Ligand‐controlled Regiodivergent C−H Alkenylation of Pyrazoles and its Application to the Synthesis of Indazoles

Regioselective C4‐, C5‐, and di‐alkenylations of pyrazoles were achieved. An electrophilic Pd catalyst generated by trifluoroacetic acid (TFA) and 4,5‐diazafluoren‐9‐one (DAF) leads to C4‐alkenylation, whereas KOAc and mono‐protected amino acid (MPAA) ligand Ac‐Val‐OH give C5‐alkenylation. A combina...

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