Electrophilic boron carboxylate and phosphinate complexes
Bibliographic record
Abstract
The reactions of a series of carboxylic acids with H2B(C6F5)·SMe2 are shown to afford species of the form [RC(O)OB(C6F5)]2O, (R = Tol 1, Ph 2, C6F53, Me2BrC 4, Me 5) in 87-95% yields with the concurrent reduction of the carboxylic acid to the corresponding aldehyde. A mechanism for the formation of 1-5 is proposed to proceed via a cyclic eight-membered ring species. Analogues of these species were prepared via reactions of carboxylic and phosphinic acids with HB(C6F5)2 and H2B(C6F5)·SMe2, respectively, to give [TolC(O)OB(C6F5)2]26, [(C6F5)C(O)OB(C6F5)2]27, and [Ph2P(O)OBH(C6F5)]28. These products react subsequently to give TolC(O)OBH(C6F5)(NC5H4NMe2) 9 and Ph2P(O)OBH(C6F5)(NC5H4NMe2) 10. The acyloxyborate derivatives 1-4 were shown to be inactive in mediating the direct amidation of carboxylic acids, consistent with previous observations that infer the need for a sterically congested environment about the boron centres.
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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) | 0.000 | 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 | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 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 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".