3588-17-8Relevant articles and documents
Molecular design and polymer structure control based on polymer crystal engineering. Topochemical polymerization of 1,3-diene mono- and dicarboxylic acid derivatives bearing a naphthylmethylammonium group as the countercation
Matsumoto, Akikazu,Nagahama, Sadamu,Odani, Toru
, p. 9109 - 9119 (2000)
The topochemical polymerization of the alkylammonium salts of (Z,Z)-, (E,Z)-, and (E,E)-1,3-diene mono- or dicarboxylic acids, i.e., of the muconic and sorbic acid derivatives, is described from the viewpoint of polymer crystal engineering. Not only the (Z,Z)- but also the (E,E)-derivatives polymerize to give a high molecular weight polymer in the crystalline state under UV irradiation when a naphthylmethylammonium moiety is introduced to these monomers as the countercation. NMR spectroscopy confirms the formation of the stereoregular meso- or erythro-diisotactic-trans-2,5-polymer during the polymerization, irrespective of the configuration of the monomers and the structure of the substituents. The single-crystal structure analysis of the naphthylmethylammonium salt of sorbic acid reveals the stacking of the diene moieties in the columns formed in the crystals, favorable for the topochemical polymerization. The photopolymerization reactivity and the stereochemistry of the resulting polymers are determined by the molecular packing in the crystals during the topochemical polymerization of the diene monomers.
Muconic acid production from methane using rationally-engineered methanotrophic biocatalysts
Henard, Calvin A.,Akberdin, Ilya R.,Kalyuzhnaya, Marina G.,Guarnieri, Michael T.
, p. 6731 - 6737 (2019)
Here, we demonstrate bioconversion of methane to muconic acid, a dicarboxylic acid that can be upgraded to an array of platform chemicals, by three gammaproteobacterial methanotrophs. All engineered methanotrophs expressing a heterologous dihydroxyshikimate dehydratase, protocatechuate decarboxylase, and catechol dioxygenase produced muconic acid from methane, with the highest titer (12.4 mg MA per L), yield (2.8 mg MA per g CH4), and specific productivity (1.2 mg MA per g dcw, 48 hr) synthesized by Methylotuvimicrobium buryatense, Methylococcus capsulatus, and Methylotuvimicrobium alcaliphilium, respectively. Methylotuvimicrobium alcaliphilum genome-scale model-guided strain engineering predicted that disruption of the pyruvate dehydrogenase or shikimate dehydrogenase would significantly enhance flux to the heterologous muconic acid pathway in this organism. However, knock-out of these targets caused a growth defect, and coupled with similar muconic acid titers (～1 mg L-1), resulted in minimal flux enhancement to muconic acid in these genetically-modified strains. The shikimate dehydrogenase mutant's ability to grow without aromatic amino acid supplementation revealed that M. alcaliphilum likely encodes an unidentified enzyme or pathway with shikimate biosynthetic capacity, which prevents maximal flux through the synthetic muconic acid pathway. This study expands the suite of products that can be generated from methane using methanotrophic biocatalysts, lays the foundation for green production of muconic acid-derived polymers from methane, and highlights the need for further analysis of methanotroph biosynthetic potential to guide refinement of metabolic models and strain engineering.
N,N,O-Coordinated tricarbonylrhenium precatalysts for the aerobic deoxydehydration of diols and polyols
Klein Gebbink, Robertus J. M.,Li, Jing,Lutz, Martin
, p. 3782 - 3788 (2020/06/22)
Rhenium complexes are well known catalysts for the deoxydehydration (DODH) of vicinal diols (glycols). In this work, we report on the DODH of diols and biomass-derived polyols using L4Re(CO)3as precatalyst (L4Re(CO)3= tricarbonylrhenium 2,4-di-tert-butyl-6-(((2-(dimethylamino)ethyl)(methyl)amino)methyl)phenolate). The DODH reaction was optimized using 2 mol% of L4Re(CO)3as precatalyst and 3-octanol as both reductant and solvent under aerobic conditions, generating the active high-valent rhenium speciesin situ. Both diol and biomass-based polyol substrates could be applied in this system to form the corresponding olefins with moderate to high yield. Typical features of this aerobic DODH system include a low tendency for the isomerization of aliphatic external olefin products to internal olefins, a high butadiene selectivity in the DODH of erythritol, the preferential formation of 2-vinylfuran from sugar substrates, and an overall low precatalyst loading. Several of these features indicate the formation of an active species that is different from the species formed in DODH by rhenium-trioxo catalysts. Overall, the bench-top stable and synthetically easily accessible, low-valent NNO-rhenium complex L4Re(CO)3represents an interesting alternative to high-valent rhenium catalysts in DODH chemistry.
Preparation method of gamma-substituted hexadienoic acid
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Paragraph 0018; 0021-0022; 0025-0028, (2021/01/20)
The invention relates to a preparation method of gamma-substituted hexadienoic acid. The method is characterized by comprising the following steps: (1) at -10-40 DEG C, adding a solvent, a catalyst and a catalytic assistant into a reaction vessel, stirring, introducing oxygen, adding 1-(2-furyl)-1-alkyl methanol, controlling the molar ratio of the catalyst to the catalytic assistant to the 1-(2-furyl)-1-alkyl methanol at 0.0001-5:0.0001-3:100, reacting at 0-200 DEG C under 0.1-20 MPa for 1-74 h, wherein the solvent is a mixed solution composed of a water phase and an organic phase according toa volume ratio of 1:0.01-3, the water phase is a phosphate acidic solution, the organic phase is a reaction inert solvent, the catalyst is a palladium compound, and the catalytic assistant is an amine or phosphine compound; and (2) cooling the reaction vessel to room temperature, adding an organic solvent, extracting, and carrying out reduced pressure distillation on the organic phase. The methodhas the advantages that the defect of technical economy in an existing synthesis route is overcome, the technological process is simplified, consumption and emission are reduced, energy consumption and cost are reduced, and the method is suitable for industrial production for increasing productivity.
