Dendrimer-Encapsulated Copper Cluster as a Chemoselective and Regenerable Hydrogenation Catalyst

A copper cluster encapsulated within a poly(amidoamine) dendrimer with hydroxyl surface groups (PAMAM-OH) acted as a chemoselective catalyst for hydrogenation of carbonyl and olefin groups in water. The activity was dependent on the molar ratio of Cu2+ and PAMAM-OH used in the synthesis, which was ascribed to the size-specific chemical properties of Cu clusters. The dendrimer-encapsulated Cu cluster was oxidized into Cu2+ ions under aerobic conditions, but could be regenerated by reduction with NaBH4 for catalytic application.