Intramolecular C–C Bond Coupling of Nitriles to a Diimine Ligand in Group 7 Metal Tricarbonyl Complexes

Dissolution of M­(CO)₃(Br)­(L^Ar) [L^Ar = (2,6-Cl₂-C₆H₃-NCMe)₂CH₂] in either acetonitrile [M = Mn, Re] or benzonitrile (M = Re) results in C–C coupling of the nitrile to the diimine ligand. When reacted with acetonitrile, the intermediate adduct [M­(CO)₃­(NCCH₃)­(L^Ar)]Br forms and undergoes an intramolecular C–C coupling reaction between the nitrile carbon and the methylene carbon of the β-diimine ligand.