Divergent Reactivity of Perfluoropentaphenylborole with Alkynes
Bibliographic record
Abstract
The reactions of perfluoropentaphenylborole ( 1 ) with the symmetrical internal alkynes RCCR (R = C 6 F 5, C 6 H 5, CH 2 CH 3 ) have been explored. For R = C 6 F 5, a slow reaction occurs via a Diels−Alder pathway established for the non-fluorinated system to give the new borane perfluoroheptaphenylborepin 2 . The new perfluoroarylborane 2 and its pyridine adduct 2-py were characterized crystallographically. In contrast, the reaction of 1 with diphenylacetylene is dominated by a reaction path in which the borole electrophilically attacks the alkyne, triggering a 1,2 phenyl migration and borole ring expansion to deliver the boracyclohexadiene 3 as the major product. Minor products in this reaction were identified as diphenyl-substituted borepins resulting from the Diels−Alder reaction channel. Finally, 3-hexyne reacts with 1 via the Diels−Alder pathway, but the kinetic products are not the expected diethyl borepins but rather one of the initial Diels−Alder adducts formed prior to ring-opening to the seven-membered borepin ring. This intermediate was fully characterized and provides concrete evidence for the pericyclic reaction sequence proposed by Eisch for the reaction of pentaphenylborole with diphenylacetylene.
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 | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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 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".