58046-03-0

Upstream product

• 64-18-6 formic acid 
• 7382-59-4 guaiacylglycerol-β-guaiacyl ether 
• 15267-83-1 ethyl 2-(2,6-dimethoxyphenoxy)acetate 
• 2426-87-1 3-methoxy-4-(phenylmethoxy)benzaldehyde 

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.

Cleaving the β-O-4 bonds of lignin model compounds in an acidic ionic liquid, 1-H-3-methylimidazolium chloride: An optional strategy for the degradation of lignin

The hydrolysis of β-O-4 bonds in two lignin model compounds was studied in an acidic ionic liquid, 1-H-3-methylimidazolium chloride. The β-O-4 bonds of both guaiacylglycerol-β-guaiacyl ether and veratrylglycerol-β-guaiacyl ether underwent catalytic hydrolysis to produce guaiacol as the primary product with more than 70% yield at 150°C. Up to 32% substrate concentration could be treated in the system without a decrease in guaiacol production. The ionic liquid could be reused without loss of activity in guaiacol production from both guaiacylglycerol-β-guaiacyl ether and veratrylglycerol-β-guaiacyl ether. A possible mechanism accounting for the guaiacol production is presented.

METHOD OF SELECTIVELY OXIDIZING LIGNIN

A method of selectively reacting lignin or a lignin-derived reactant to yield an aromatic product. The method includes the step of reacting lignin or a lignin-derived reactant with a molybdenum-containing catalyst, in a solvent, and optionally in the presence of an oxidant, for a time and a temperature wherein at least a portion of the lignin or lignin-derived reactant is selectively converted into an aromatic product, preferably coniferaldehyde and/or sinapaldehyde.

Cross-coupling of hydroxycinnamyl aldehydes into lignins

(equation presented) Pathways for hydroxycinnamyl aldehyde incorporation into lignins are revealed by examining transgenic plants deficient in cinnamyl alcohol dehydrogenase, the enzyme that converts hydroxycinnamyl aldehydes to the hydroxycinnamyl alcoho