Bhaskaran, R.P.Sreelekha, M.K.Babu, B.P.2026-02-042022ChemistrySelect, 2022, 7, 44, pp. -https://doi.org/10.1002/slct.202202773https://idr.nitk.ac.in/handle/123456789/22314The reactivity of various activated olefins towards the [3+2] annulation with hydrazones (aza-enamines) has been studied. Nitroolefins, methyl vinyl ketone, acrylates and acrylamide were found to react with aldehyde hydrazones of different electronic nature to generate 1,3,5-/1,3,4–trisubstituted pyrazoles selectively. A detailed optimization study was conducted to derive the best condition for the annulation reaction of different olefin partner and the intermediate dihydropyrazole is also identified. © 2022 Wiley-VCH GmbH.AcrylateHydrazoneMethyl vinyl ketoneNitroolefinPyrazole[3+2] annulation