Catalytic approaches for the selective preparation of cyclohexanone from lignin-based methoxyphenols/phenols

Abstract Biomass is the only alternative sustainable source of organic carbon for making fuels, polymers, and chemicals. Many reported methods are available for depolymerization of lignin to monomeric phenolic compounds. Brief discussion on these methods is covered. Hydrogenation-controlled hydrodeoxygenation of lignin-derived phenolic monomers is an emerging reaction tool in present scenario for preparation of cyclohexanol and cyclohexanone chemical intermediates. The prior-art on lignin based/model phenolic compounds for selective preparation of cyclohexanone based on Rh- and Pd metal catalysts are discussed in detail. The reported catalysts are active for simple phenol and alkylphenols to cyclohexanone and alkylcyclohexanones. The development of catalytic systems for hydroxy and methoxy substituted phenols conversion to unsubstituted (deoxygenated) cyclohexanone is still a challenging task in bio-refineries.