Heterogeneous Iron-Catalyzed Aerobic Oxidative Cleavage of C-C Bonds in Alcohols to Esters

A heterogeneous iron-based catalyst for the aerobic oxidative cleavage of C-C bonds in alcohols to access esters was developed. Various alcohols including inactive long-chain alkyl aryl alcohols as well as beta-O-4 lignin model compounds can be smoothly converted to the corresponding esters with molecular oxygen as the oxidant. Moreover, the present catalyst system can successfully degrade organosolv lignin. Base additives are not required except for inactive long-chain alkyl aryl alcohols. The catalyst exhibits good recyclability and can be easily recycled and reused up to seven times without a significant loss of catalytic activity. Characterization and control experiments confirmed that iron nanoparticles are mainly responsible for this reaction. Preliminary mechanism studies indicate that a sequential oxidation process exists in the reaction pathway.