Palladium-Catalyzed Olefination of 4H-Benzo[d][1,3]oxazin-4-one Derivatives with Activated Alkenes via Preferential Cyclic Imine-N-Directed Aryl C-H Activation

A palladium-catalyzed chelation-assisted selective ortho C-H bond olefination of biologically active 4H-benzo[d][1,3] oxazin-4-one derivatives with activated olefins has been achieved. The products are obtained in good yields with high regio- and stereoselectivities. This new protocol has been demonstrated to provide a variety of olefinated-4H-benzo[d][1,3]oxazin-4-one derivatives. The site selectivity of the reaction was explained by a DFT study.