Efficient Synthesis and Functionalization of 3-Bromonaphtho[2,3-b]thiophene
Why this work is in the frame
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Bibliographic record
Abstract
Abstract Naphtho[2,3-b]thiophene is a linear sulfur-containing polycyclic aromatic hydrocarbon. Naphtho[2,3-b]thiophene and its derivatives are commonly accessed by a Bradsher cyclization. Synthesis of the Bradsher cyclization substrate typically requires harsh conditions, including several oxidation state changes. Here, we report an improved, multigram synthesis of 3-bromonaphtho[2,3-b]thiophene, exploiting a copper-catalyzed cross-coupling to prepare the Bradsher substrate in three steps from commercial materials while minimizing redox reactions. In this work, the 3-bromonaphthothiophene is further functionalized via lithium–halogen exchange, with the key finding being a specific order of addition in lithiation is required to avoid undesired rearrangement reactions. Transformation to a versatile set of derivatives, including a naphthothiophene-containing chiral amine, is illustrated.
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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 | 0.000 | 0.001 |
| 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 | 0.000 |
| Insufficient payload (model declined to judge) | 0.013 | 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 it