Hydroxylamine Umpolung in Copper-Catalyzed Cross-Coupling Reactions to Synthesize <i>N</i>-Arylhydroxylamine Derivatives
Bibliographic record
Abstract
Hydroxylamine derivatives are well-established nitrogen precursors that undergo various transition metal-catalyzed transformations via the cleavage of the nitrogen–oxygen bond. Conversely, the development of a reagent containing a transferable electrophilic hydroxylamine has been elusive due to the inherent fragility of the N–O bond. Herein, we demonstrate the utility of hypervalent iodine chemistry to synthesize a reagent for the transfer of an electrophilic N–O moiety. Reagent 2 is a hydroxylamine umpolung that allows the formation of highly valuable N -arylhydroxylamine synthons via a copper-catalyzed cross-coupling reaction with boronic acids. The process with reagent 2 showed a wide functional group tolerance, especially with other electrophilic functional groups, and exhibited an orthogonal reactivity compared to other methods for synthesizing N -arylhydroxylamine derivatives. These can be subjected to Cope rearrangement and postfunctionalization, affording a variety of nitrogen-containing building blocks. Experimental and in silico mechanistic studies propose a catalytic cycle that involves the formation of a copper(II)-hydroxylamine species as the initial step. This species then reacts with boronic acid to produce the desired product.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 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".