Copper nanoparticles in ionic liquids: Recyclable and efficient catalytic system for 1,3-dipolar cycloaddition reaction

Copper nanoparticles were prepared in ionic liquids using a simple chemical reduction method. Spherical and cubical nanoparticles were obtained with ionic liquids BMIM.BF4 and BMIM.PF6, respectively. The nanoparticles showed excellent catalytic activity toward 1,3-dipolar cycloaddition between aryl and sugar based terminal alkynes and azides. Nanoparticles were effectively recycled without isolation from reaction medium and reused for five consecutive runs.