Novel bis(isobenzofuran)s and their utility in the synthesis of cyclophanes
Bibliographic record
Abstract
The synthesis of 1,2-bis(5-isobenzofuranyl)ethene by two routes is described. The first route involved generation of 1,2-bis(5-isobenzofuranyl)ethene from a bis(acetal) precursor under basic conditions. However, the synthesis was lengthy with low-yielding steps, which led to it being abandoned. The second route involved generation of 1,2-bis(5-isobenzofuranyl)ethene from a bis(oxabicyclic) precursor with 3,6-di(2'-pyridyl)-s-tetrazine. Napththo[1,2-c:5,6-c] difuran and 1,2-bis(5isobenzofuranyl)ethene were used to construct novel cyclophanes by double Diels-Alder reactions with bis(maleimide)s. NMR, AM1 modeling, and X-ray studies of the cyclophanes are discused. Attempts to prepare phenanthro[2,3-c:6,7-c] difuran and its cyclophanes are discussed. None was successful, and investigations were hampered by the inability to obtain sufficient quantities of starting materials. Finally, several suggestions are given for improving the syntheses of 1,2-bis(5- isobenzofuranyl)ethene, phenanthro[2,3-c:6,7-c]difuran, and their cyclophanes. Future directions, such as the functionalization of the double bond of 1,2-bis(5-isobenzofuranyl)ethene, aromatization of the oxabicyclic rings of the cyclophanes, and further X-ray studies are discussed.
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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) | 0.000 | 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) | 0.002 | 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 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".