Fe(III)-Catalyzed Tandem Cyclization of Phenylpropiolamides with 3‑Formylchromones for the Construction of 2‑Pyridones

A highly efficient and atom-economic iron(III)-catalyzed
three-component
heteroannulation reaction between phenylpropiolamides, 3-formylchromones,
and water is described for the construction of diversely multifunctionalized
2-pyridones. This protocol allows rapid access to a variety of 2-pyridones
bearing an ortho-hydroxybenzoyl and a benzoyl scaffold
under operationally simple conditions. The synthetic utility of the
synthesized 2-pyridone scaffolds is demonstrated by transformation
into biologically interesting complex heterocycles.