A mild, efficient and stable copper iodide nanoparticle (CuI NP)-catalyzed regioselective synthesis of 3-nitro-2-arylimidazo[1,2-a]pyridines was developed. Substituted 2amino pyridines successfully reacted with both electron-rich and electron-deficient β-nitro styrenes to produce the desired products in good to excellent yields. Hot filtration tests confirmed the heterogeneous nature of the CuI NPs. The [a] D.

The Fe 3 O 4 À Pd nanoparticles catalyzed Heck coupling reaction in triethanolamine was performed for the first time in absence of any external ligand. The Fe 3 O 4 À Pd/triethanolamine/100°C catalytic system was found to be highly active in achieving good to excellent yields of the desired (E)-alkenes. Both acrylates and styrene derivatives were successfully coupled with electron-rich and electron-deficient aryl iodides. The scope of the reaction was also expanded to less reactive aryl bromides and aryl chlorides albeit in lower yields. A number of functional groups were well tolerated. More significantly the catalyst showed good recyclability and can be reused up to four consecutive cycles without any decrease in catalytic activity.