Triaryl phosphine-functionalized N-heterocyclic carbene ligands for Heck reaction

A new type of triaryl phosphine-functionalized imidazolium salts were prepared. Their palladium complexes, generated in situ, were successfully applied in the palladium-catalyzed Heck reaction. Using 1 mol% of Pd(dba)2 and 1 mol% in the presence of 2 equiv of K2CO3 in DMAc has proven to be highly efficient for the coupling of a wide array of aryl bromides and iodides with acrylates in excellent yield. The coupling of 4-bromotoluene with various styrene derivatives catalyzed by Pd/ complex also gave good results.