Catalytic Oxidation by a Carboxylate-Bridged Non-Heme Diiron Complex

The synthesis of a sterically hindered di(μ-carboxylato)diiron(II) complex bearing terminal N,N‘,N‘ ‘-trimethyl-1,4,7-triazacyclononane (Me3TACN) ligands and its reaction with dioxygen to afford a (μ-oxo)di(μ-carboxylato)diiron(III) complex are described. Both compounds initiate catalytic oxo transfer with O2 as the terminal oxidant, converting phosphines to phosphine oxides, dimethyl sulfide to dimethyl sulfoxide, and dibenzylamine to benzaldehyde. Triphenylphosphine is oxidized to triphenylphosphine oxide with a turnover number of >2000 mol·P/mol·cat.