The polymer-supported palladium(II) ethylenediamine complex, [PS-en-Pd(II)], is a highly active catalyst that could be used for the Sonogashira coupling reaction between an aryl iodide and 2-amino-3-(2-propynyl)-1,3-thiazolium bromide, 3. This heterogeneous palladium catalyst is efficient, stable, and recyclable. Reaction of compound 3 with various aryl iodides, 4a-f in the presence of the [PS-en-Pd(II)] complex leads to the production of the 6-(substituted benzyl)imidazo[2,1-b][1,3]thiazoles 5a-f.
Sonogashira coupling; heterogeneous catalyst; aryl iodides; imidazothiazoles
