Synthesis of a Hexameric Magnesium 4-pyridyl Complex with Cyclohexane-like Ring Structure via Reductive C-N Activation

The reaction of [{((Ar)nacnac)Mg}(2)] ((Ar)nacnac = HC{MeC(NAr)}(2), Ar = 2,6-diisopropylphenyl, Dip, or 2,6-diethylphenyl, Dep) with 4-dimethylaminopyridine (DMAP) at elevated temperatures afforded the hexameric magnesium 4-pyridyl complex [{((Ar)nacnac)Mg(4-C(5)H(4)N)}(6)] via reductive cleavage of the DMAP C-N bond. The title compound contains a large s-block organometallic cyclohexane-like ring structure comprising tetrahedral ((Ar)nacnac)Mg nodes and linked by linear 4-pyridyl bridging ligands, and the structure is compared with other ring systems. [((Dip)nacnac)Mg(DMAP)(NMe(2))] was structurally characterised as a by-product.