Search results for "Thiol"
showing 10 items of 485 documents
Preparation of 4-substituted 1,3-oxathiolan-5-onesviathe sulphenium ion intermediate generated by the pummerer rearrangement
1993
4-Substituted 1,3-oxathiolan-5-ones have been synthesized via the Pummerer rearrangement from the S-oxide of the parent molecule. The 4,5-dione is obtained in the presence of pyridine N-oxide.
Fluoreszierende und nicht fluoreszierende (Aryl)(vinyl)sulfone — Reagenzien zum Schutz und Nachweis von Thiolfunktionen
1985
Konkurrenzversuche und kinetisch verfolgte Umsetzungen geben Aufschlus uber die Geschwindigkeit der Addition von primaren, sekundaren und tertiaren Thiolen an die (Aryl)- bzw. (Alkyl)-(vinyl)sulfone 1 und 4 – 7. Die gebildeten saurestabilen 2-(Alkyl-/arylthio)ethylsulfone werden durch Basen in einer der Bildung analogen Geschwindigkeitsabstufung wieder in die Thiole und Vinylsulfone zerlegt. Eine kinetisch gesteuerte, selektive Einfuhrung und selektive Ablosung unterschiedlicher Arylsulfonylethyl-Schutzgruppen in dem gleichen Molekul ist damit moglich. – Die Verwendung fluoreszierender Vinylsulfone (5, 10 und 11) eroffnet der Analyse und Synthese neue Einsatzfelder. Die SH-selektiven Vinyls…
ARYL-VINYLSULFONE—REAGENTIEN ZUM SCHUTZ UND NACHWEIS VON THIOLFUNKTIONEN
1983
Abstract Aryl vinyl sulfones selectively react with thiol groups to acid-stable compounds which easily are cleaved by mild bases to thiol compounds. Ester and amide groups are not attacked under these conditions. Therefore, these compounds are good protecting groups or labels in peptide chemistry. The following aryl vinyl sulfones were investigated: phenyl vinyl sulfone 1, p-carbethoxyphenyl vinyl sulfone 15 and the fluorescent 5-dimethylaminonaphthyl 1-vinyl sulfone 5 and 5-methoxynaphthyl-1 vinyl sulfone 10. The last two compounds are very useful reagents for the quantitative determination of SH-groups in polypeptides such as enzymes. Aryl-vinylsulfone reagieren selektiv mit Thiolgruppen …
Spectroscopic behaviour of metal–drug complexes. Infrared spectra of Cu(II) complexes with 5-amino-1,3,4-thiadiazole-2-thiol (Hatm)
1997
Abstract The infrared spectra of the drug Hatm and its copper (II) complexes with stoichiometry [Cu(atm) 2 (H 2 O)] and [Cu(Hatm)(HIm) 2 (SO 4 )] are reported and discussed. The Raman spectrum of Hatm is also reported. An assignment of Hatm, HIm, H 2 O and SO 4 modes in the complexes is proposed in comparison with the modes of the free ligands. Important information about the metal–ligand vibrations has been obtained.
Synthesis and thermal decomposition studies of homo- and heteroleptic tin(iv) thiolates and dithiocarbamates: molecular precursors for tin sulfides
2002
The syntheses and X-ray structures of novel heteroleptic thiolate/dithiocarbamate derivatives (Et2NCS2)2(RS)2Sn (R = Cy, CH2CF3) have been examined and their thermal decompositions compared with those of selected tin(II) and tin(IV) dithiocarbamates. The heteroleptic species decompose to SnS by initial elimination of RSSR to afford (Et2NCS2)2Sn and subsequent loss of [Et2NC(S)]2S. In contrast, (Et2NCS2)4Sn decomposes via [(Et2NCS2)2SnS]2, whose structure has been determined, and finally to SnS2 by sequential elimination of [Et2NC(S)]2S. The two families of compounds, (R2NCS2)4Sn and (Et2NCS2)2(RS)2Sn, thus provide single-source materials for bulk SnS2 and SnS, respectively, by virtue of the…
A new type of pi-electron donors with one dithiole unit: Substituted 7-(1,3-dithiol-2-ylidene)-7-hydrobenz[d,e]anthracenes
1999
New electron donors 11a–c bearing only one 1,3-dithiole ring conjugated with an acene backbone have been synthesized by Wittig–Horner reactions from 7H-benz[d,e]anthracen-7-one (10) and differently substituted phosphonate esters 9a–c. The donor properties of 11 have been characterized by means of both experimental techniques and quantum chemical calculations. Cyclic voltammetry measurements on the novel compounds predict donor abilities comparable to those of TTF and BEDT-TTF. The voltammograms show a multi-stage redox behaviour with oxidation up to the trication, where the first two oxidation processes take place at very close potentials. These processes have been assigned to a simultaneou…
Synthesis and structural characterization of cis- and trans-fused 4a,5,6,7,8,8a-hexahydro-2H,4H-1,3-benzodithiines and their 2-methyl and 2,2-dimethy…
2002
Both cis- and trans-fused 4a,5,6,7,8,8a-hexahydro-2H,4H-1,3-benzodithiine together with their 2-methyl and 2,2-dimethyl derivatives were prepared as racemates from the appropriate dithiols obtained via multistep syntheses. The products were characterized by 1 H and 13 C NMR, mass spectrometry, and for two of the cis-fused compounds by X-ray diffraction. 1 H, 1 H vicinal coupling constants indicated that all compounds attain chair-chair conformations as their predominant conformations. All three trans-fused isomers exist in totally biased chair-chair conformations and are essentially conformationally locked, whereas the cis-fused compounds are conformationally mobile and can potentially atta…
CCDC 2153375: Experimental Crystal Structure Determination
2022
Related Article: María Vicent-Morales, María Esteve-Rochina, Joaquín Calbo, Enrique Ortí, Iñigo J. Vitórica-Yrezábal, Guillermo Mínguez Espallargas|2022|J.Am.Chem.Soc.|144|9074|doi:10.1021/jacs.2c01957
CCDC 1942682: Experimental Crystal Structure Determination
2019
Related Article: Xiting Yuan, Cunfa Sun, Xihua Li, Sami Malola, Boon K. Teo, Hannu Häkkinen, Lan-Sun Zheng, Nanfeng Zheng|2019|J.Am.Chem.Soc.|141|11905|doi:10.1021/jacs.9b03009
Genetic differentiation of three species of Matthiola (Brassicaceae) in the Sicilian insular system
2005
We examined the genetic variation of 12 isozyme loci in 14 populations of Matthiola (Brassicaceae) representing the geographic distribution of the species M. incana, M. fruticulosa ssp. fruticulosa and M. tricuspidata in the Sicilian insular system and the adjacent mainland areas to estimate the levels and apportionment of genetic variation in the insular populations and to understand their population dynamics. The disparity in the distribution of polymorphism in populations of M. incana ssp. incana (low within populations but with high values of F ST and G ST ) contrasts with the homogeneity in the inter-population distribution of the high genetic variation detected in M. tricuspidata and …