Cross-Linking of Brominated Poly(isobutylene-<i>c</i><i>o</i>-isoprene) by N-Alkylation of the Amidine Bases DBU and DBN
Bibliographic record
Abstract
An unusual cross-linking of brominated poly(isobutylene- co -isoprene), BIIR, has been shown to occur in the presence of the normally nonnucleophilic amidine bases 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and 1,5-diazabicyclo[4.3.0]non-5-ene (DBN). Model compound studies using brominated 2,2,4,8,8-pentamethyl-4-nonene (BPMN) have provided structural information which indicates that this cross-linking most likely occurs through a sequence of reactions which involves the following: (1) N-alkylation of the amidine base to an amidinium salt, (2) hydrolysis of the salt to an ammonium lactam, (3) deprotonation of the ammonium lactam to an amino-lactam, and (4) a second amine N-alkylation. The ability of DBU and DBN to undergo N-alkylation with BIIR has been confirmed by reaction of BIIR in solution with an excess of each of these bases to give N-alkylation products that have been characterized spectroscopically.
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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) | 0.001 | 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".