Ag ₂ O Nanocrystals for Coupling Aldehydes, Amines, and Alkynes into Propargylamines

High Resolution Image Download MS PowerPoint Slide Ag 2 O cubes, octahedra, and rhombic dodecahedra have been synthesized to catalyze the coupling of aldehydes, amines, and alkynes, forming propargylamines. Rhombic dodecahedra exhibit the best catalytic activity. The interior and surface lattice variations should be factors in the activity differences. Despite the conversion of Ag 2 O crystals to Ag particles within 1 h of reaction, the in situ formed Ag particles were found to be catalytically active. In contrast, Ag cubes, which were pseudomorphically transformed from Ag 2 O cubes, gave very low product yields. X-ray photoelectron spectroscopy results indicate differences in their bonding environment. The Ag 2 O rhombic dodecahedra were used to synthesize a broad range of propargylamines. A reaction mechanism is proposed. It is envisioned that Ag 2 O polyhedra can be a superior choice to commercial Ag 2 O powder for other organic transformations.