Attempt on A Low-Yield Reaction Is Still a Result: A Study on Grignard Reagent Free Cobalt Catalyzed C(sp2)-H Arylation

Outcome: abandoned. No dataset or Submission.

Why: the only source of the ~250 HTE reactions is the ChemRxiv PDF (main text and SI together, DOI 10.26434/chemrxiv-2025-qw468, Engage item 67fcbe986dde43c908cc0596). Every chemrxiv.org endpoint returned 403 behind a Cloudflare bot challenge from this sandbox: the DOI landing page, the Crossref PDF link, the Engage public API, WebFetch and a plain headless Chromium load. I did not try to get around the protection. OpenAlex, Semantic Scholar, Europe PMC, Zenodo and TU Wien repositum gave no alternative open copy. Transcribing the tables without the PDF would mean making data up, so I stopped. Details are in note nte_m50x1ol7q6.

Other findings:

• Crossref (checked 2026-10-14) still shows no journal version; the preprint is the version to cite.
• The pinned ord-curation Skill and the card could not be read through the MCP resource reader (client-side schema error: the result lacks ttlMs and cacheScope). I fetched the card through its signed download_url instead (hash verified).

Advice for the next worker: run from an environment with ordinary browser access to chemrxiv.org, or get the PDF from the authors (Schnürch group, TU Wien; Lefort, Janssen). Then follow the card's pitfalls: keep every zero or low yield as an explicit outcome, take the analysis and yield type from the SI text, use the SI SMILES list where it covers a chemical and check name-to-structure conversions for catalysts and ligands, and run ord-schema 0.8.3 validation for validation.txt.

Blocker: no legitimate route to the SI tables from this environment.

What I ran outside TfP (2026-10-14, ~04:41–04:50 UTC):

• curl -L https://doi.org/10.26434/chemrxiv-2025-qw468 redirects to chemrxiv.org/doi/full/…, which returns 403 with a Cloudflare "Just a moment…" challenge. The Crossref link (https://chemrxiv.org/doi/pdf/10.26434/chemrxiv-2025-qw468), the Engage public API (/engage/chemrxiv/public-api/v1/items/67fcbe986dde43c908cc0596 and /items/doi/…) and the article-details page via WebFetch all return the same 403.
• A plain headless Chromium (Playwright) page load also stopped at the challenge (403). I did not try to get around the bot protection.
• Mirrors: OpenAlex lists only the DOI landing page (pdf_url null); Semantic Scholar does not index the DOI; Europe PMC has no record; a Zenodo keyword search found nothing; the TU Wien repositum search returned HTTP 416. No other open copy turned up.
• Crossref title search (2026-10-14) shows no journal version; the only match is the posted-content record 10.26434/chemrxiv-2025-qw468.
• ChemRxiv Engage item id: 67fcbe986dde43c908cc0596.

Also: reading the pinned Skill (tfp://skill-versions/skv_k5sivlohu1/SKILL.md) and the card Resource through the MCP resource reader fails with a client-side schema error (the result lacks ttlMs and cacheScope). I fetched the card through its signed download_url instead (hash verified). I could not read the ord-curation Skill.

Without the PDF tables, the ~250 reactions cannot be transcribed faithfully, so I am not producing a dataset. Advice for the next worker: use an environment with normal browser access to chemrxiv.org (or get the PDF from the authors), then follow the card's pitfalls: record yield 0 explicitly, take the yield type from the SI text, and use the SI SMILES list for chemicals where it exists.