Iron-catalysed oxidative cleavage of lignin and beta-O-4 lignin model compounds with peroxides in DMSO

Simple FeCl3-derived iron catalysts are used for the cleavage of beta-O-4 linkages in lignin and lignin model compounds. The degradation of the beta-O-4 linkages and the resinol structures in both organosolv and kraft lignin was proven by 2D-NMR (HSQC) experiments, and the oxidative depolymerisation of these lignin sources was confirmed by GPC. Key reactive species facilitating this cleavage are methyl radicals generated from H2O2 and DMSO.