Copper-based nanocatalysts produced via laser-induced ex situ generation for homo- and cross-coupling reactions

In this work, we propose the promising approach that provides conditions for laser-induced ex situ synthesis of Raney-like copper-based nanostructured catalysts. Their catalytic activity and selectivity were investigated in Cu-catalyzed acetylene homo-coupling, Pd/Cu-catalyzed the Sonogashira cross-coupling and Cu-catalyzed azide-alkyne cycloaddition (CAAC). It was found that the growth of particles generated within the focus of the laser beam can last even if laser irradiation is off and can be controlled by adding phenanthroline to the reaction mixture as the stabilizing ligand or by increasing its temperature and concentration. Particle size of the synthesized copper-based catalysts significantly affects the reaction selectivity. Thus, it is possible to manage the course of the catalytic reaction towards formation of either homo-coupling or cross-coupling products by changing the size of the catalytically active copper-containing particles produced during laser-induced synthesis. (C) 2020 Elsevier Ltd. All rights reserved.