Regioselective Copper-Catalyzed Dicarbonylation of Imidazo[1,2‑<i>a</i>]pyridines with N,N-Disubstituted Acetamide or Acetone: An Approach to 1,2-Diketones Using Molecular Oxygen

A novel copper-catalyzed regioselective double carbonylation of imidazo­[1,2-<i>a</i>]­pyridines with N,N-disubstituted acetamide or acetone using molecular oxygen has been described. It has provided a new approach to synthesize 1,2-carbonyl imidazo­[1,2-<i>a</i>]­pyridines, which are important substrates and intermediates in preparation of fine chemicals. The product shares a skeleton similar to that of Zolpidem, one of the most prescribed drugs in the world. <sup>18</sup>O-labeling experiments unambiguously established that the oxygen source of products originated from O<sub>2</sub> rather than H<sub>2</sub>O.