Sequential oxopyridinium betaine cycloaddition–palladium catalysed cyclisation–anion capture processes

Katritzkyʹs oxopyridinium betaine cycloaddition is employed to generate bridged bicyclic substrates suitable for our palladium(0) catalysed cyclisation–anion capture methodology. A variety of polycyclic heterocycles have been synthesised via monocyclisation–organotin(IV) capture with or without incorporation of carbon monoxide. Sequential cycloaddition–cyclisation can be performed as a one pot process to deliver substantial gain in molecular complexity.