FeCl 3 ⋅6H 2 O‐Catalyzed Intermolecular‐Cascade Cyclization of Acetoacetanilide: Aldehyde‐Tuned Synthesis to Valuable 2‐Pyridone Analogues

The first ever breakthrough toward activation of β-ketoacetanilide and subsequent C-C and C-N bond-forming intermolecular-cascade cyclization processes is demonstrated by development of the unprecedented Lewis acid property of non-toxic FeCl(3)⋅6H(2)O. Aromatic, aliphatic, α,β-unsaturated, chiral sugar-based and chromone aldehydes were regio- and stereoselectively cyclized with acetoacetanilides toward construction of valuable N-containing highly functionalized 2-pyridones (see scheme for an example).