One‐Pot Synthesis of Sulfonylated 5‐Aroyl‐2‐Arylpyridines via Ruthenium‐Catalyzed and K 2 S 2 O 8 ‐Mediated Domino Annulation of β‐Ketosulfones with DMF

Ruthenium‐catalyzed and K 2 S 2 O 8 ‐mediated synthesis of diverse sulfonylated 5‐aroyl‐2‐arylpyridines was developed through one‐pot stepwise annulation of two molecules of β‐ketosulfones and N , N ‐dimethylformamide (DMF) under the sealed tube conditions. In the overall process, DMF acts as the synthon of one carbon and one imino moiety in the construction of pyridine skeleton via cascade formation of single (C−C/C−N) and double (C=C/C=N) bonds under refluxing DMF conditions. Plausible reaction mechanism is proposed and discussed.