Synthesis of 4H-Indazol-4-ones and Fused Pyrazoles via Copper-Catalyzed Annulation of Hydrazones with Cyclic Enones

Nayak, K.H.Bhaskaran, R.P.Shamnad, A.Babu, B.P.2026-02-042023Asian Journal of Organic Chemistry, 2023, 12, 9, pp. -21935807https://doi.org/10.1002/ajoc.202300258https://idr.nitk.ac.in/handle/123456789/21744Herein, we report the synthesis of cyclic ketone-fused pyrazoles via [3+2] annulation reaction between hydrazones and cyclic enones (five-, six- and seven-membered) catalyzed by Cu(II) under aerobic conditions. These compounds were further functionalized by reactions such as Suzuki-Miyaura cross-coupling, Heck coupling, and Aldol reaction to afford diverse molecular scaffolds in good yield, selectivity and functional group tolerance. © 2023 Wiley-VCH GmbH.Copper catalystCyclic enoneIndazolePyrazole[3+2] AnnulationSynthesis of 4H-Indazol-4-ones and Fused Pyrazoles via Copper-Catalyzed Annulation of Hydrazones with Cyclic Enones