Mechanistic Studies of the Addition of Carbonyl Compounds to Tetramesityldisilene and Tetramesitylgermasilene
Bibliographic record
Abstract
The mechanism for the addition of carbonyl compounds to disilenes and germasilenes was investigated by examination of the structure of the products obtained from the reaction of the modified mechanistic probe, trans, trans -2-methoxy-3-phenylcyclopropane carbaldehyde, with tetramesityldisilene and tetramesitylgermasilene. The aldehyde was found to undergo characteristic ring-opening reactions depending on whether a radical or a cation develops at the carbinyl carbon. Thus, reaction of the mechanistic probe under ionic conditions ( p -TsOH) yielded a mixture of cis - and trans -2-methoxy-3-phenyl-2,3-dihydrofuran ( 6 ) from ring-opening toward the methoxy substituent. In contrast, reaction of the mechanistic probe under radical conditions (HSi(SiMe 3 ) 3, AIBN) yielded a mixture of cis- and trans- 3-methoxy-4-phenyl-1-[tris(trimethylsilyl)siloxy]but-1-ene ( 7 ) from regioselective ring-opening toward the phenyl substituent. 2,2,3,3-Tetramesityl-4-phenyl-5-methoxyoxa-2,3-disilacyclohept-6-ene ( 8 ) was formed from the reaction between the aldehyde and tetramesityldisilene, and a mixture of three isomers of 2,2,3,3-tetramesityl(phenyl)(methoxy)oxagermasilacyclohept-6-ene ( 10a − c ) and [dimesityl(1-oxa-4-methoxy-5-phenylpentadienyl)silyl]germane ( 10d ) was formed in the reaction of the aldehyde with tetramesitylgermasilene. The formation of 8, 10a, 10b, and 10d provides unequivocal evidence for the presence of radical intermediates in the addition of carbonyl compounds to the disilene and germasilene.
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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) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| 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".