A straightforward synthesis of 4,5-dihalofunctionalized imidazol-2-ylidene/imidazolyl-metal complexes from trihaloimidazolium salts/imidazoles: Structure and catalytic studies

Backbone dihalofunctionalized imidazol-2-ylidene/imidazolyl-metal complexes (5−13) of group–10 metal ions were synthesized through a proficient and single step oxidative addition method using 2,4,5-trihaloimidazolium salts or imidazoles respectively. The donor property of 4,5-diiodofunctionalized imidazol-2-ylidene was described for the first time. The catalytic activity of palladium complexes containing imidazol-2-ylidene (6 and 7)/imidazolyl (10 and 11) groups towards Suzuki-Miyaura coupling reaction of aryl bromides was evaluated and compared with its unsubstituted counterpart. Besides, the investigation of reaction pathway in catalysis was carried out.