Facile Synthesis of β,β-(Radio)difluoroamines via Amino(radio)fluorination of α-Fluoroalkenes
Bibliographic record
Abstract
Given their prevalent presence in bioactive molecules, the synthesis of radiolabeled gem -difluoromethylene ([ 18 F]–CF 2 −) motifs is of practical relevance for radiotracer development. However, conventional strategies to construct [ 18 F]–CF 2 – motifs are limited, primarily relying on either 18 F-fluorination of bespoke precursors or multistep 18 F-difluoromethylation using radiosynthesized difluoromethylating reagents. Herein, a conceptually distinct alkene difunctionalization strategy is adopted in 18 F- gem -difluoromethylene synthesis, enabling an iron-catalyzed three-component amino(radio)fluorination of α-fluoroalkenes to furnish unprotected β,β-difluoroamines and their 18 F-labeled analogues. This transformation proceeds efficiently under low heat and air-insensitive conditions and accommodates a broad range of substrates, including complex drug-like molecules, without requiring prefunctionalized precursors. Mechanistic studies reveal a radical-polar crossover pathway involving an electrophilic N -centered radical addition and a subsequent nucleophilic ring-opening of an aziridinium intermediate to forge the C–F bond. This work effectively broadens the toolkit for the construction of complex 18/19 F- gem -difluoromethyl compounds.
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 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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 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 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".