Palladium‐Catalyzed Site‐Selective C7 Oxidative Arylation of 4‐EWG‐1H‐Indazoles

Abstract An efficient palladium‐catalyzed oxidative arylation of substituted 1 H ‐indazole with various arenes and heteroarenes as coupling partners is reported. A site selective C7 oxidative arylation was perfectly achieved with a directing electron‐withdrawing groups (EWG) located at the C4 position of the 1 H ‐indazole. The desired products are obtained in moderate to good yields from 4‐NO 2 or 4‐CO 2 Me 1 H ‐indazoles and various (hetero)aryls as coupling partners in the presence of Pd(OAc) 2 as catalyst, phenanthroline as ligand, Ag 2 CO 3 as oxidant and NaOH as the base. Density functional theory was also conducted for reaction mechanism comprehension. This approach provides a highly effective, direct, and atom economical way to build C7‐ (het)arylated 1 H ‐indazole compounds.