Efficient and Mild Transfer Hydrogenolytic Cleavage of Aromatic Ether Bonds in Lignin-Derived Compounds over Ru/C

Cleavage of aromatic ether bonds is crucial for the valorization of lignin and its fragments, which is challenging under mild conditions because the bonds are very stable. Herein, we found that Ru/C could efficiently catalyze the cleavage of the aromatic ether bonds in various lignin-derived compounds via a transfer hydrogenolytic route using isopropanol as the hydrogen resource. Various lignin-derived compounds could be efficiently cleaved over commercial Ru/C to generate the corresponding aliphatic alkanes, aliphatic alcohols and aromatic derivatives under milder conditions. A mechanism study indicated that the reaction occurred through the direct cleavage of aromatic ether bonds or the formation of the reaction intermediate cyclohexyl phenyl ether.