Sustainable Lignin Valorization: Ti(III)-Mediated Reductive Degradation Yielding Aromatic Monomers (Phenol and Styrene)

A Ti(III)-mediated cleavage of β-O-4 linkages in lignin to yield aromatic phenols and styrenes is reported. Under mild reaction conditions, this method achieves efficient and highly selective degradation of 28 structurally distinct lignin model compounds. Mechanistic studies indicate that the titanium-mediated cleavage proceeds via a radical pathway, rather than involving carbocation intermediates, offering a promising route for sustainable conversion of lignin into useful aromatic monomers.