BF3⋅OEt2‐Promoted Annulation for Substituted 2‐Arylpyridines as Potent UV Filters and Antibacterial Agents

A simple and efficient BF3⋅OEt2 mediated methodology for the construction of diverse 2‐phenylpyridines bearing benzophenone moieties from readily available 3‐formylchromones and phenylacetylenes in wet acetonitrile was developed. The nitrogen source for the pyridine construction was derived from acetonitrile. This one‐pot protocol proceeds via [3+2+1] annulation through cascade nucleophilic addition, hydrolysis, Michael‐type addition, ring opening, and elimination reactions. The synthesized compounds may have applications as UV filters and exhibit potent antibacterial activities.