Abstract
We report the highly facet-dependent catalytic activity of Cu 2 O nanocubes, octahedra, and rhombic dodecahedra for the multicomponent direct synthesis of 1,2,3-triazoles from the reaction of alkynes, organic halides, and NaN 3 . The catalytic activities of clean surfactant-removed Cu 2 O nanocrystals with the same total surface area were compared. Rhombic dodecahedral Cu 2 O nanocrystals bounded by {110} facets were much more catalytically active than Cu 2 O octahedra exposing {111} facets, whereas Cu 2 O nanocubes displayed the slowest catalytic activity. The superior catalytic activity of Cu 2 O rhombic dodecahedra is attributed to the fully exposed surface Cu atoms on the {110} facet. A large series of 1,4-disubstituted 1,2,3-triazoles have been synthesized in excellent yields with high regioselectivity under green conditions by using these rhombic dodecahedral Cu 2 O catalysts, including the synthesis of rufinamide, an antiepileptic drug, demonstrating the potential of these nanocrystals as promising heterogeneous catalysts for other important coupling reactions. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.