22317-35-7Relevant articles and documents
Mechanochemical cleavage of lignin models and ligninviaoxidation and a subsequent base-catalyzed strategy
Dushkin, Alexandr V.,Su, Weike,Sun, Chen,Xu, Wenhao,Zheng, Lei
supporting information, p. 3489 - 3494 (2020/07/30)
Mechanochemical cleavage of lignin dimer model compounds to phenolic monomers has been developedviaa two-step strategy under milling conditions. In the first step of this process, the secondary benzylic alcohol of lignin β-O-4 linkages was selectively oxidized to the corresponding ketones over a 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ)/NaNO2catalytic system under milling conditions. In the subsequent step, mechanochemical selective cleavage of the Cβ-O bonds and Cα-Cβbonds of lignin β-O-4 ketones to acids and phenols was promoted by NaOH-catalyzed depolymerization. In addition, this two-step strategy was performed to depolymerize organosolv birch lignin, giving aromatic monomers with good selectivity for syringate. This approach provides an efficient method to convert the β-O-4 linkages of lignin to valuable aromatic monomers under mild reaction conditions.
Method for synthesizing guaiacyl glycerol-beta-guaiacyl ether from lignin beta-O-4 linkage dimer model compound
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, (2017/08/25)
The invention provides a method for synthesizing guaiacyl glycerol-beta-guaiacyl ether from a lignin beta-O-4 linkage dimer model compound. The content of beta-O-4 linkages in all linkages of lignin is highest and about 40-60%, so research of the beta-O-4 linkage lignin model compound plays an important role in research of the structure of lignin and the reaction mechanism of lignin in reaction. The method is simple, reaction conditions are mild, the yield is high, and the production period is short.
Selective aerobic benzylic alcohol oxidation of lignin model compounds: Route to aryl ketones
Dawange, Monali,Galkin, Maxim V.,Samec, Joseph S. M.
, p. 401 - 404 (2015/03/04)
A mild and chemoselective oxidation of the α-alcohol in β-O-4'-ethanoaryl and β-O-4'-glycerolaryl ethers has been developed. The benzylic alcohols were selectively dehydrogenated to the corresponding ketones in 60-93-% yield. A one-pot selective route to aryl ethyl ketones was performed. The catalytic system comprises recyclable heterogeneous palladium, mild reaction conditions, green solvents, and oxygen in air as oxidant. Catalytic amounts of a coordinating polyol were found pivotal for an efficient aerobic oxidation. The ligninator: A mild and chemoselective oxidation of the α-alcohol in β-O-4' lignin model compounds is developed. The benzylic alcohols are selectively dehydrogenated to the corresponding ketones in 60-93-% yield. A one-pot selective route to aryl ethyl ketones is performed. The catalytic system comprises recyclable heterogeneous palladium, mild reaction conditions, green solvents, and oxygen in air as oxidant.