Polymer Beads Decorated with Dendritic Systems as Supports for A3 Coupling Catalysts

The gel type microscopic polymer beads bearing epoxy functionalities were modified using the two-stage procedures in order to decorate their surface with the moieties of the zeroth order PAMAM type dendrimer and different heterocyclic aldehydes (2-pyridinecarboxaldehyde, 2-pyrrolidinecarboxaldehyde, furfural or 2-thiophenecarboxaldehyde). The polymeric supports provided in this manner were then used for the immobilization of copper(II) ions. The resulting materials were characterized using different instrumental techniques (optical microscopy, SEM, FTIR microscopy, DR UV–Vis, ICP-OES, and thermal analysis). They were also used as catalysts in the model A3 coupling reaction of benzaldehyde, morpholine and phenylacetylene. The best catalytic activity was found for the polymeric catalyst bearing 2-pyridinecarboxaldehyde moieties. It turned out to be effective in the A3 coupling reactions included different benzaldehyde, alkyne, and secondary amine derivatives, as well. It could also be recycled several times without a significant decrease in its activity in the model A3 coupling reaction.