3645-00-9Relevant academic research and scientific papers
Synthesis and characterization of polyethylene terephthalate (PET) precursors and potential degradation products: Toxicity study and application in discovery of novel PETases
Djapovic, Milica,Milivojevic, Dusan,Ilic-Tomic, Tatjana,Lje?evi?, Marija,Nikolaivits, Efstratios,Topakas, Evangelos,Maslak, Veselin,Nikodinovic-Runic, Jasmina
supporting information, (2021/03/01)
Polyethylene terephthalate (PET) is widely used material and as such became highly enriched in nature. It is generally considered inert and safe plastic, but due to the recent increased efforts to break-down PET using biotechnological approaches, we realized the scarcity of information about structural analysis of possible degradation products and their ecotoxicological assessment. Therefore, in this study, 11 compounds belonging to the group of PET precursors and possible degradation products have been comprehensively characterized. Seven of these compounds including 1-(2-hydroxyethyl)-4-methylterephthalate, ethylene glycol bis(methyl terephthalate), methyl bis(2-hydroxyethyl terephtahalate), 1,4-benzenedicarboxylic acid, 1,4-bis[2-[[4-(methoxycarbonyl)benzoyl]oxy]ethyl] ester and methyl tris(2-hydroxyethyl terephthalate) corresponding to mono-, 1.5-, di-, 2,5- and trimer of PET were synthetized and structurally characterized for the first time. In-silico druglikeness and physico-chemical properties of these compounds were predicted using variety of platforms. No antimicrobial properties were detected even at 1000 μg/mL. Ecotoxicological impact of the compounds against marine bacteria Allivibrio fischeri proved that the 6 out of 11 tested PET-associated compounds may be classified as harmful to aquatic microorganisms, with PET trimer being one of the most toxic. In comparison, most of the compounds were not toxic on human lung fibroblasts (MRC-5) at 200 μg/mL with inhibiting concentration (IC50) values of 30 μg/mL and 50 μg/mL determined for PET dimer and trimer. Only three of these compounds including PET monomer were toxic to nematode Caenorhabditis elegans at high concentration of 500 μg/mL. In terms of the applicative potential, PET dimer can be used as suitable substrate for the screening, identification and characterization of novel PET-depolymerizing enzymes.
Electrochemical esterification reaction of alkynes with diols: Via cleavage of carbon-carbon triple bonds without catalyst and oxidant
Cheng, Hui-Hui,Gao, Hui,Li, Pin-Hua,Shen, Hui-Zhi,Wang, Pei-Long
supporting information, p. 6783 - 6791 (2020/11/09)
A novel electrochemical esterification of alkynes for the synthesis of esters was developed in which diols and their derivatives were used as the partners. This method is green as it is catalyst-free, oxidant-free, and additive-free and shows atom-economy. This is the first example of an electrochemical reaction via cleavage of carbon-carbon triple bonds. Meanwhile, this is also the first example of a carbon-carbon triple bond cleavage reaction of alkynes with diols. This journal is
Palladium on Carbon-Catalyzed Chemoselective Oxygen Oxidation of Aromatic Acetals
Yasukawa, Naoki,Asai, Shota,Kato, Maho,Monguchi, Yasunari,Sajiki, Hironao,Sawama, Yoshinari
, p. 5604 - 5607 (2016/11/17)
The development of an unprecedented chemoselective transformation has contributed to forming a novel synthetic process for target molecules. Chemoselective oxidation of aromatic acetals has been accomplished using a reusable palladium on carbon catalyst under atmospheric oxygen conditions to form ester derivatives with tolerance of aliphatic acetals and ketals.
Facile and efficient synthesis of hydroxyalkyl esters from cyclic acetals through aerobic photo-oxidation using anthraquinone-2-carboxylic acid
Yamaguchi, Tomoaki,Kudo, Yasuhisa,Hirashima, Shin-ichi,Yamaguchi, Eiji,Tada, Norihiro,Miura, Tsuyoshi,Itoh, Akichika
, p. 1973 - 1975 (2015/03/18)
Abstract A convenient metal-free oxidation protocol of various cyclic acetals with molecular oxygen and anthraquinone-2-carboxylic acid under visible light irradiation by a fluorescent lamp afforded their corresponding hydroxyalkyl esters.
METHODS OF DEPOLYMERIZING TEREPHTHALATE POLYESTERS
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Page/Page column 15, (2012/09/11)
A method comprises forming a reaction mixture comprising a terephthalate polyester, a glycol comprising 2 to 5 carbons, and an amidine organocatalyst; and heating the reaction mixture at a temperature of about 120° C. or more to depolymerize the terephthalate polyester, thereby forming a terephthalate reaction product comprising a monomeric dihydroxy terephthalate diester; wherein the terephthalate reaction product contains terephthalate oligomers in an amount less than the amount of terephthalate oligomers that would result from i) substituting the amidine organocatalyst with an equimolar amount of a guanidine catalyst and ii) depolymerizing the terephthalate polyester under otherwise identical reaction conditions.
CATALYTIC PROPERTIES OF ACETYLACETONATES OF CERTAIN METALS IN THE TRANSESTERIFICATION REACTION
YAMPOL'SKAYA MA,ABLOV AV,DAVYDOVA SL,PLATE NA
, p. 1142 - 1144 (2007/10/05)
The kinetics of the transesterification of dimethyl terephthalate and dimethyl azelate by ethylene glycol, catalyzed by acetylacetonates of An(II), Cd(II), Mn(III), and Cu(II), as well as their macromolecular analogs, was investigated. The nature of the dependence of the rate constant of transesterification on the concentration of the diester, as well as the correspondence of the catalytic activity of the acetylacetonates to the order of their stability, indicate the formation of an intermediate catalyst- substrate complex by coordination of a molecule of the diester by the metallic atom of the catalyst.
