Silica/chitosan core-shell hybrid-microsphere-supported CuI catalyst for terminal alkyne homocoupling reaction

A new microfluidic approach to prepare silica/chitosan core-shell hybrid microspheres was developed. The hybrid microspheres exhibit improved mechanics and adsorption properties. In addition, the silica/chitosan-supported CuI is an outstanding catalyst for terminal alkyne homocoupling reaction. Because there is chitosan with a large amount of -NH₂, which has a strong force with metal ions, on the shell of the microspheres, the chitosan can effectively reduce mass transfer resistance. Meantime, the chitosan can adsorb reactants and subsequently increase the reactant concentration around the catalyst. These two reasons make this solvent-free reaction complete within 10 min at room temperature. It is easy to recover the catalyst simply through sedimentation by centrifuge. Furthermore, the silica/chitosan-supported catalyst can be reused many times with high catalytic activity.