Coordination and Activation of Diazoalkanes in the Presence of Rh/Ru and Rh/Os Metal Combinations
Bibliographic record
Abstract
The substituted diazoalkanes—ethyl diazoacetate (EDA), diethyl diazomalonate (DEDM), and trimethylsilyl diazomethane (TMSDM)—react readily with the methylene-bridged tricarbonyl species [RhM(CO) 3 (μ-CH 2 )(dppm) 2 ][CF 3 SO 3 ] (M = Os ( 5 ), Ru ( 6 ); dppm = μ-Ph 2 PCH 2 PPh 2 ) to produce the corresponding substituted olefin (through loss of N 2 and subsequent coupling of the diazoalkane-generated alkylidene fragment and the methylene unit), the known tetracarbonyl species [RhM(CO) 4 (dppm) 2 ][CF 3 SO 3 ] (M = Os ( 1 ), Ru ( 2 )), and uncharacterized decomposition products. In the reaction of 5 with EDA at −20 °C the intermediate olefin adduct, [RhOs(CO) 3 (η 2 -CH 2 -CHR)(dppm) 2 ][CF 3 SO 3 ] ( 7; R = CO 2 Et) is observed, which decomposes with release of the olefin upon warming. The methylene-bridged tetracarbonyl species [RhM(CO) 4 (μ-CH 2 )(dppm) 2 ][CF 3 SO 3 ] (M = Os( 3 ), Ru ( 4 )) also react with these diazoalkanes to yield the same products, only at a much slower rate. Attempts to generate the alkylidene-bridged products, analogous to 3 and 4, by reaction of 1 or 2 with EDA, DEDM, and TMSDM accompanied by loss of N 2 instead gave complexes containing the diazoalkane unit. In the reaction with EDA condensation of this unit with a carbonyl ligand occurs accompanied by migration of the diazoalkane hydrogen to the carbonyl oxygen, yielding [RhM(CO) 3 (μ-η 1:η 1 -N 2 C(COH)CO 2 Et)(dppm) 2 ][CF 3 SO 3 ] (M = Os ( 8 ), Ru ( 9 )). The new diazoalkane-like group bridges the metals via the terminal nitrogen, while also binding to the group 8 metal via the enol carbon that originated from a carbonyl group. In the related reaction involving DEDM, substitution of a carbonyl yields [RhM(CO) 3 (μ-η 1:η 1 -N 2 C(CO 2 Et) 2 )(dppm) 2 ][CF 3 SO 3 ] (M = Os ( 10 ), Ru ( 11 )), in which the intact diazoalkane ligand again bridges via the terminal nitrogen. However, in this case one of the ester carbonyls binds to the group 8 metal, replacing the carbonyl group that was displaced. Although the RhRu compound 2 does not react with TMSDM, the analogous RhOs compound ( 1 ) does react, yielding [RhOs(CO) 3 (η 1 -Ν 2 CHSiMe 3 )(dppm) 2 ][CF 3 SO 3 ]] ( 12 ), in which the TMSDM ligand binds terminally on Os opposite the Rh−Os bond.
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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 | 0.000 | 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) | 0.000 | 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".