Highly stereoselective facile synthesis of β-amino carbonyl compounds via a Mannich-type reaction catalyzed by γ-Al <sub>2</sub> O <sub>3</sub> /MeSO <sub>3</sub> H (alumina/methanesulfonic acid: AMA) as a recyclable, efficient, and versatile heterogeneous catalyst
Bibliographic record
Abstract
Mannich reaction of ketones, aromatic aldehydes, and aromatic amines catalyzed efficiently by γ-Al 2 O 3 /MeSO 3 H (alumina/methanesulfonic acid: AMA) as a heterogeneous catalyst, which were carried out in EtOH at ambient temperature to afford the corresponding β-amino ketones in good yields and high stereoselectivities in favor of the anti isomer, was described for the first time. It was found that this catalyst could be completely recovered and reused without loss of its catalytic activities and is thus environmentally conscious. Furthermore, the use of γ-Al 2 O 3 /CH 3 SO 3 H (AMA) catalyst is feasible because of its easy preparation, easy handling, stability, easy recovery, reusability, good activity, stereoselectivity, and eco-friendliness. The use of this method provides a novel and improved modification of the three-component Mannich reaction in terms of mild reaction conditions and clean reaction profiles, using a very small quantity of catalyst and a simple workup procedure.
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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) | 0.001 | 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) | 0.001 | 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".