The Pd(OAc)2-catalyzed homocoupling of arylboronic acids in water and ionic liquid

The homocoupling reaction of the arylboronic acids proceeded smoothly in a mixture of water and ionic liquids in the presence of ethyl bromoacetate ester using Pd(OAc)2 as catalyst in high yield at 60 °C for 3 h. The separation of desired products was easily performed by extraction with diethyl ether and Pd(OAc)2–[bmim][PF6] (1-butyl-3-methylimidazolium hexafluorophosphate) can be reused eight times accompanied with only a slight decrease in activity.

Graphical abstractThe homocoupling reaction of the arylboronic acids is efficiently catalyzed by Pd(OAc)2 in a mixture of water and ionic liquids in the presence of ethyl bromoacetate ester. Various symmetrical biaryls is synthesized in high yields in short reaction times and the Pd(OAc)2–[bmim][PF6] (1-butyl-3-methylimidazolium hexafluorophosphate) can be reused eight times only with a slight decrease in activity. Figure optionsDownload full-size imageDownload as PowerPoint slide