Direct oxygen atom transfer versus electron transfer mechanisms in the phosphine oxidation by nonheme Mn(iv)-oxo complexes

Abstract

Direct oxygen atom transfer from a nonheme Mn(IV)-oxo complex, [(Bn-TPEN)Mn^IV(O)]²⁺, to triphenylphosphine (Ph₃P) derivatives occurs with a significant steric effect resulting from the ortho-substituents on the phenyl group of the Ph₃P derivatives, whereas the phosphine oxygenation by a Mn(IV)-oxo complex in the presence of HOTf occurs via an electron transfer mechanism without the substrate-steric effect.