Reversible oxidative insertion of a C=C bond into magnesium(I) dimers:generation of highly active 1,2-dimagnesioethane compounds

The oxidative insertion of 1,1-diphenylethylene into the Mg-Mg bond of two magnesium(I) dimers, [(ArNacnac)Mg−]2 (Ar = C6H2Me3-2,4,6 (Mes); C6H3Et2-2,6; R = Et (Dep)), yielding 1,2-dimagnesioethane products, [{(ArNacnac)Mg}2(μ-CH2CPh2)], is described. These reactions are readily reversible at room temperature, proceeding via reductive elimination of the olefin. Thus, the reactions represent the first examples of room temperature reversible redox processes for s-block metal complexes. The 1,2-dimagnesioethane products are highly activated magnesium alkyls, and show unprecedented, uncatalyzed reactivity towards, H2, CO and ethylene. Computational studies have investigated the mechanisms of all presented reaction types