Unsymmetrical Saturated Ketones Resulting from Activations of Hydrocarbon C(sp<sup>3</sup>)–H and C(sp<sup>2</sup>)–H Bonds Effected by Cp*W(NO)(H)(η<sup>3</sup>-allyl) Complexes
Bibliographic record
Abstract
C–H activations of a C(sp 2 )–H bond in benzene or a C(sp 3 )–H bond in mesitylene at 80 °C under CO pressure in undried solvents without rigorous exclusion of air and moisture can be effected with the 18e complexes Cp*W(NO)(H)(η 3 -CH 2 CHCMe 2 ) ( 1 ), Cp*W(NO)(H)(η 3 -CH 2 CHCHMe) ( 2 ), and Cp*W(NO)(H)(η 3 -CH 2 CHCHPh) ( 3 ) (Cp* = η 5 -C 5 Me 5 ). These activations are regiospecific and afford in the case of complex 1 good yields of the unsymmetrical saturated ketones 4-methyl-1-phenylpentan-1-one ( 5 ) and 1-(3,5-dimethylphenyl)-5-methylhexan-2-one ( 8 ), respectively, in which the alkyl groups result from hydrogenation of the allyl ligand in the organometallic reactant. Complex 2 reacts similarly, but complex 3 only produces the ketone from its reaction with CO in benzene. Theoretical calculations indicate that the key mechanistic feature of these conversions is the formation of a 16e η 2 -alkene complex which is generated by the regiospecific migration of the hydride ligand onto the tertiary carbon of the allyl ligand. The 16e Cp*W(NO)(η 2 -CH 2 ═CHCHMe 2 ) and Cp*W(NO)(η 2 -MeCH═CHPh) intermediate complexes formed in this manner by complexes 1 and 3, respectively, have been trapped as the corresponding 18e CO adducts Cp*W(NO) (CO)(η 2 -CH 2 ═CHCHMe 2 ) ( 10 ) and Cp*W(NO) (CO)(η 2 -MeCH═CHPh) ( 11 ). All new complexes have been characterized by conventional spectroscopic and analytical methods, and the solid-state molecular structures of two isomers of 11 have been established by single-crystal X-ray crystallographic analyses. This new and facile method of synthesizing saturated unsymmetrical ketones via C–C bond formation not only is atom economical but also is part of a complete synthetic cycle, since Cp*W(NO)(CO) 2 ( 4 ) is the final organometallic product formed in all cases, and it can be readily reconverted to the hydrido allyl reactants 1 – 3 in three steps via Cp*W(NO)Cl 2 .
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 | 0.000 | 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) | 0.002 | 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".