Tandem C–F and C–H Bond Activation in Fluoroolefins Promoted by a Bis(diethylphosphino)methane-Bridged Diiridium Complex: Role of Water in the Activation Processes
Bibliographic record
Abstract
The diiridium complex [Ir 2 (CO) 3 (μ-H)(depm) 2 ] + ( 1 ) reacts with vinyl fluoride, 1,1-difluoroethylene, trifluoroethylene, and tetrafluoroethylene, undergoing C–F bond activation in all cases, in addition to C–H activation in the incompletely substituted fluoroolefins. Reaction of 1 with vinyl fluoride readily undergoes geminal C–F/C–H activation, resulting in the bridging vinylidene product, [Ir 2 (H)(CO) 3 (μ-C═CH 2 )(depm) 2 ] + ( 2 ). Compound 1 reacts with 1,1-difluoroethylene at subambient temperature to give minor amounts of [Ir 2 (CO) 3 (κ 1:η 2 -C≡CH)(depm) 2 ] + ( 4 ), resulting from the loss of 2 equiv of HF from the fluoroolefin complex, along with a mixture of two isomers of [Ir 2 (C(F)═CH 2 )(CO) 3 (μ-CF 2 CH 2 )(depm) 2 ] + ( 5a / 5b ), in which 2 equiv of the olefin has been incorporated. Compound 1 also reacts with trifluoroethylene at −30 °C, giving a 1:1 mix of isomers of the trifluoroethylene-bridged species [Ir 2 (H)(CO) 3 (μ-CFHCF 2 )(depm) 2 ] + ( 7a / 7b ), and warming this mixture above −15 °C converts both isomers to two products, [Ir 2 (H)(CO) 3 (μ-C═CF 2 )(depm) 2 ] + ( 8 ), in which the geminal C–F and C–H bonds in the fluoroolefin have been activated, and [Ir 2 (H)(CO) 3 (μ-CHCF 3 )(depm) 2 ] + ( 9 ), the result of a [1,2]-fluoride shift to give the bridging 2,2,2-trifluoroethylidene moiety. Compound 9 reacts further with a second equivalent of trifluoroethylene over 12 h to produce the 2,2,2-trifluoroethylidene/ cis -difluorovinyl complex, [Ir 2 (C(F)═CFH)(CO) 3 (μ-CHCF 3 )(depm) 2 ] + ( 10 ). Finally, tetrafluoroethylene reacts with 1 to produce the bridged adduct, [Ir 2 (H)(CO) 3 (μ-CF 2 CF 2 )(depm) 2 ] + ( 11 ), followed by a single C–F activation to give [Ir 2 (C(F)═CF 2 )(CO) 3 (depm) 2 ] + ( 12 ). The roles of the hydride ligand and exogenous water in the C–F activation processes are discussed.
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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 | 0.000 | 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".