58497-34-0Relevant academic research and scientific papers
Isolation of functionalized phenolic monomers through selective oxidation and CO bond cleavage of the β-O-4 linkages in Lignin
Lancefield, Christopher S.,Ojo, O. Stephen,Tran, Fanny,Westwood, Nicholas J.
supporting information, p. 258 - 262 (2015/02/19)
Functionalized phenolic monomers have been generated and isolated from an organosolv lignin through a two-step depolymerization process. Chemoselective catalytic oxidation of β-O-4 linkages promoted by the DDQ/tBuONO/ O2 system was achieved in model compounds, including polymeric models and in real lignin. The oxidized β-O-4 linkages were then cleaved on reaction with zinc. Compared to many existing methods, this protocol, which can be achieved in one pot, is highly selective, giving rise to a simple mixture of products that can be readily purified to give pure compounds. The functionality present in these products makes them potentially valuable building blocks.
SELECTIVE AEROBIC ALCOHOL OXIDATION METHOD FOR CONVERSION OF LIGNIN INTO SIMPLE AROMATIC COMPOUNDS
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Paragraph 0070, (2014/09/03)
Described is a method to oxidize lignin or lignin sub-units. The method includes oxidation of secondary benzylic alcohol in the lignin or lignin sub-unit to a corresponding ketone in the presence of unprotected primarily aliphatic alcohol in the lignin or lignin sub-unit. The optimal catalyst system consists of HNO3 in combination with another Br?nsted acid, in the absence of a metal-containing catalyst, thereby yielding a selectively oxidized lignin or lignin sub-unit. The method may be carried out in the presence or absence of additional reagents including TEMPO and TEMPO derivatives.
Electroorganic Reactions. 38. Mechanism of Electrooxidative Cleavage of Lignin Model Dimers
Pardini, Vera L.,Smith, Carmen Z.,Utley, James H. P.,Vargas, Reinaldo R.,Viertler, Hans
, p. 7305 - 7313 (2007/10/02)
The mechanisms for oxidative cleavage of several phenolic ethers, models for lignins, have been investigated by a detailed comparison of the results of anodic oxidation at nickel anodes in alkaline electrolyte with that of oxidation in acetonitrile in the presence of a triarylamine redox catalyst.The latter reaction is unambiguously initiated by single-electron transfer (SET), and in this case the major product of cleavage is aldehyde (vanillin or syringaldehyde derivatives).At nickel anodes polymerization is predominant although the aldehydes are formed together with larger amounts of the corresponding carboxylic acids.Combinations of 4-hydroxyl, α-keto, β-O-aryl, and β-hydroxymethyl functionality are shown to be crucial for the oxidation at nickel; the carboxylic acid formation probably involves a route with initial hydrogen atom abstraction at the surface.Important chemical conversions precede and accompany oxidation in alkaline media, and these are associated with the propensity for polymerization.
