Palladium-Catalyzed Direct Alkenylation of 2-Methyl-4H-pyrido[1,2-a]pyrimidin-4-ones Using Oxygen as the Oxidant.

A direct C-3 alkenylation of 2-methyl-4H-pyrido[1,2-a]pyrimidin-4-ones through palladium-catalyzed C–H activation using oxygen as the terminal oxidant has been developed. This method provides an easy access to functionalized new 2-methyl-4H-pyrido[1,2-a]pyrimidin-4-one derivatives.