The reactivity of 6-haloimidazo[1,2-a]pyridine toward different azoles is reported. The process was shown to be highly dependent on the reaction conditions. Using copper(I) catalyst, the product of ipso substitution was obtained. In the absence of copper, with cesium carbonate in N,N-dimethylformamide, a cine substitution took place.
“Ipso- or Cine-Substitutions of 6-Haloimidazo[1,2-a]pyridine Derivatives with Different Azoles Depending on the Reaction Conditions”, J. Org. Chem., 2003, 68(14), 5614-5617.