Investigation and optimization of metal- and organocatalyzed decarboxylative radical addition of carboxylic acids to Seebach-Beckwith dehydroalanine towards optically pure unnatural amino acids
Bibliographic record
Abstract
Four decarboxylative conjugate radical addition methods, including recent and greener methods using Fe- and Eosin Y as photocatalysts, were examined using Seebach-Beckwith dehydroalanine as a radical acceptor. Head-to-head comparison of yields and purity suggests that Ir-photocatalyzed decarboxylation of carboxylic acids is the optimal method for syntheses involving resonance-stabilized radicals. However, approaches relying on cheaper Ni-, Fe-, and Eosin Y-catalyzed processes are quite viable for the conjugate addition of 1°, 2°, and 3° radicals. • Decarboxylative Michael addition to a dehydroalanine gives chiral amino acid analogs. • Different methods of radical generation give different yields depending on structure. • Fe-catalyzed radical formation woks well for tertiary radical Michael addition. • Ir-catalyzed photodecarboxylation is expensive but most versatile for dehydroalanines. • Cheaper Ni & eosin Y catalysis works for conjugate addition of 1°, 2°, & 3° radicals.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".