摘要
A facile and practical synthetic route of unsymmetrical 1,3-diynes via the PdC1/CuI catalyzed oxidative coupling of two different terminal alkynes has been developed by using 3-（diphenylphosphino）propanoic acid as a ligand in the presence of oxygen. This system is suitable for not only aromatic alkynes but also heteroaromatic and aliphatic alkynes which were transformed into the corresponding unsymmetrical 1,3-diynes in moderate to good yields at room temperature. Moreover, the unsymmetrical 1,3-diynes were also obtained on a multi-gram scale. Mechanistic studies suggest that oxygen plays a key role in the catalytic cycles.
A facile and practical synthetic route of unsymmetrical 1,3-diynes via the PdC1/CuI catalyzed oxidative coupling of two different terminal alkynes has been developed by using 3-（diphenylphosphino）propanoic acid as a ligand in the presence of oxygen. This system is suitable for not only aromatic alkynes but also heteroaromatic and aliphatic alkynes which were transformed into the corresponding unsymmetrical 1,3-diynes in moderate to good yields at room temperature. Moreover, the unsymmetrical 1,3-diynes were also obtained on a multi-gram scale. Mechanistic studies suggest that oxygen plays a key role in the catalytic cycles.
基金
We gratefully acknowledge the financial support of this work by the National Natural Science Foundation of China （Nos. 21563025, 21463022）, Shihezi University Training Programme for Distinguished Youth Scholars （No. 2014ZRKXJQ05）, and Start-Up Foundation for Young Scientists of Shihezi University （No. RCZX201408）.
