Chemical conversion of β-O-4 lignin linkage models through Cu-catalyzed aerobic amide bond formation.
نویسندگان
چکیده
Methods for conversion of the lignin β-O-4 models into amide derivatives and phenols have been developed, which is achieved via chemo-selective oxidation of the secondary benzylic alcohol and subsequent Cu-catalyzed aerobic amide bond formation.
منابع مشابه
Non-oxidative vanadium-catalyzed C-O bond cleavage: application to degradation of lignin model compounds.
Lignocellulosic biomass has recently received great interest as a renewable source of fuel and chemicals. Among the three major components of non-edible lignocellulose (cellulose, hemicellulose, and lignin), extensive efforts have been made to convert cellulose into ethanol and other biofuels. In contrast, research on the conversion of lignin has been limited to its removal from biomass either ...
متن کامل(E)-α,β-unsaturated amides from tertiary amines, olefins and CO via Pd/Cu-catalyzed aerobic oxidative N-dealkylation.
A novel Pd/Cu-catalyzed chemoselective aerobic oxidative N-dealkylation/carbonylation reaction has been developed. Tertiary amines are utilized as a "reservoir" of "active" secondary amines in this transformation, which inhibits the formation of undesired by-products and the deactivation of the catalysts. This protocol allows for an efficient and straightforward construction of synthetically us...
متن کاملStudy on the Structural Change of Lignin during Auto-catalyzed Ethanol-water Pulping of Aspen by H-nmr
This study concerns the structural change of lignin during auto-catalyzed ethanol-water pulping of aspen by 1H-NMR. The results showed that the linkages of alkyl-aryl ether of lignin, such as the α-ether linkages (α-O-4) and the β-ether linkages (β-O-4), were broken and the alkyl part formed carbenium at the Cα and Cβ of the aliphatic branch. Meanwhile, the aryl part of ether accepted one H and...
متن کاملStudies on the Vanadium-Catalyzed Nonoxidative Depolymerization of Miscanthus giganteus-Derived Lignin
Lignin samples isolated from Miscanthus giganteus using organosolv processes were treated with vanadium catalysts that were previously developed in our group. We demonstrate that the catalyst with high β-O-4′ bond-cleaving activity in dimeric lignin models was also effective in depolymerizing actual lignin. Molecular weight-lowering was evidenced by gel permeation chromatography (GPC), whereas ...
متن کاملCopper-catalyzed aerobic oxidative functionalization of an arene C-H bond: evidence for an aryl-copper(III) intermediate.
Recent studies have highlighted the ability of Cu(II) to catalyze the aerobic oxidative functionalization of C-H bonds; however, very little is known about the mechanisms of these reactions. Here, we describe the Cu(II)-catalyzed C-H methoxylation and amidation of a macrocylic arene substrate with O(2) as the stoichiometric oxidant. Kinetic and in situ spectroscopic studies demonstrate the invo...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Chemical communications
دوره 49 97 شماره
صفحات -
تاریخ انتشار 2013