1713-85-5Relevant articles and documents
Synthesis of Tertiary Enamides by Ag2CO3-Promoted Pd-Catalyzed Alkenylation of Acyclic Secondary Amides
Delforge, Arnaud,Georgiou, Irene,Kremer, Adrian,Wouters, Johan,Bonifazi, Davide
, p. 4844 - 4847 (2016)
A Pd-catalyzed methodology for the preparation of tertiary enamides from acyclic secondary amides and bromo acrylates under mild reaction conditions has been developed using [Pd2(dba)3], XantPhos, and Ag2CO3 as a base. The reaction occurs through a stereospecific metal-mediated oxidative-insertion mechanism.
Demonstration of isospecific free radical polymerization of acrylate controlled by conformation and chirality of monomer
Tanaka, Hitoshi,Matsubara, Yoshitaka,Kusunoki, Katsuhiko,Saito, Naoki,Kibayashi, Tatsuya
, p. 2007 - 2016 (2015)
Radical polymerization of lactic acid-based chiral and achiral methylene dioxolanones, a model for conformationally s-cis locked acrylate, was carried out with AIBN to demonstrate an isospecific free radical polymerization controlled by chirality and conformation of monomer. Polymerization of the dioxolanones proceeded smoothly without ring opening to give a polymer with moderate molecular weight and 100% of maximum isotacticity. ESR spectrum indicated a twisted conformation of the growing poly(methylene dioxolanone) radical in contrast to an acyclic analogous radical, suggesting a restriction of the free rotation around main chain CαCβ bond of the growing radical center. Chirality as well as the polarity and bulkiness of monomer affected the polymer tacticity, and chiral alkyl substituent would afford a high isotactic polymer, in which higher the enantiomeric excess of the monomer was, higher the isotacticity of the polymer was. While, achiral or polar substituents including dibenzyl and trichloromethyl groups would afford an atactic polymer. In addition, glass transition temperature (Tg) of the resulting polymers was significantly high, ranging from 172.2 to 229.8°C, and even for an isotactic polymer Tg was as high as 206.8°C.
Synthesis of F-alkyl α-hydroxy acids and esters from F-alkyl epoxides and F-alkyl α-bromo acids and esters from F-alkyl bromohydrins
Ould Amanetoullah,Chaabouni,Baklouti
, p. 149 - 153 (1997)
F-alkyl α-hydroxy acids and F-alkyl α-bromo acids were prepared respectively by the nitric acid ring-opening oxidative reaction of F-alkyl oxiranes, and oxidation by chromic acid of F-alkyl bromohydrins. The synthesized acids were converted to the corresponding methyl esters which may prove to be useful in the synthesis of F-alkylated heterocycles.
Synthesis of an Alkene-Containing Copolylactide and Its Facile Modification by the Addition of Thiols
Kalelkar, Pranav P.,Alas, Guillermo R.,Collard, David M.
, p. 2609 - 2617 (2016)
The ring-opening copolymerization of 3,6-bis(chloromethyl)-1,4-dioxane-2,5-dione and l-lactide affords a chloro-substituted polylactide copolymer (chloro-PL). Base-promoted dehydrochlorination of chloro-PL provides a copolymer (ene-PL) that contains electrophilic α,β-unsaturated ester units. The copolymer undergoes conjugate addition with a variety of thiols in solution under mildly basic conditions and also in the presence of AIBN. Reaction on the surface of films of the unsaturated copolyester is demonstrated by the addition of a thiol-substituted fluorescent dye.
Chemical synthesis of membrane proteins: A model study on the influenza virus B proton channel
Baumruck,Tietze,Steinacker,Tietze
, p. 2365 - 2375 (2018/03/05)
In the present study we have developed and optimized a robust strategy for the synthesis of highly hydrophobic peptides, especially membrane proteins, exemplarily using the influenza B M2 proton channel (BM2(1-51)). This strategy is based on the native chemical ligation of two fragments, where the thioester fragment is formed from an oxo-ester peptide, which is synthesized using Fmoc-SPPS, and features an in situ cleavable solubilizing tag (ADO, ADO2 or ADO-Lys5). The nearly quantitative production of the ligation product was followed by an optimized work up protocol, resulting in almost quantitative desulfurization and Acm-group cleavage. Circular dichroism analysis in a POPC lipid membrane revealed that the synthetic BM2(1-51) construct adopts a helical structure similar to that of the previously characterized BM2(1-33).
3,6-dichloromethyl glycolide and preparation method and application thereof
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Paragraph 0012-0014, (2017/04/27)
The invention provides a monomer material 3,6-dichloromethyl glycolide which can be used for synthesizing biodegradable polyester. The 3,6-dichloromethyl glycolide is white crystals, the molecular formula of the 3,6-dichloromethyl glycolide is C6H6Cl2O4, and the molecular weight of the 3,6-dichloromethyl glycolide is 212. The synthetic route of the 3,6-dichloromethyl glycolide is that epoxy chloropropane or 3-chloro-1,2-propylene glycol is subjected to oxidation reaction and ring-closure reaction to prepare novel six-membered cyclic ester monomer, namely the 3,6-dichloromethyl glycolide. The 3,6-dichloromethyl glycolide can be used for synthesizing the biodegradable functional polyester; since a side chain of the 3,6-dichloromethyl glycolide contains methyl chloride, the 3,6-dichloromethyl glycolide can be used for preparing polyester, of which a side chain contains methyl chloride; and the 3,6-dichloromethyl glycolide can further react with a series of hydroxy and amino compounds to realize modification of physical, chemical and biological properties of the polyester. The 3,6-dichloromethyl glycolide has the advantages that the raw material is cheap and has wide sources, a preparation method is simple and the application value is high.
Synthesis of enantiomerically pure 3-aryloxy-2-hydroxypropanoic acids, intermediate products in the synthesis of cis-4-Aminochroman-3-ols
Bredikhina,Pashagin,Kurenkov,Bredikhin
, p. 535 - 539 (2014/06/10)
Oxidation of accessible (R)-3-chloropropane-1,2-diol to (R)-3-chloro-2-hydroxypropanoic acid and subsequent reaction of the latter with ortho-substituted sodium phenoxide gave a number of enantiomerically pure 3-aryloxy-2-hydroxypropanoic acid which are intermediate products in the synthesis of nonracemic 4-aminochroman-3-ols.
Enantioselective, chromatography-free synthesis of β3-Amino acids with natural and unnatural side chains
Gerfaud, Thibaud,Chiang, Ying-Ling,Kreituss, Imants,Russak, Justin A.,Bode, Jeffrey W.
experimental part, p. 687 - 696 (2012/07/13)
β3-Amino acids are key components of some pharmaceuticals, excellent surrogates for metabolically labile α-amino acids, and building blocks for chiral heterocycles. Unfortunately they are not easily accessible in enantiomerically pure form, especially when possessing unnatural side chains. A flexible, chromatography-free process for the synthesis of enantiopure β3-amino acids possessing natural and unnatural side chains is described. The procedure uses inexpensive starting materials and reagents and offers a good alternative to the hazardous and expensive Arndt-Eistert homologation of enantiopure α-amino acids. Its utility has been demonstrated with the preparative scale synthesis of two valuable β3-amino acids possessing unnatural side chains.
SYNTHESIS OF HYDROXY CARBOXYLIC ACIDS BY THE OXIDATION OF α-OLEFINS WITH CONCENTRATED NITRIC ACID
Tyurina, R. D.,Gorokhova, T. G.,Rusakova, M. S.,Ustavshchikov, B. F.
, p. 1070 - 1075 (2007/10/02)
The reaction of propene, 2-methylpropene, 3-chloro-1-propene, and 2-methyl-3-chloro-1-propene with concentrated nitric acid (initial weight fraction 98-91percent) leads to the corresponding α-hydroxy carboxylic acids. The key stage in the oxidation of the α-olefin to the hydroxy acid is its nitrosation, which is promoted by increase in the solvent polarity and in the nucleophilicity of the double bond in the olefin. The introduction of chlorine into the olefin molecule leads to some increase in the probability of nitration.
