Unique Tandem Heck-Lactamization Naphthyridinone Ring Formation between Acrylanilides and Halogenated Pyridines

The Heck coupling of acrylanilides with 4-bromo-2-chloro-3-iodo-pyridine using palladium acetate can produce bis-Heck products or undergo an unusual tandem Heck-lactamization ring formation to generate 5-chloro-1-aryl-1,6-naphthyridin-2(1H)-ones.