Iron porphyrin-catalyzed oxidation of 1,2-dimethoxyarenes: a discussion of the different reactions involved and the competition between the formation of methoxyquinones or muconic dimethyl esters

Abstract

This paper describes the oxidation of an α,β-diarylpropane lignin dimer model and other dimethoxyarenes by several iron porphyrin-based biomimetic systems. From 1-(3,4-dimethoxyphenyl)-2-phenylpropanol (1), three types of products are identified: the 3,4-dimethoxybenzaldehyde derived from the C α -C β cleavage of the propyl side chain and either quinones or muconic dimethyl esters resulting from oxidations at the level of the dimethoxyaryl group. The selectivity of the reaction is discussed with respect to the nature and reactivity of the high-valent iron-oxo species formed upon reaction of the oxidants, H 2 O 2 or magnesium monoperoxyphthalate (MMP), with the iron porphyrins