Enhancing The Stability Of Aromatic Pcn Pincer Nickel Complexes By Incorporation Of Pyridine As The Nitrogen Side Arm

New PCNPy pincer nickel complexes have been synthesized through a short synthetic route. Incorporating pyridine as the nitrogen side arm facilitated the C-H activation in the PCN ligand and allowed the cyclometallation with nickel to take place at room temperature. Pyridine also enhanced the stability of beta-hydrogen-containing alkyl complexes. Also, the symmetric NCN nickel complex with pyridine side arms was successfully obtained giving a rare example of such type of complexes to be prepared through direct C-H activation. Furthermore, preliminary results showed that the (PCNPy)Ni-Br is active in Kumada coupling reactions particularly the coupling of aryl halides with aryl Grignard reagents.