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1.
Perfluorocarboxylic thioesters RFC(O)SR (RF=CF3(CF2)j, R=CH3(CH2)i, i andj=0–5) were studied for the first time by GLC on packed columns using SE-30, SKTFT-50X, and XE-60 as the stationary phase.
The values of thermodynamics functions of sorption were calculated. The correlations between these functions and the molecular
structures as well as the conditions of analysis were established. The insertion of the S atom into the molecules of derivatives
of perfluorocarboxylic acids causes a decrease in the contribution of the orientation interaction and an increase in the dispersion
interaction of thioesters with the stationary phases compared to esters and amides of perfluorocarboxylic acids studied previously.
For Part 1, see Ref. 1.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1165–1168, June, 1997. 相似文献
2.
Gas-liquid chromatography of thioesters of perfluorocarboxylic acids 1. Characteristics of retention
Retention of thioesters of perfluoropentanoic acid C4F9C(O)SR was studied by GLC on packed and capillary columns using stationary phases SE-30, SKTFT-50X, XE-60, and Carbowax 20M.
The retention indices of these compounds were calculated, and their relationship with the structure of the compounds and the
conditions of the analysis were established.
Translated fromIzvestiya Akademii, Nauk. Seriya Khimicheskaya, No. 5, pp. 984–986, May, 1997. 相似文献
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《Tetrahedron》2003,59(37):7331-7336
S-Alkyl and S-aryl thioesters react with nitriles in the presence of triflic anhydride to form substituted 4-alkylthio- and 4-arylthiopyrimidines. However, when methyl thiocyanate is used as nitrile, dithioimidocarbonates are formed. A mechanism to explain these differences is postulated. 相似文献
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Caroline LapeyreFlorence Bedos-Belval Hubert Duran Michel BaltasLiliane Gorrichon 《Tetrahedron letters》2003,44(12):2445-2447
The one-pot transesterification of diethylarylvinylphosphonates with N-acetylcysteamine has been achieved using phosphonochloridates as intermediates. Reaction of phosphonodiesters with (COCl)2 gave the corresponding chlorinated compounds, which were coupled with N-acetylcysteamine in presence of Et3N. 相似文献
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Akira Shigenaga 《Tetrahedron》2010,66(18):3290-377
The first facile Fmoc-based synthetic procedure for peptide thioacids was developed. Successful application of the resulting thioacids to sequential native chemical ligation (NCL) in the N to C direction was achieved. Conversion of the peptide thioacids to the corresponding thioesters with Ellman's reagent followed by NCL in the presence of tris(2-carboxyethyl)phosphine (TCEP) and thiophenol was accomplished in a one-pot manner. 相似文献
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Direct Catalytic Asymmetric Mannich Reaction with Dithiomalonates as Excellent Mannich Donors: Organocatalytic Synthesis of (R)‐Sitagliptin 下载免费PDF全文
Dr. Han Yong Bae Mun Jong Kim Jae Hun Sim Prof. Dr. Choong Eui Song 《Angewandte Chemie (International ed. in English)》2016,55(36):10825-10829
In this study, dithiomalonates (DTMs) were demonstrated to be exceptionally efficient Mannich donors in terms of reactivity and stereoselectivity in cinchona‐based‐squaramide‐catalyzed enantioselective Mannich reactions of diverse imines or α‐amidosulfones as imine surrogates. Owing to the superior reactivity of DTMs as compared to conventional malonates, the catalyst loading could be reduced to 0.1 mol % without the erosion of enantioselectivity (up to 99 % ee). Furthermore, by the use of a DTM, even some highly challenging primary alkyl α‐amidosulfones were smoothly converted into the desired adducts with excellent enantioselectivity (up to 97 % ee), whereas the use of a malonate or monothiomalonate resulted in no reaction under identical conditions. The synthetic utility of the chiral Mannich adducts obtained from primary alkyl substrates was highlighted by the organocatalytic, coupling‐reagent‐free synthesis of the antidiabetic drug (?)‐(R)‐sitagliptin. 相似文献
10.
David Crich Prof. Dr. Indrajeet Sharma 《Angewandte Chemie (International ed. in English)》2009,48(13):2355-2358
Highly activated thioesters formed by the rapid reaction of C‐terminal thioacids derived from protected amino acids and peptides with the Sanger reagent and other electron‐deficient aryl halides in the presence of a free amine immediately form a peptide bond with the amine. This essentially epimerization‐free method was used for the 4+4 block synthesis of a hindered octapeptide (see scheme; Boc, Pbf, and Trt are protecting groups).