Efficient P, O chelate palladium(II)/AgNO₃ cocatalyzed homocoupling of aromatic terminal alkynes in aqueous media under ambient atmosphere

GRAPHICAL ABSTRACT

ABSTRACT

A new and efficient protocol for the P, O chelate Pd(II)/AgNO₃ cocatalyzed oxidative homocoupling reaction of aromatic terminal alkynes in the synthesis of symmetrical 1,4-disubstituted-1,3-diynes was described in aqueous media under ambient atmosphere. The results showed that both NEt₃ and THF/H₂O (in 4:1 proportion) played crucial roles in the reaction. In contrast, this protocol employs a low palladium(II) complex loading and AgNO₃ as cocatalyst to obtain the homocoupled products in moderate to good yields.

KEYWORDS:

• Aromatic terminal alkynes
• P,O chelate Pd(II) complex/AgNO₃ cocatalyst
• homocoupling reaction
• 1,4-disubstituted-1,3-diynes

Acknowledgments

The authors thank the National Natural Science Foundation of China (No: 21363026) and the Scientific and Technological Landing Project of Higher Education of Jiangxi Province (No: KJLD13091).