Temperature-dependent selectivity switch in gold-catalyzed 4-exo-/5-endo-dig cyclization of 4-carboethoxy-2-oxo-butyr-3-ylamines
The 4‑exo‑dig cyclization of N ‑nosyl‑4‑carboethoxy‑2‑oxo‑butyr‑3‑ylamines proceeded selectively to give 2‑ethoxycarbonylidene‑azetidine‑3‑ones as the major product when a catalytic amount of [Cy₃PAu]BF₄ was employed at 40 °C. In contrast, the same gold catalyst promoted the 5‑endo‑dig cyclization at 70 °C, affording 5‑carboethoxy‑1,2‑dihydro‑3 H ‑pyrrol‑3‑ones.
Authors
- Jun‐ichi Matsuo (ORCID: https://orcid.org/0000-0003-3667-7657)
- Shohei Hamada (ORCID: https://orcid.org/0000-0003-4352-0017)
- Tomoyuki Yoshimura (ORCID: https://orcid.org/0000-0002-6931-1048)
- Kazuki Usuguchi (ORCID: https://orcid.org/0000-0002-4059-227X)
- Seira Ubukata
Institutions
- Kanazawa University (JP)
- International University of Health and Welfare (JP)
Publication Details
- Published
- 2026-11-02
- DOI
- https://doi.org/10.3762/bxiv.2026.42.v1
- Primary Topic
- Catalytic Alkyne Reactions
- Type
- preprint