Silver(I) triflate-catalyzed post-Ugi synthesis of pyrazolodiazepines

• Muhammad Hasan,
• Anatoly A. Peshkov,
• Syed Anis Ali Shah,
• Andrey Belyaev,
• Chang-Keun Lim,
• Shunyi Wang and
• Vsevolod A. Peshkov

Beilstein J. Org. Chem. 2025, 21, 915–925, doi:10.3762/bjoc.21.74

• ; pyrazolodiazepines; silver catalysis; Ugi reaction; Introduction Synthetic chemists are continuously involved in the development of methodologies for accessing new heterocyclic scaffolds that resemble naturally occurring products and biologically active molecules [1][2]. Nitrogen heterocycles draw particular

• pyrazolodiazepines 16a–d were obtained in consistently high yields of 84–96%. Notably, the synthesis of the parent pyrazolodiazepine 16a was scaled up to 3.5 mmol without a substantial decrease in isolated yield. To explore the influence of the amine component on the process, an extensive subset of aniline-derived

• substrates 15e–l was tested. The process proceeded efficiently in all cases, yielding pyrazolodiazepines 16e–l and demonstrating tolerance for various substituents on the aniline-derived aromatic fragment, including alkyl, halogens, electron-donating alkoxy groups, as well as electron-withdrawing