چکیده
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Lignin, an important aromatic biopolymer, is a major component of biomass. As a promising alternative to fossil resource 1, lignin has attracted much attention in recent years. It is considered to be the unique renewable aromatic resource and therefore represents a potentially valuable feedstock for the production of organic fine chemicals 2. Because of the complex and variable starting material, the valorization of lignin are often proceed through model compounds with β-O-4 linkage, which represents the most common substructure in lignin 3.
Herein we report the production of aldehydes by selective oxidation of 1° aliphatic alcohol in model compounds. TEMPO-mediated oxidation system, which composed by TEMPO (10% mol, TEMPO= 2,2,6,6-tetramethylpiperidine-N-oxyl) in combination with KBr (10% mol) and NaClO, was found effectively converting the primary hydroxyl groups of dilignols to carboxyl groups followed by retro-aldol bond cleavage. This catalyst system can also be applied for other lignin model compounds and organosolv lignin.
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