Synthesis of ketones from biomass-derived feedstock

Cyclohexanone and its derivatives are very important chemicals, which are currently produced mainly by oxidation of cyclohexane or alkylcyclohexane, hydrogenation of phenols, and alkylation of cyclohexanone. Here we report that bromide salt-modified Pd/C in H₂O/CH₂Cl₂ can efficiently catalyse the transformation of aromatic ethers, which can be derived from biomass, to cyclohexanone and its derivatives via hydrogenation and hydrolysis processes. The yield of cyclohexanone from anisole can reach 96%, and the yields of cyclohexanone derivatives produced from the aromatic ethers, which can be extracted from plants or derived from lignin, are also satisfactory. Detailed study shows that the Pd, bromide salt and H₂O/CH₂Cl₂ work cooperatively to promote the desired reaction and inhibit the side reaction. Thus high yields of desired products can be obtained. This work opens the way for production of ketones from aromatic ethers that can be derived from biomass.