Diastereoselective Addition of Allyl- and Crotylstannanes to Dicobalt-Complexed Acetylenic Aldehydes
Bibliographic record
Abstract
In an endeavor to utilize metal carbonyl complexes of acetylenic aldehydes and ketones to control the stereoselectivity of nucleophilic acyl addition, the dicobalt hexacarbonyl and dicobalt pentacarbonyl(triphenylphosphine) complexes of 3-phenylpropynal and 2-hexynal were conveniently prepared. Crotyl transfer from either ( E )- or ( Z )-crotyltributylstannane to Co 2 (CO) 6 -complexed 3-phenylpropynal and 2-hexynal produced 3,4-disubstituted-1,5-enynes with high syn diastereoselectivity. Allyl and 2-methylallyl transfer to Co 2 (CO) 5 PPh 3 -complexed aldehydes was also accomplished with high yields and diastereoselectivities. In all cases, decomplexation of the metal carbonyl moiety was effected, selectively, under very mild oxidative conditions. Exchange of a CO by PPh 3 led to decreased overall reactivity. Two competing kinetic processes were observed: stereoselective allylation was observed at low temperature, but at higher temperatures, the first formed allylic alcohol preferentially underwent elimination leading to dienynes.
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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 | 0.001 |
| 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) | 0.008 | 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".