80-58-0Relevant articles and documents
O-to-S Substitution Enables Dovetailing Conflicting Cyclizability, Polymerizability, and Recyclability: Dithiolactone vs. Dilactone
Chen, Jinlong,Li, Maosheng,Tao, Youhua,Wang, Xianhong,Wang, Yanchao
supporting information, p. 22547 - 22553 (2021/09/09)
Developing chemically recyclable polymers represents a greener alternative to landfill and incineration and offers a closed-loop strategy toward a circular materials economy. However, the synthesis of chemically recyclable polymers is still plagued with certain fundamental limitations, including trade-offs between the monomer's cyclizability and polymerizability, as well as between polymer's depolymerizability and properties. Here we describe the subtle O-to-S substitution, dithiolactone monomers derived from abundant feedstock α-amino acids can demonstrate appealing chemical properties different from those of dilactone, including accelerated ring closure, augmented kinetics polymerizability, high depolymerizability and selectivity, and thus constitute a unique class of polythioester materials exhibiting controlled molecular weight (up to 100.5 kDa), atactic yet high crystallinity, structurally diversity, and chemical recyclability. These polythioesters well addresses the formidable challenges of developing chemically recyclable polymers by having an unusual set of desired properties, including easy-to-make monomer from ubiquitous feedstock, and high polymerizability, crystallinity and precise tunability of physicochemical performance, as well as high depolymerizability and selectivity. Computational studies explain why O-to-S modification of polymer backbone enables dovetailing desirable, but conflicting, performance into one polymer structure.
Method for preparing alpha-bromo fatty acid ester
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Paragraph 0020-0021; 0023-0024, (2019/04/04)
The invention provides a method for preparing alpha-bromo fatty acid ester. The method comprises the steps of bromination and esterification, wherein the bromination comprises the step of subjecting fatty acid and bromine to a bromination reaction in a manner of taking bromosuccinimide as a catalyst so as to produce alpha-bromo fatty acid, and the esterification comprises the step of subjecting the alpha-bromo fatty acid and lower alcohol to an esterification reaction in a manner of taking bisulfate as a catalyst, so as to produce the alpha-bromo fatty acid ester. According to the method provided by the invention, the bisulfate is used as the catalyst during esterification, so that combustible red phosphorus with strong feeding odors is avoided, and the whole reaction process is environmentally friendly and is free of equipment corrosion and a phenomenon of carbonization of part of the product; the catalyst can be recycled, and the yield is relatively high and can reach 98%.
Catalytic Asymmetric Conjugate Addition and Sulfenylation of Diarylthiazolidin-2,4-diones
Jiao, Lihui,Bu, Liwei,Ye, Xinyi,Zhao, Xiaowei,Jiang, Zhiyong
, p. 9620 - 9629 (2016/11/02)
This work reports the first application of diarylthiazolidin-2,4-diones as nucleophiles in asymmetric catalysis. By utilizing chiral amino acid-based (thio)urea-tertiary amines as the catalysts, we successively established asymmetric conjugate addition to nitroolefins and sulfenylation to N-(sulfanyl)-succinimides of diarylthiazolidin-2,4-diones. Two series of biologically important 5-aryl-5-substituted thiazolidin-2,4-diones were obtained with high enantio- and diastereoselectivities (up to >99% ee and >19:1 dr). The enantioenriched adducts were found to show satisfactory anticancer activities against three different cancer cell lines using the MTT assay. All of these successes depended on the development of a general and expedient synthetic strategy to provide diverse 5H-thiazolidin-2,4-diones.
