Palladium-Catalyzed <i>N</i>‑Allylic\nAlkylation of Pyrazoles and Unactivated Vinylcyclopropanes

An efficient palladium-catalyzed <i>N</i>-allylic\nalkylation\nof pyrazoles and unactivated vinylcyclopropanes is demonstrated, affording\nvarious <i>N</i>-alkyl pyrazoles in ≤99% yield. This\nprotocol displays high atom economy, a broad range of substrates,\nand excellent regioselectivity and stereoselectivity. Late-stage modification\nof bioactive molecules, scaled-up reaction, and divergent derivatization\ndocumented the practicability of this methodology. The preliminary\nmechanistic investigation hinted that the Pd–H species promotes\nthe ring opening of cyclopropanes.