Reductive–Oxidative Tandem Catalysis for Lignin Depolymerization to Benzoquinones and Benzaldehydes

This study investigates a tandem Pd-catalyzed reductive depolymerization of lignin and subsequent Co(salen)-catalyzed oxidative cleavage to obtain benzoquinones and benzaldehydes. The reductive depolymerization will result in lignin macromolecules with heavily increased phenolic OH content, which are then selectively cleaved by the Co(salen) catalyst to yield benzoquinones and benzaldehydes. Compared to lignin samples that do not undergo reductive depolymerization first, benzoquinone yields are substantially increased.