کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
56245 | 47078 | 2010 | 5 صفحه PDF | دانلود رایگان |
The di-copper-substituted γ-Keggin-type silicotungstate TBA4[γ-H2SiW10O36Cu2(μ-1,1-N3)2] (I, 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 O2 has been proposed.
Journal: Catalysis Today - Volume 157, Issues 1–4, 17 November 2010, Pages 359–363