Palladium-Catalyzed Asymmetric Aminomethylative Pyridonation of Conjugated Dienes

A novel palladium-catalyzed asymmetric aminomethylative pyridonation of conjugated dienes with N,O-acetals and 2-hydroxypyridines was established, which provided a direct and reliable method for the synthesis of a wide range of γ-aminated N-substituted 2-pyridones with good to excellent enantioselectivities. The simple BF₃ was identified as an effective cocatalyst to improve the reaction efficiency, and DFT calculations revealed that proton transfer between the aminomethylated allylic palladium species and 2-hydroxypyridine promoted by BF₃ is crucial for obtaining good reactivity.