A novel ruthenium-catalyzed cyclization of ketoxime carboxylates with N,N-dimethylformamide (DMF) for the synthesis of tetrasubstituted symmetrical pyridines has been developed. A methyl carbon on DMF performed as a source of a one carbon synthon. And NaHSO3 plays a role in the reaction.

A novel and efficient iron-catalyzed cyclization of ketoxime carboxylates and N,N-dialkylanilines for the modular synthesis of diverse pyridines was developed. The reaction was initiated by Fe-catalyzed N-O bond cleavage of ketoxime carboxylates in the presence of tertiary anilines. The methylene carbon on N,N-dialkylanilines functioned as a source of one-carbon synthon in the reaction. The reaction used readily available starting materials, tolerated various functional groups, and afforded 2,4-disubstituted and 2,4,6-trisubstituted pyridines in good to high yields under mild conditions.

A novel and efficient palladium(II)-catalyzed alkenyl C-H activation oxidative annulation of enamides with alkynes for the synthesis of substituted pyrroles has been developed. The reaction tolerates a wide range of functional groups and is a reliable method for the synthesis of triaryl-substituted pyrroles in high yields.