The di-copper-substituted gamma-Keggin-type silicotungstate TBA(4)[gamma-H(2)SiW(10)O(36)Cu(2)(mu-1 1-N(3))(2)] (1 TBA=tetra-n-butylammonium) could act as an efficient reusable homogeneous catalyst for the aerobic oxidative alkyne homocoupling Various kinds of structurally diverse terminal alkynes including aromatic heteroaromatic aliphatic double bond-containing silylacetylene propargylic alcohol and propargylic amine derivatives could selectively be converted into the corresponding diynes in the presence of I The catalytic activity of I was much higher than those of the mono-copper-substituted silicotungstate monomeric copper complexes and simple copper salts showing that the di-copper core in I plays an Important role in the present alkyne homocoupling The reaction mechanism involving the formation of the di-copper(II)-alkynyl intermediate reductive elimination of a diyne and re-oxidation of reduced copper species by O(2) has been proposed (C) 2010 Elsevier B V All rights reserved