Universal Reagent for Mild and Stereospecific Nucleophilic Substitution of Alcohols with Amines
Bibliographic record
Abstract
Abstract A user‐friendly reagent for mild and general activation of alcohols towards bimolecular nucleophilic substitution (S N 2) leveraging diverse nucleophiles, including primary and secondary amines is reported herein. The new ion‐paired reagent discovery was based upon the putative zwitterionic betaine intermediate of the Mitsunobu reaction and enabled the one‐step conversion of enantioenriched alcohols to valuable chiral C−X bonds (where X=N, C, S, O or halide). The described activating reagent has also been applied to a one‐step methylation reaction using methanol and to an intermolecular amination/intramolecular cyclization sequence that generates heterocycles, such as tetrahydroisoquinolines. This work provides the first evidence by X‐ray crystallography of a protonated betaine as intermediate in the Mitsunobu reaction.
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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 | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 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".