Borinic Acid,<i>B</i>,<i>B</i>-Bis(2,3,4,5,6-pentafluorophenyl)-
Bibliographic record
Abstract
[2118-02-7] C12HBF10O (MW 361.93) InChI = 1S/C12HBF10O/c14-3-1(4(15)8(19)11(22)7(3)18)13(24)2-5(16)9(20)12(23)10(21)6(2)17/h24H InChIKey = MQXCDPDLPMAEIE-UHFFFAOYSA-N (mild Lewis acid catalyst; Mukaiyama aldol reactions; dehydrations of β-hydroxy ketones; Oppenauer oxidations) Physical Data: white microcrystalline solid, mp 102 °C. Solubility: sol many organic solvents. Preparative Methods: controlled hydrolysis of (C6F5)2BCl.1 The chloroborane (C6F5)2BCl is synthesized from freshly prepared (C6F5)2SnMe2 and BCl3; aqueous acidic work-up yields the borinic acid.2 (C6F5)2SnMe2 can be generated either from the Grignard reagent C6F5MgBr and Me2SnBr2 or from the organolithium reagent C6F5Li and Me2SnCl2.3 The advantages offered by the latter method include the use of a less expensive dichloro tin precursor and the generation of (C6F5)2SnMe2 with greater purity and higher yield; however, the reaction temperature must be carefully controlled during the generation of C6F5Li to avoid the highly exothermic decomposition of this species to tetrafluorobenzyne. The corresponding bromoborane (C6F5)2BBr may be prepared from C6F5HgBr and BBr3.4 Another variant involves the reaction of BCl3 with n-propanol to generate Cl2BOnPr, which when treated with 2 equiv of C6F5MgBr gives (C6F5)2BOnPr; aqueous acidic work-up yields the borinic acid.5 Bis(pentafluorophenyl)borinic acid may also be prepared by treatment of (C6F5)2BH with water, although (C6F5)BOB(C6F5)2 may be formed as a by-product since the borinic acid reacts readily with (C6F5)2BH.6 Alternatively, heating B(C6F5)3 in the presence of water at 80 °C results in the elimination of C6F5H to yield clean borinic acid.7 The latter method is noteworthy from the standpoint of operational simplicity (the borane is a commercially available reagent that exists as a solid at room temperature). Borinic esters derived from (C6F5)2BOH have also been synthesized. Generation of a strong BO bond drives the formation of borinic esters from (C6F5)2BH alcohols, epoxides, THF, or carbonyls,7 or from the combination of a carbodiimide and CO2.8 The reaction of (C6F5)2BCl with pentafluorophenol results in clean formation of the borinic ester (C6F5)2BOC6F5,9 which has been shown to act as a component of a “frustrated Lewis pair” with tri-tert-butylphosphine in the activation of nitrous oxide.10 The bis(pentafluorophenyl)borinic acid quinolyl ester (C6F5)2BQ (where Q is 8-quinolinate) can be synthesized from B(C6F5)3 and 8-hydroxyquinoline to form the zwitterionic complex (C6F5)3BQH, which, upon refluxing in benzene, loses C6F5H to form the boron quinolinate.11 Alternatively, (C6F5)2BQ can be generated from (C6F5)2BCl and 8-hydroxyquinoline. Purification: sublimation (90 °C/0.05mm). Handling, Storage, and Precautions: in general, diarylborinic acids are susceptible to oxidation upon storage under ambient conditions, yielding products at the boronic acid oxidation state. Tetracoordinate borinic esters of ethanolamine, 8-hydroxyquinoline, and related N,O ligands show improved stability toward storage in comparison to the borinic acids themselves. Bis(pentafluorophenyl)borinic acid is reported to be relatively air stable in contrast to the more electron-rich diarylborinic acids. It is not stable in neutral aqueous solution, giving pentafluorobenzene and boric acid.1
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 | 0.001 | 0.000 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.007 | 0.004 |
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".