Palladium-catalyzed oxidative annulation of acrylic acid and amide with alkynes: a practical route to synthesize α-pyrones and pyridones.

A range of internal alkynes smoothly underwent palladium-catalyzed oxidative annulations with acrylic acid and amide to afford α-pyrones and pyridones in good to excellent yields with high regioselectivity. The usage of O2 (1 atm) as a stoichiometric oxidant with H2O as the only byproduct under mild conditions makes this process more attractive and practical.