One‐Pot Allan–Robinson/Friedländer Route to Chromen‐/Quinolin‐4‐ones through the Domino Acetylative Cyclisation of 2‐Hydroxy‐/2‐Aminobenzaldehydes

The domino synthesis of 2‐phenyl‐4 H ‐chromen‐4‐ones and quinolin‐4‐ones through acetylation of 2‐hydroxy‐/2‐aminobenzaldehydes with α‐haloketones followed by intramolecular oxa‐/azaheterocyclisation is reported. This method represents a new extension of the Allan–Robinson and Friedländer reactions, and uses N‐heterocyclic‐carbene catalysis to construct the target molecules in good to excellent yields: 86–95 % for the chromen‐4‐ones, and 83–96 % for the quinolin‐4‐ones. This approach has the advantages of operational simplicity, ambient reaction conditions, and no by‐product formation.