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

Abstract 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 FeCl 3 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*RhCl 2 ] 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. magnified image