Cu-Catalyzed Synthesis of Imidazo[1,2-a]pyridines from α-Diazoketones and 2-Aminopyridines
J. S. Yadav*, B. V. Subba Reddy, Y. Gopal Rao, M. Srinivas, A. V. Narsaiah
Indian Institute of Chemical Technology, Hyderabad, India
22. November 2007 (online)
A synthesis of imidazo[1,2-a]pyridines by copper-catalyzed reaction of 2-aminopyridines with α-diazoketones is reported. The reaction proceeds in high yield under convenient and mild conditions from readily available starting materials. Although variation of R4, including a chiral example, was moderately explored, pyridine substitution was poorly investigated. A plausible mechanism involving a copper triflate catalyzed condensation of the aniline with the diazoketone, and subsequent ring closure via ejection of nitrogen was proposed.