- H2-Free Re-Based Catalytic Dehydroxylation of Aldaric Acid to Muconic and Adipic Acid Esters
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As one of the most demanded dicarboxylic acids, adipic acid can be directly produced from renewable sources. Hexoses from (hemi)cellulose are oxidized to aldaric acids and subsequently catalytically dehydroxylated. Hitherto performed homogeneously, we present the first heterogeneous catalytic process for converting an aldaric acid into muconic and adipic acid. The contribution of leached Re from the solid pre-reduced catalyst was also investigated with hot-filtration test and found to be inactive for dehydroxylation. Corrosive or hazardous (HBr/H2) reagents are avoided and simple alcohols and solid Re/C catalysts in an inert atmosphere are used. At 120 °C, the carboxylic groups are protected by esterification, which prevents lactonization in the absence of water or acidic sites. Dehydroxylation and partial hydrogenation yield monohexenoates (93 %). For complete hydrogenation to adipate, a 16 % higher activation barrier necessitates higher temperatures.
- Ho?evar, Brigita,Pra?nikar, An?e,Hu?, Matej,Grilc, Miha,Likozar, Bla?
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supporting information
p. 1244 - 1253
(2020/12/09)
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- ELASTOMER COMPOSITIONS COMPRISING AN ADDUCT BETWEEN AN SP2 HYBRIDIZED CARBON ALLOTROPE AND A DICARBOXYLIC ACID DERIVATIVE
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The present invention relates to elastomer compositions comprising adducts between compounds of formula (I) preferably derived from natural sources such as mucic, pyromucic, glucaric, glycaric, galactaric, muconic acid and/or linear derivatives thereof containing ester or amide groups and/or cyclic derivatives thereof with heteroatoms in the ring, such as oxygen or nitrogen, and carbon allotropes in which the carbon is sp2 hybridized, such as for example carbon nanotubes, graphene or nanographites, carbon black.
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Page/Page column 43-44
(2020/11/12)
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- CHEMICAL PROCESS TO CONVERT MUCIC ACID TO ADIPIC ACID
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The present invention provides a method of synthesizing an ester of a saturated carboxylic acid from a saturated polyhydroxycarboxylic acid by performing a deoxydehydration reaction and a hydrogen transfer reaction.
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Page/Page column 15; 16
(2015/06/18)
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- Highly efficient chemical process to convert mucic acid into adipic acid and DFT studies of the mechanism of the rhenium-catalyzed deoxydehydration
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The production of bulk chemicals and fuels from renewable bio-based feedstocks is of significant importance for the sustainability of human society. Adipic acid, as one of the most-demanded drop-in chemicals from a bioresource, is used primarily for the large-volume production of nylon-6,6 polyamide. It is highly desirable to develop sustainable and environmentally friendly processes for the production of adipic acid from renewable feedstocks. However, currently there is no suitable bio-adipic acid synthesis process. Demonstrated herein is the highly efficient synthetic protocol for the conversion of mucic acid into adipic acid through the oxorhenium-complex-catalyzed deoxydehydration (DODH) reaction and subsequent Pt/C-catalyzed transfer hydrogenation. Quantitative yields (99 %) were achieved for the conversion of mucic acid into muconic acid and adipic acid either in separate sequences or in a one-step process. Taking a dip: A highly efficient synthetic protocol has been developed for the conversion of mucic acid into adipic acid by the oxorhenium-complex-catalyzed deoxydehydration reaction and subsequent Pt/C-catalyzed transfer hydrogenation. Quantitative yields were achieved for the conversion of mucic acid into muconic acid and adipic acid esters either through separate sequences or through a one-pot process.
- Li, Xiukai,Wu, Di,Lu, Ting,Yi, Guangshun,Su, Haibin,Zhang, Yugen
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supporting information
p. 4200 - 4204
(2014/05/06)
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