Manganese(III)-Mediated Formylation of Aromatic Compounds in the Presence of Malonic Acid

Article abstract of DOI:10.1246/bcsj.62.545

The reaction of naphthlenes with malonic acid in the presence of manganese(III) acetate gives naphthalenecarbaldehydes and naphthalenecarboxylic acids.Similar reactions of anthracene, pyrene, and methoxybenzenes also yield formylated and carboxylated products.It was found that the formyl group introduced to the aromatic ring was not derived from carboxymethyl radical generated directly by the thermolysis of manganese(III) acetate, but from a dicarboxymethyl radical formed by the interaction of malonic acid and manganese(III) acetate.In addition, it was also found that the dicarboxymethyl radicals attacked the position of the highest electron density on the aromatic ring and that this formylation was effective when the ionization potential of the aromatic copound was lower than 7.8 eV.