N-Heterocyclic phosphenium cations: syntheses and cycloaddition reactions
Bibliographic record
Abstract
A series of trifluoromethanesulfonate (OTf) salts of N-heterocyclic phospheniums (NHP) bearing phenyl (1a), para-methoxyphenyl (1b), 2,6-diisopropylphenyl (1c) and mesityl (1d) substituents is reported. The compounds are made by a modification to a literature procedure that improves the overall yields for and by 15 and 23%, respectively. Two unwanted side-products in the synthesis of , the diammonium salt, [(2,6-iPr-C6H3)N(H)2CH2CH2N(H)2(2,6-iPr-C6H3)]Cl2 (4) and the bisphosphine (2,6-iPr-C6H3)N(PCl2)CH2CH2N(PCl2)(2,6-iPr-C6H3) (5), are crystallographically characterized, as is the intermediate cyclic chlorophosphine, C1PN(4-OMe-C6H4)CH2CH2N(4-OMe-C6H4) (3b). The phenyl-substituted NHP is fully characterized, including by X-ray crystallography, for the first time; this compound contains a short P-O contact of 2.1850(14) A. Cycloaddition reactions of with 2,3-dimethyl-1,3-butadiene give the expected spirocyclic phospholeniums, 7,8-dimethyl-1,4-diaryl-1,4-diaza-5-phopshoniaspiro[4.4]non-7-ene, as their OTf salts (6a-d), while reactions with N,N'-dimesityl-1,4-diaza-1,3-butadiene give, except in the case of , which is too bulky to react, the aza analogues, 1,4-dimesityl-6,9-diaryl-1,4,6,9-tetraaza-5-phosphoniaspiro[4.4]non-2-ene (7a, 7b and 7d). The sterically congested is in thermal equilibrium with and free diazadiene, and undergoes a substitution reaction with 2,3-dimethyl-1,3-butadiene to give .
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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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 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) | 0.012 | 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; 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".