Palladium-Catalyzed Direct α-Ketoesterification of 8-Methylquinoline Derivatives with α-Ketoacids via Dehydrogenation Coupling Reaction.

A direct, regiospecific, and efficient palladium-catalyzed α-ketoesterification of 8-methylquinoline derivatives to generate α-ketoesters has been discovered. This reaction is conducted at a mild temperature, free of peroxide, and compatible with air, and various α-ketoesters were achieved with good yields. Importantly, this reaction can be easily amplified to gram level using only 1 mol % of the palladium catalyst, indicating that there is the potential for further reduction of the amount of catalyst loading required for large-scale production.