80-58-0Relevant academic research and scientific papers
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
-
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%.
Reaction of Lithium Acylate α-Carbanions with Carbon Tetrabromide
Zorin,Zaynashev,Zorin
, p. 1527 - 1531 (2019/12/28)
Lithium acylate α-carbanions generated by metalation of acetic, butanoic, and 2-methylpropanoic acids with lithium diisopropylamide in THF under argon reacted with carbon tetrabromide at 20-25°C (2 h) to produce butanedioic acid or its 2,3-diethyl and 2,2,3,3-tetramethyl derivatives, as well as the corresponding 2-bromocarboxylic acids and bromoform. The effect of the halogen nature in carbon tetrahalide (CCl4, CBr4) on the reaction selectivity is discussed.
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.
Reactions of α-carbanions of lithium acylates with N,N-diethyl-N-chloro- and N,N-diethyl-N-bromoamines
Zorin,Zainashev,Zorin
, p. 2469 - 2472 (2016/12/24)
The interaction of α-carbanions of lithium acylates (prepared via metalation of acetic, butyric, or isobutyric acid with lithium diisopropylamide in tetrahydrofuran under argon atmosphere) with N,N-diethyl-N-chloro- or N,N-diethyl-N-bromoamine has resulte
Enoate reductase-mediated preparation of methyl (S)-2-bromobutanoate, a useful key intermediate for the synthesis of chiral active pharmaceutical ingredients
Brenna, Elisabetta,Gatti, Francesco G.,Manfredi, Alessia,Monti, Daniela,Parmeggiani, Fabio
experimental part, p. 262 - 268 (2012/06/18)
Enoate reductases belonging to the Old Yellow Enzyme (OYE) family were employed to develop a biocatalysed approach to methyl (S)-2-bromobutanoate, a key intermediate for the introduction of a particular stereogenic unit into the molecular skeleton of a certain class of chiral drugs. Methyl (Z)-2-bromocrotonate afforded, respectively, (S)-2-bromobutanoic acid (ee = 97%) and methyl (S)-2-bromobutanoate (ee = 97%) by baker's yeast fermentation and by OYE1-3 biotransformations. The bioreductions of other methyl 2-haloalkenoates were also considered. It was observed that the (Z)- and (E)-diastereoisomers of α-bromo unsaturated esters afforded the same enantiomer of the corresponding reduced product.
Discovery of a peroxisome proliferator activated receptor γ (PPARγ) modulator with balanced PPARα activity for the treatment of type 2 diabetes and dyslipidemia
Liu, Weiguo,Liu, Kun,Wood, Harold B.,McCann, Margaret E.,Doebber, Thomas W.,Chang, Ching H.,Akiyama, Taro E.,Einstein, Monica,Berger, Joel P.,Meinke, Peter T.
supporting information; experimental part, p. 4443 - 4453 (2010/03/02)
A series of 3-acylindole-1-benzylcarboxylic acids were designed and synthesized while searching for a PPARγ modulator with additional moderate intrinsic PPARα agonistic activity. 2-[3-[[3-(4-Chlorobenzoyl)-2-methyl- 6-(trifluoromethoxy)-1H-indol-1-yl]methyl]phenoxy]-(2R)-butanoic acid (12d) was identified as such an agent which demonstrated potent efficacy in lowering both glucose and lipids in multiple animal models with significantly attenuated side effects such as fluid retention and heart weight gain associated with PPARγ full agonists. The moderate PPARα activity of 12d not only contributed to the agent's ability to manage lipid profiles but also appears to have potentiated its PPARγ efficacy in lowering glucose levels in preclinical diabetic animal models.
Investigation of the synthetic and mechanistic aspects of the highly stereoselective transformation of α-thioamides to α-thio-β- chloroacrylamides
Murphy, Maureen,Lynch, Denis,Schaeffer, Marcel,Kissane, Marie,Chopra, Jay,O'Brien, Elisabeth,Ford, Alan,Ferguson, George,Maguire, Anita R.
, p. 1228 - 1241 (2008/02/03)
Treatment of a series of α-thioamides with N-chlorosuccinimide results in efficient transformation to the analogous α-thio-β- chloroacrylamides. The mechanistic pathway has been established through isolation and characterisation of intermediate compounds. The scope of the transformation has been explored - aryl and alkylthio substituents, primary, secondary and tertiary amides can be employed. In most instances, the chloroacrylamides are formed exclusively as the Z-stereoisomer; however, with tertiary propanamides or with amides derived from butanoic or pentanoic acid a mixture of E- and Z-stereoisomers is formed. The Royal Society of Chemistry.
A synthesis of levetiracetam based on (S)-N-phenylpantolactam as a chiral auxiliary
Boschi, Francesca,Camps, Pelayo,Comes-Franchini, Mauro,Munoz-Torrero, Diego,Ricci, Alfredo,Sanchez, Laura
, p. 3739 - 3745 (2007/10/03)
The synthesis of levetiracetam and its enantiomer by deracemization of (±)-2-bromobutyric acid using either (S)- or (R)-N-phenylpantolactam as chiral auxiliaries, followed by SN2 substitution of the bromine atom by a 2-oxopyrrolidin-1-yl group and amidation of the carboxylic acid, is described.
Mesoionic 5-alkyl-1,3-dithiolium-4-thiolates: Synthesis and brine shrimp toxicity
De Almeida, Paulo Afonso,Da Silva, Tania Maria Sarmento,Echevarria, Aurea
, p. 593 - 600 (2007/10/03)
A series of twelve 1,3-dithiolium-4-thiolate mesoionic compounds were synthesized and characterized. The synthetical approach starting from α-bromoalkanoic acids to obtain the corresponding 2-N-morpholino-dithiocarbamoyl-carboxylic acids that by on-pot reaction with carbon disulfide and acetic anhydride in triethylamine formed not isolate intermediates, 1,3-dithiolium-4-olates. After, the 2-N-morpholino-5-alkyl-1,3-dithiolium-4-thiolates were obtained by retro 1,3-dipolar addition reactions. The alkyl moiety linked to C-5 of heterocyclic ring permitted the increase of the hydrophobic character and this effect was evaluated on Artemia salina lethality. The results indicated a bell-shaped relationship between the number of carbon of side chain in mesoionic derivatives and LD50 in brine shrimp toxicity assays.
