Palladium-Catalyzed\nTandem Reaction of β‑Ketonitriles\nwith Arylboronic Acids and Dimethyl Sulfoxide: Application to Multicomponent\nSynthesis of Poly-Substituted Pyridines

The\nPd-catalyzed multicomponent tandem reaction of β-ketonitriles,\narylboronic acids and DMSO was efficiently developed, enabling access\nto a variety of poly substituted pyridines. The protocol shows excellent\nchemoselectivity, generating nicotinonitriles or symmetrical tetrasubstituted\npyridines under different conditions by tandem cyclization of enaminone\nintermediates with β-ketonitriles or enolates, respectively,\nand does not require extra ammonias. This method boasts notable advantages,\nsuch as the use of commercially available or easily prepared substrates,\nsimple conditions, a broad substrate scope, and good functional group\ntolerance.