Scope and limitations of ruthenium-catalyzed metathesis of simple polymer-bound alkenes
Bibliographic record
Abstract
Synthetic procedures for the preparation of two types of functional resin are described, both based on 2% cross-linked polystyrene with a high density (>60%) of side-chains and terminated by a primary alcohol. In the first case the C11 side-chain is linked to the polymer through a sulfide, and in the second an ether linkage is employed to incorporate a (CH2CH2O)4 unit. In both cases the resins have 13C NMR spectra that are informative in the chain terminus region without special operating conditions. Model intermolecular metathesis reactions were carried out on allylcarbamic acid tert-butyl ester and various alkenes with Grubbs' catalyst. On the basis of these experiments, gel-phase metathesis was successfully demonstrated between a polymer-bound allyl ether and simple symmetrical disubstituted alkenes, monitoring the extent of reaction by 13C NMR. These reactions did not go to completion even with recycling and some evidence for competing interchain metathesis is presented, based on the increased broadening and reduced mobility of the ensuing polymer.Key words: alkene metathesis, ruthenium, gel-phase, 13C NMR.
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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 | 0.002 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| 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".