Rhodium(III)‐Catalyzed Regioselective C‐H Annulation and Alkenylation of 2‐Pyridones with Terminal Alkynes

Cp*Rh(III)-catalyzed regioselective C−H annulation and alkenylation of 2-pyridones with terminal alkynes have been developed. The cationic Cp*Rh(III) catalytic system containing FeCl3 additive enables annulation of 1-(2-pyridyl)-2-pyridones with terminal alkynes, providing efficient access to 5,7-diarylated 2-quinolinones. The reaction pathway can be switched to alkenylation with [Cp*RhCl2]2 as the catalyst, NaOAc as the additive and HOAc as the solvent, affording C6-alkenylated 1-(2-pyridyl)-2-pyridones in high yields. These protocols accommodate a wide range of substrates with good functional group compatibility.