Cobalt-Mediated Selective Synthesis of Iodine Functionalized Imidazo-Fused Heterocycles Using 2-Aminopyridine, Styrene or Acetophenone

In this study, a cobalt-mediated approach toward the synthesis of iodinated imidazo-fused heterocycles employing molecular iodine as an iodine source, and 1,2-DCB as the sovent at 120 °C has been documented. An assortment of iodinated imidazo[1,2-a]pyridines were acquired in moderate to good yields (71%–84%) by using 2-aminopyridines and substituted styrenes as initial materials. This fine-tuned protocol has also been broadened with acetophenones in moderate to good yields (66%–90%). This protocol provides a straightforward pathway for the synthesis of iodoimidazo[1,2-a]pyridines. Iodoimidazo[1,2-a]pyridine was further derivatized to 2,3-diphenylimidazo[1,2-a]pyridine, an important biologically active molecule, with phenylboronic acid or simple benzene. Additionally, the gram scale reaction shows the high industrial applicability of the protocol.