides in good to excellent yields. The syringyl derivative [3,5-(OMe)<sub>2</sub>-4-OH-C<sub>6</sub>H<sub>2</sub>CH<sub>2</sub>PEt<sub>3</sub>]Cl was structurally characterized by X-ray analysis. Kinetically, the reactivity of the benzyl alcohols, studied with the water-soluble [HO(CH<sub>2</sub>)<sub>3</sub>]<sub>3</sub>P, decreases with substituents in the order 2-hydroxy > 4-hydroxy > vanillyl > syringyl > α-methylvanillyl, while 3-hydroxybenzyl alcohol is unreactive; the trend is consistent with reactivity requiring the presence of an <i>ortho</i>- or <i>para</i>-OH substituent in the aromatic ring of the alcohol, and that the reactions proceed via a carbocation species stabilized as a quinone methide. Triethylphosphine reacts with coniferyl alcohol at the CC moiety to give a zwitterionic intermediate that is again converted by aq HCl to a phosphonium chloride; no reaction was observed with cinnamyl alcohol. The effect on a phenolic p<i>K</i><sub>a</sub> by incorporation of a phosphonium substituent is also measured.
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 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 | 0.000 | 0.001 |
| 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 | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.260 | 0.001 |
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 teacher head, 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".