NNN-pincer-copper complex immobilized on magnetic nanoparticles as a powerful hybrid catalyst for aerobic oxidative coupling and cycloaddition reactions in water

A simple and reliable methodology is described for preparing the first heterogeneous NNN-pincer-copper hybrid catalyst with a high control over surface composition. The strategy relies on the covalently bonding of 2-aminopyridine to cyanuric chloride-functionalized magnetic nanoparticles followed by complexation with CuI. These claims are confirmed by different characterization methods such as SEM, TEM, FT-IR, TGA, ICP, XRD, and elemental analysis. The finely engineered supported catalyst is employed in the aerobic oxidative coupling of terminal alkynes and click reaction using only 0.38 and 0.04 mol% catalyst, respectively. All reactions perform under solvent-free condition or green solvent H₂O. Also, the catalyst is readily recovered and reused for up to 8 and 6 subsequent runs in click and homocoupling reactions without significant loss of activity or leaching.