Efficient Construction of Five-Membered Aromatic and Nonaromatic Heterocycles from 1,6-Enynes by a Palladium-Catalyzed Domino Coupling/Cycloisomerization Process

General and efficient methods for the construction of five-membered aromatic and nonaromatic heterocycles by palladium-catalyzed coupling/cycloisomerization of 1,6-enynes and aryl halides have been developed. Results indicate that substituents at the terminus of the alkynes have a significant effect on the selective formation of the products.