Overriding Norrish Type II to Access Cyclopropanols
Bibliographic record
Abstract
The propensity for photoexcited aryl ketones to undergo 1,5-hydrogen atom transfer (HAT) reactions is a fundamental process in organic synthesis and polymer degradation. Since its discovery in 1958, Norrish-Yang photocyclization has become a prominent method to access cyclobutanols under mild photoirradiative conditions. Despite its successful extension to larger ring systems, access to medicinally relevant 3-membered rings remains limited due to the strong kinetic preference for 1,5-HAT over 1,4-HAT. In this work, we demonstrate the first photocyclization of β-boryl aryl ketones to cyclopropanols. Our strategy relies on solvent-controlled selective population of the π,π* triplet state over the n,π* triplet state, with the former preferentially undergoing 1,4-boryl group transfer over 1,5-HAT. This protocol proceeds under mild irradiative conditions with excellent functional group tolerance, providing access to a broad range of highly valuable cyclopropanol scaffolds.
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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) | 0.000 | 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) | 0.004 | 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".