Palladium-Catalyzed N-Allylic Alkylation of Pyrazoles and Unactivated Vinylcyclopropanes

An efficient palladium-catalyzed N -allylic alkylation of pyrazoles and unactivated vinylcyclopropanes is demonstrated, affording various N -alkyl pyrazoles in ≤99% yield. This protocol displays high atom economy, a broad range of substrates, and excellent regioselectivity and stereoselectivity. Late-stage modification of bioactive molecules, scaled-up reaction, and divergent derivatization documented the practicability of this methodology. The preliminary mechanistic investigation hinted that the Pd–H species promotes the ring opening of cyclopropanes.