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DOI: 10.1055/s-0028-1087853
Copper Zeolites Catalyzed Homocoupling of Terminal Alkynes
Contributor(s):Yasuhiro Uozumi, Yoichi M. A. Yamada, Hidetoshi OhtaUniversité L. Pasteur and ECPM, Strasbourg, France and Ayya Nadar Janaki Ammal College, Siyakasi, India
Copper-Zeolites as Catalysts for the Coupling of Terminal Alkynes: An Efficient Synthesis of Diynes
Eur. J. Org. Chem. 2009, 423-429
Publication History
Publication Date:
23 March 2009 (online)
Key words
zeolites - copper - alkynes - homocoupling
Significance
Copper(I)-modified USY zeolite (CuI-USY) was prepared with the perspective to use it for the homocoupling of terminal alkynes 1. Thus, NH4-USY was heated at 550 ˚C to give H-USY. Then, a mixuture of H-USY and CuCl was heated at 350 ˚C under nitrogen flow to afford CuI-USY (pore size 7.4 Å). The reaction of 1 was carried out in the presence of CuI-USY at 110 ˚C under air to yield the corresponding diynes 2 (14 examples, 20-98% yield).
Comment
The reaction efficiency was strongly affected by the zeolite pore size. Cu(I)-modified Y (pore size 7.4 Å), β (pore size 6.4-5.5 Å), ZSM5 (pore size 5.3-5.1 Å), and MOR (pore size 6.5-3.4 Å) zeolites afforded the homocoupling products in 84, 19, 12, and 5% yields, respectively. CuAl-immobilized hydrotalcite (B. C. Zhu, X. Z. Jiang Appl. Organomet. Chem. 2007, 21, 345) and KF/alumina with Cu(OAc)2˙H2O (A. Sharifi, M. Mirzaei, M. R. Naimi-Jamal Monatsh. Chem. 2006, 137, 213) for the homocoupling of terminal alkynes were reported so far.