Role of Carbon–Carbon Phenyl Migration in the Pyrolysis Mechanism of β-O-4 Lignin Model Compounds: Phenethyl Phenyl Ether and α-Hydroxy Phenethyl Phenyl Ether

2012 ◽  
Vol 116 (50) ◽  
pp. 12242-12248 ◽  
Author(s):  
Ariana Beste ◽  
A. C. Buchanan
Keyword(s):  
Phenyl Ether ◽  
Model Compounds ◽  
Lignin Model Compounds ◽  
Pyrolysis Mechanism ◽  
Lignin Model

Tungsten-based catalysts for lignin depolymerization: the role of tungsten species in C–O bond cleavage

2019 ◽  
Vol 9 (9) ◽  
pp. 2144-2151 ◽  
Author(s):  
Haiwei Guo ◽  
Zaojuan Qi ◽  
Yuxuan Liu ◽  
Haian Xia ◽  
Lin Li ◽  
...  
Keyword(s):  
Bond Cleavage ◽  
Model Compounds ◽  
Lignin Model Compounds ◽  
Tungsten Species ◽  
Lignin Model ◽  
Lignin Depolymerization

Tungsten-based catalysts with designed tungsten species are synthesized and the role of each species in hydrocracking of both lignin model compounds and real lignin is deeply studied.

Peroxidations initiated by lignin model compounds: investigating the role of singlet oxygen in photo-yellowing

1998 ◽  
Vol 76 (12) ◽  
pp. 1805-1816 ◽  
Author(s):  
L. Ross C Barclay ◽  
Jennifer K. Grandy ◽  
Heather D. MacKinnon ◽  
Heather C. Nichol ◽  
Melinda R. Vinqvist
Keyword(s):  
Singlet Oxygen ◽  
Model Compounds ◽  
Lignin Model Compounds ◽  
Lignin Model

scholarly journals Isomer-dependent catalytic pyrolysis mechanism of the lignin model compounds catechol, resorcinol and hydroquinone

2021 ◽  
Author(s):  
Zeyou Pan ◽  
Allen Puente-Urbina ◽  
Andras Bodi ◽  
Jeroen A. van Bokhoven ◽  
Patrick Hemberger
Keyword(s):  
Synchrotron Radiation ◽  
Catalytic Pyrolysis ◽  
Reactive Intermediates ◽  
Product Formation ◽  
Model Compounds ◽  
Lignin Model Compounds ◽  
Pyrolysis Mechanism ◽  
Lignin Model ◽  
Catalytic Pyrolysis Mechanism

Detection of reactive intermediates with synchrotron radiation and photoelectron photoion coincidence methods reveals new mechanistic insights into lignin catalytic pyrolysis. Here we focus on how the isomerism changes the conversion and product formation.

A computational study of pyrolysis reactions of lignin model compounds

Holzforschung ◽  
2010 ◽  
Vol 64 (4) ◽  
Author(s):  
Thomas Elder
Keyword(s):  
Free Radicals ◽  
Computational Study ◽  
Closed Shell ◽  
Phenyl Ether ◽  
Electron Delocalization ◽  
Unimolecular Decomposition ◽  
Model Compounds ◽  
Lignin Model Compounds ◽  
Decomposition Reactions ◽  
Lignin Model

Abstract Enthalpies of reaction for the initial steps in the pyrolysis of lignin have been evaluated at the CBS-4m level of theory using fully substituted β-O-4 dilignols. Values for competing unimolecular decomposition reactions are consistent with results previously published for phenethyl phenyl ether models, but with lowered selectivity. Chain propagating reactions of free radicals with a closed-shell dilignol are dominated by structures in which extensive electron delocalization occurs.

Multi-steps degradation method for β-O-4 linkage in lignins: γ-TTSA method. Part 1: Reaction of non-phenolic dimeric β-O-4 model compounds

Holzforschung ◽  
2012 ◽  
Vol 66 (3) ◽  
Author(s):  
Daisuke Ando ◽  
Toshiyuki Takano ◽  
Fumiaki Nakatsubo
Keyword(s):  
Substitution Reaction ◽  
Phenyl Ether ◽  
Complex Structures ◽  
Model Compounds ◽  
Lignin Model Compounds ◽  
Sulfone Group ◽  
Carbohydrate Complex ◽  
Lignin Model

Abstract The so-called γ-TTSA method has been developed for the cleavage of β-O-4 linkages in lignin. It consists of four steps: (1) γ-tosylation, (2) thioetherification (substitution reaction with 1-dodecanethiol to γ-thioether), (3) sulfonylation (oxidation from γ-thioether to γ-sulfone), and (4) mild alkali degradation of γ-sulfone. The method was tested on non-phenolic dimeric β-O-4 lignin model compounds: 1G (4-benzyloxy-3-methoxyphenylglycerol-β-guaiacyl ether), 1S (4-benzyloxy-3,5-dimethoxyphenylglycerol-β-syringyl ether), and 1H (4-benzyloxyphenylglycerol-β-phenyl ether). It is demonstrated that the mild alkali degradation of the γ-sulfone group proceeds efficiently, i.e., the electron-withdrawing sulfone group at γ-position contributes to the cleavage of β-O-4 linkages. The γ-TTSA method may be especially useful for the elucidation of lignin-carbohydrate complex structures containing benzylether bonds.

scholarly journals Cleavage of aryl–ether bonds in lignin model compounds using a Co–Zn-beta catalyst

RSC Advances ◽  
2020 ◽  
Vol 10 (71) ◽  
pp. 43599-43606
Author(s):  
Xiaomeng Dou ◽  
Wenzhi Li ◽  
Chaofeng Zhu ◽  
Xiao Jiang ◽  
Hou-min Chang ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Metal Catalysts ◽  
Aryl Ether ◽  
Model Compounds ◽  
Lignin Model Compounds ◽  
Catalytic Hydrogenolysis ◽  
Lignin Model ◽  
Lignin Depolymerization

The catalytic hydrogenolysis of lignin model compounds containing aryl–ether linkages by Co–Zn-beta catalyst is investigated to understand the role of “Lewis acid-metal” catalysts in lignin depolymerization.

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