18256-48-9

Upstream product

• 284043-13-6 2-(4-hydroxy-3-methoxyphenyl)-2-oxoethyl-4-[(tert-butoxycarbonyl)amino]butanoate 
• 64-17-5 ethanol 
• 9005-53-2 lignin 
• 67-56-1 methanol 
• 97638-21-6 1-(4-benzyloxy-3-methoxyphenyl)ethane-1,2-diol 
• 93904-00-8 ethyl 4-(benzyloxy)-3-methoxymandelate 
• 52058-11-4 ethyl 4-hydroxy-3-methoxymandelate 
• 64-18-6 formic acid 
• 7382-59-4 guaiacylglycerol-β-guaiacyl ether 
• 74162-07-5 4-(2-diazoacetyl)-2-methoxyphenyl acetate 
• 50893-83-9 4-acetoxy-β-bromo-3-methoxyacetophenone 
• 284043-05-6 γ-O-(4-hydroxy-3-methoxyphenacetyl) t-butyl N-t-boc L-glutamate 
• 498-02-2 1-(3-methoxy-4-hydroxyphenyl)ethanone 
• 69638-06-8 α-bromo-3-methoxy-4-hydroxyacetophenone 

Downstream Products

• 139473-80-6 2-acetoxy-1-(4-hydroxy-3-methoxy-phenyl)-ethanone 
• 19767-93-2 α,4-diacetoxy-3-methoxyacetophenone 
• 37803-48-8 β-oxo-β-(3,4-dimethoxyphenyl)-ethanol 

Relevant academic research and scientific papers

Rapid flow-through fractionation of biomass to preserve labile aryl ether bonds in native lignin

Lignin is the second largest component of vascular plants and is the most abundant renewable aromatic polymer on our planet. The attractiveness of lignin valorization lies in its conversion into high value aromatic chemicals and biofuels through fractionation and upgrading. The literature has demonstrated that the presence of aryl ether bonds in native lignin was a key factor for the conversion, while the conventional technical lignins from carbohydrate-first processes, e.g. pulp and cellulose ethanol production, are intensively condensed and lack these linkages due to the intense delignification conditions. Here, by using the β-O-4 lignin model dimer GG, we reveal the dramatic degradation of GG and the synchronous formation of relatively stable intermediate β-O-4 dimers, C6C3 enol ether and the formylated enol ether, within the first 5 min under the conditions of 72 wt% aqueous formic acid and 130 °C, conditions suitable for biomass fractionation. Based on these findings, we propose a simple but effective strategy of rapid flow-through fractionation (RFF), which separates the dissolved lignin from the reactor in time and space, thereby preserving these labile aryl ether bonds in native lignin. The application of RFF of poplar wood with a short residence time of 2.6 min attained 75% delignification with an equivalent of the β-O-4 motif in native lignin. Structure-preserved lignins (β-O-4 retention, 75.0%-85.4%) were also harvested from wheat straw with good lignin yields (61.7%-78.5%). Contrarily, batch fractionation acted as a protracted war and resulted in extensive cleavage of aryl ether bonds as suggested by 92%-100% loss of the β-O-4 motif under the same conditions. Because of the well-preserved structure, RFF lignin can be used as a good feedstock to boost its downstream valorization, especially for hydrogenolysis into monophenolic chemicals and fuels. It is noteworthy that the carbohydrate fraction from RFF retained structural integrity and almost reached theoretical yields for glucan and xylan.

Synthesis and anti-inflammatory activity of isoquebecol

We report here the synthesis of isoquebecol, an unprecedented constitutional isomer of quebecol, a polyphenolic compound discovered in maple syrup. The methodology used to prepare isoquebecol involves, as key steps, the formation of a dibromoalkene from an α-ketoester precursor, followed by a double Suzuki-Miyaura reaction. The anti-inflammatory activity of isoquebecol was studied on macrophage cells by monitoring its ability to inhibit LPS-induced IL-6 secretion. Results show that this new compound has an improved bioactivity over that of its natural isomer. Precursors and derivatives of quebecol, isoquebecol and model analog 2,3,3-triphenylpropanol were also prepared and tested in this study. Comparison between the three series of compounds led to establishing new SARs concerning the aryl ring substitution pattern on the triarylpropanol scaffold and substructure functionalization.

METHOD FOR THE BREAKDOWN OF LIGNIN

The invention describes a method for the direct production of molecules with a minimum molecular weight of 78 g/mol by the breakdown of lignin, lignin derivatives, lignin fragments, and/or lignin-containing substances or mixtures in the presence of at least one polyoxometallate and preferably in the presence of a radical scavenger in a liquid medium.

Immobilized methyltrioxo rhenium (MTO)/H2O2 systems for the oxidation of lignin and lignin model compounds

A convenient and efficient application of heterogeneous methylrhenium trioxide (MTO) systems for the selective oxidation of lignin model compounds and lignins is reported. Environmental friendly and low-cost H2O2 was used as the oxygen atom donor. Overall, the data presented and discussed in this paper point toward the conclusion that the immobilized heterogeneous catalytic systems based on H2O2/and MTO catalysts are able to extensively oxidize both phenolic and non-phenolic, monomeric, and dimeric, lignin model compounds. Condensed diphenylmethane models were found also extensively oxidized. Technical lignins, such as hydrolytic sugar cane lignin (SCL) and red spruce kraft lignin (RSL), displayed oxidative activity with immobilized MTO catalytic systems. After oxidation, these lignins displayed the formation of more soluble lignin fragments with a high degree of degradation as indicated by the lower contents of aliphatic and condensed OH groups, and the higher amounts of carboxylic acid moieties. Our data indicate that immobilized MTO catalytic systems are significant potential candidates for the development of alternative totally chlorine-free delignification processes and environmental sustainable lignin selective modification reactions.

Methyltrioxorhenium: A new catalyst for the activation of hydrogen peroxide to the oxidation of lignin and lignin model compounds

The oxidative degradation of lignin under totally chlorine free conditions is one of the most relevant targets for the design of environmental friendly pulping and bleaching industrial processes. Methyltrioxorhenium was found a powerful and promising catalyst for the oxidation of both phenolic and non-phenolic lignin model compounds by use of hydrogen peroxide as primary oxidant. Three different technical lignins, hydrolytic sugar cane lignin (SCL), red spruce kraft lignin (RSL) and a hardwood organosolvent lignin (OSL), that are representative examples of widely diffused para-hydroxyphenyl-guaiacyl, guaiacyl and guaiacyl-syringyl lignins, were also extensively degraded under similar experimental conditions.

Enzyme catalyzed hydroxymethylation of aromatic aldehydes with formaldehyde. Synthesis of hydroxyacetophenones and (S)-benzoins

Benzaldehyde lyase from the Pseudomonas Fluorescens catalyzed reaction of aromatic aldehydes with formaldehyde providing 2-hydroxy-1-arylethan-1-one in high yields via an acyloin linkage. Kinetic resolution of rac-benzoins with formaldehyde providing (S)-benzoins and 2-hydroxy-1-arylethan-1-one via C-C bond cleavage and a bond formation reaction.

New Phototriggers: Extending the p-Hydroxyphenacyl π-π* Absorption Range

(Matrix Presented) Introducing 3-methoxy or 3,5-dimethoxy substituents on the 4-hydroxyphenacyl (pHP) photoremovable protecting group has been explored with two excitatory γ-amino acids, L-glutamic acid and γ-amino butyric acid (GABA). These substituents significantly extend the absorption range of the pHP chromophore, e.g., the tail of absorption bands of 2a,b extend above 400 nm, well beyond the absorptions of aromatic amino acids and nucleotides. Irradiation releases the amino acids with rate constants of ～107 s-1 and appearance efficiencies (Φapp) of 0.03-0.04. The photoproducts are formed through the pHP excited triplet and are primarily products of photoreduction and photohydrolysis. 1a,b also rearranged to the phenylacetic acid 3.