Rh(III)-Catalyzed C-H Annulation of 3-Aryl-2H-benzo[e][1,2,4]thiadiazine-1,1-dioxides with Vinylene Carbonates

A novel method has been developed for the synthesis of fused dihydroisoquinoline frameworks through a Rh(III)-catalyzed annulation of 3-aryl-2H-benzo[e][1,2,4]thiadiazine-1,1-dioxides with vinylene carbonates by C-H bond activation. This is the first report on the oxidative C-H functionalization of aryl-2H-benzo[e][1,2,4]thiadiazine-1,1-dioxide with vinylene carbonate to afford angularly fused heterocycles in good yields with high functional group tolerance. In this approach, vinylene carbonate acts as a glycolaldehyde surrogate to construct the fused dihydroisoquinoline ring systems.