A General and Mild Palladium‐Catalyzed Domino Reaction for the Synthesis of 2<i>H‐</i>Indazoles

Abstract

Practical and highly versatile, the reaction of readily available (2-chlorophenyl)acetylene and hydrazine substrates affords substituted 2H-indazoles in just a few hours under very mild reaction conditions (see scheme; DMF=N,N-dimethylformamide). The catalyzed domino sequence consists of a regioselective coupling followed by an intramolecular hydroamination and subsequent isomerization of the resulting exocyclic bond.