120-61-6Relevant articles and documents
One-pot formal synthesis of biorenewable terephthalic acid from methyl coumalate and methyl pyruvate
Lee, Jennifer J.,Kraus, George A.
, p. 2111 - 2116 (2014)
Diverse functionalized aromatic compounds are constructed from captodative dienophiles with exclusive regioselectivity. 100% biorenewable dimethyl terephthalate (DMT) from methyl coumalate and methyl pyruvate is achieved in a one-pot, Diels-Alder/decarboxylation/elimination sequence in nearly quantitative yield. The DMT system is solvent-free and purification is accomplished through recrystallization. DMT hydrolysis reveals the co-monomer terephthalic acid (TPA) as a bio-based drop-in replacement for the polymer industry, avoiding harsh oxidation and petrochemicals. the Partner Organisations 2014.
Kovacic,Kyriakis
, p. 454 (1963)
Bioderived Muconates by Cross-Metathesis and Their Conversion into Terephthalates
Sara?i, Erisa,Wang, Lan,Theopold, Klaus H.,Lobo, Raul F.
, p. 773 - 780 (2018)
Polyethylene terephthalate that is 100 % bioderived is in high demand in the market guided by the ever-more exigent sustainability regulations with the challenge of producing renewable terephthalic acid remaining. Renewable terephthalic acid or its precursors can be obtained by Diels–Alder cycloaddition and further dehydrogenation of biomass-derived muconic acid. The cis,cis isomer of the dicarboxylic acid is typically synthesized by fermentation with genetically modified microorganisms, a process that requires complex separations to obtain a high yield of the pure product. Furthermore, the cis isomer has to be transformed into the trans,trans form and has to be esterified before it is suitable for terephthalate synthesis. To overcome these challenges, we investigated the synthesis of dialkyl muconates by cross-metathesis. The Ru-catalyzed cross-coupling of sorbates with acrylates, which can be bioderived, proceeded selectively to yield diester muconates in up to 41 % yield by using very low catalyst amounts (0.5–3.0 mol %) and no solvent. In the optimized procedure, the muconate precipitated as a solid and was easily recovered from the reaction medium. Analysis by GC–MS and NMR spectroscopy showed that this method delivered exclusively the trans,trans isomer of dimethyl muconate. The Diels–Alder reaction of dimethyl muconate with ethylene was studied in various solvents to obtain 1,4-bis(carbomethoxy)cyclohexene. The cycloaddition proceeded with very high conversions (77–100 %) and yields (70–98 %) in all of the solvents investigated, and methanol and tetrahydrofuran were the best choices. Next, the aromatization of 1,4-bis(carbomethoxy)cyclohexene to dimethyl terephthalate over a Pd/C catalyst resulted in up to 70 % yield in tetrahydrofuran under an air atmosphere. Owing to the high yield of the reaction of dimethyl muconate to 1,4-bis(carbomethoxy)cyclohexene, no separation step was needed before the aromatization. This is the first time that cross-metathesis is used to produce bioderived trans,trans-muconates as precursors to renewable terephthalates, important building blocks in the polymer industry.
Design, synthesis and evaluation of cholinesterase hybrid inhibitors using a natural steroidal alkaloid as precursor
Borioni, José L.,Cavallaro, Valeria,Murray, Ana P.,Pe?é?ory, Alicia B.,Puiatti, Marcelo,García, Manuela E.
, (2021)
To date, Alzheimer's disease is the most alarming neurodegenerative disorder worldwide. This illness is multifactorial in nature and cholinesterase inhibitors have been the ones used in clinical treatments. In this context, many of these drugs selectively inhibit the acetylcholinesterase enzyme interacting in both the active site and the peripheric anionic site. Besides, some agents have exhibited extensive benefits being able to co-inhibit butyrylcholinesterase. In this contribution, a strategy previously explored by numerous authors is reported; the synthesis of hybrid cholinesterase inhibitors. This strategy uses a molecule of recognized high inhibitory activity (tacrine) together with a steroidal alkaloid of natural origin using different connectors. The biological assays demonstrated the improvement in the inhibitory activity compared to the alkaloidal precursor, together with the reinforcement of the interactions in multiple sites of the enzymatic cavity. This strategy should be explored and exploited in this area. Docking and molecular dynamic studies were performed to explain enzyme-ligand interactions, assisting a structure–activity relationship analysis.
Preparation of monoalkyl terephthalates: An overview
Chenot, Elodie-Denise,Bernardi, Dan,Comel, Alain,Kirsch, Gilbert
, p. 483 - 490 (2007)
Terephthalic acid can be readily converted to the corresponding monoalkyl terephthalate in high yield, via a two-step procedure. This method is advantageously compared to the more representative methods described in the literature. The purification of the expected monoester, a crucial problem for this synthetic pathway, is discussed, and an original procedure has been developed. Copyright Taylor & Francis Group, LLC.
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Reed,J.A. et al.
, p. 2188 - 2192 (1969)
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Chelate-Assisted, Pd-Catalyzed Efficient Carbonylation of Aryl Chlorides
Ben-David, Yehoshua,Portnoy, Moshe,Milstein, David
, p. 8742 - 8744 (1989)
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Oxidative esterification of benzaldehyde and deactivated aromatic aldehydes with N-bromosuccinimide-pyridine
Agrawal, Manoj K.,Adimurthy, Subbarayappa,Ghosh, Pushpito K.
, p. 2931 - 2936 (2012)
(Chemical Equation Presented) Whereas the oxidative esterification of benzaldehyde to methyl benzoate with N-bromosuccinimide (NBS)-pyridine requires dark conditions and 5 equivalents each of NBS and K2CO3 and gave only moderate yield (52%) of the product (McDonald et al. J. Org. Chem. 1989, 54, 1213), simple change of base to pyridine gave the desired product in 83% gas chromatographic yield with only 1 equivalent each of NBS and pyridine. Moreover, the reaction could be conducted without exclusion of light. Aromatic aldehydes bearing electron-withdrawing substituents at meta/para position yielded the corresponding methyl esters in still better yields. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications to view the free supplemental file. Copyright Taylor & Francis Group, LLC.
From alkyl aromatics to aromatic esters: Efficient and selective C-H activation promoted by a bimetallic heterogeneous catalyst
Liu, Hongli,Chen, Gongzhou,Jiang, Huanfeng,Li, Yingwei,Luque, Rafael
, p. 1892 - 1896 (2012)
Oxidizing aromatics: We report an operationally simple and green catalytic oxidative esterification approach that selectively converts methyl aromatics to aromatic carboxylates utilizing a highly stable, active, and reusable heterogeneous bimetallic Au-Pd catalyst and molecular oxygen as benign oxidant without requiring any additives.
Pd/C-Catalyzed methoxycarbonylation of aryl chlorides
Ai, Han-Jun,Franke, Robert,Wu, Xiao-Feng
, (2020)
A new protocol for the methoxycarbonylation of aryl chlorides has been developed. Various methyl benzoates were produced in good to excellent yields. Several parameters are crucial for the success of this procedure: 1) the usage of LiOMe as the base or co-nucleophile which facilitate the carbonylative transformation; 2) employing Pd/C as the catalyst to prevent the palladium reduced by MeOH and subsequent agglomerate; 3) CO concentration, excessive CO concentration will directly lead to the termination of the reaction.
FLOW CHEMISTRY SYNTHESIS OF ISOCYANATES
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Paragraph 0175; 0186-0187; 0228; 0230-0231, (2021/06/22)
The disclosure provides, inter alia, safe and environmentally-friendly methods, such as flow chemistry, to synthesize isocyanates, such as methylene diphenyl diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and tetramethylxylene diisocyanate.
Capturing ethylene glycol with dimethyl carbonate towards depolymerisation of polyethylene terephthalate at ambient temperature
Nakajima, Yumiko,Sato, Junichi,Tanaka, Shinji
supporting information, p. 9412 - 9416 (2021/12/09)
Depolymerisation of polyethylene terephthalate (PET) via alkali metal alkoxide catalysed methanolysis efficiently proceeded at ambient temperature by capturing ethylene glycol (EG) with dimethyl carbonate (DMC), which biased the equilibrium toward dimethy
