Palladium-catalyzed [4+2] cycloaddition of amido-tethered allylic carbonates with oxazol-5-(4H)-ones: synthesis of piperidine-2,6-dione derivatives

A palladium-catalyzed [4 + 2] cycloaddition of amido-tethered allylic carbonates with oxazol-5-(4H)-ones proceeded smoothly under mild reaction conditions to give various piperidine derivatives in moderate to excellent yields. The reaction worked via aza-1,4-dipole from in situ deprotonation of amido-tethered allyl carbonates.