Search results for "Trifluoroacetic Acid"
showing 10 items of 34 documents
Selective Preparation of Diamondoid Phosphonates
2014
We present an effective sequence for the preparation of phosphonic acid derivatives of the diamondoids diamantane, triamantane, [121]tetramantane, and [1(2,3)4]pentamantane. The reactions of the corresponding diamondoid hydroxy derivatives with PCl3 in sulfuric or trifluoroacetic acid give mono- as well as didichlorophosphorylated diamondoids in high preparative yields.
PLA2-mediated catalytic activation of its inhibitor 25-acetyl-petrosaspongiolide M: serendipitous identification of a new PLA2 suicide inhibitor.
2004
Abstract25-Acetyl-petrosaspongiolide M (PMAc) (1), a mild non-covalent PLA2 inhibitor, unexpectedly recovers, after incubation with bvPLA2, the ability to covalently modify the enzyme target. This study demonstrates the catalytic effect of bvPLA2 in converting 1 in its deacetylated congener petrosaspongiolide M (PM) (2), a strong covalent PLA2 inhibitor whose molecular mechanism of inhibition has already been clarified. Moreover, our findings outline the potential role of PMAc as anti-inflammatory pro-drug, by virtue of its ability of delivering the active PM agent at the site of inflammation, functioning as a suicide inhibitor.
CCDC 2042388: Experimental Crystal Structure Determination
2021
Related Article: Saeb Aliwaini, Bassam Abu Thaher, Ihab Al-Masri, Nabil Shurrab, Said El-Kurdi, Dieter Schollmeyer, Basem Qeshta, Mariam Ghunaim, Ren�� Csuk, Stefan Laufer, Lars Kaiser, Hans-Peter Deigner|2021|Molecules|26|4065|doi:10.3390/molecules26134065
CCDC 1537660: Experimental Crystal Structure Determination
2017
Related Article: Georges Mouchaham, Nans Roques, Walid Khodja, Carine Duhayon, Yannick Coppel, Stéphane Brandès, Tamás Fodor, Michel Meyer and Jean-Pascal Sutter|2017|Chem.-Eur.J.|23|11818|doi:10.1002/chem.201701732
CCDC 916484: Experimental Crystal Structure Determination
2013
Related Article: Konrad Herbst, Mercedes Sanaú, Francisco Estevan, M. Angeles Úbeda|2013|J.Organomet.Chem.|733|53|doi:10.1016/j.jorganchem.2013.02.030
CCDC 1437950: Experimental Crystal Structure Determination
2016
Related Article: Prasit Kumar Sahoo, Chandan Giri, Tuhin Subhra Haldar, Rakesh Puttreddy, Kari Rissanen and Prasenjit Mal|2016|Eur.J.Inorg.Chem.||1283|doi:10.1002/ejoc.201600005
Simultaneous substitution of bridging acetate groups and reversible RhC bond cleavage in [Rh2(O2CCH3)3-{(C6H4)PPh2}(HO2CCH3)2] in the presence of CF…
1993
Abstract The reaction of the monometallated compound [Rh2(O2CCH3)3 {(C6H4)PPh2}(HO2CCH3)2] (1) with CF3CO2H at room temperature yields [Rh2(O2CCF3)3{(C6H4)PPh2}(HO2CCF3)2] (3) as the only isolable product. Compound 3 has been characterized by X-ray methods. 3 crystallizes in the space group P21 / n. It contains three trifluoroacetate groups bridging a Rh4+2 unit with a RhRh bond distance of 2.438(1) Ă; the fourth bridging ligand is a triphenylphosphine metallated at one of the ortho positions. Two molecules of trifluoroacetic acid occupy the axial coordination positions. In addition to the substitution of acetate groups, reversible electrophilic RhC bond activation is observed.
Fluorenylmethoxycarbonyl-N-methylamino Acids Synthesized in a Flow Tube-in-Tube Reactor with a Liquid-Liquid Semipermeable Membrane
2013
Both steps of the N-methylation of 9-fluorenylmethoxycarbonyl (Fmoc) amino acids were carried out in a microstructured tube-in-tube reactor equipped with a semipermeable Teflon® AF 2400 membrane as the inner tubing. In the first step, gaseous formaldehyde was passed through the inner membrane to effect the acid-catalyzed conversion of the Fmoc amino acids into the corresponding N-Fmoc oxazolidinones. In the second step, liquid–liquid transfer of trifluoroacetic acid was used for the first time in such a reactor for the reductive opening of these oxazolidinones to give Fmoc N-methylamino acids in high yields.
Elucidation of structure and microheterogeneity of the polypeptide antibiotics paracelsin and trichotoxin A-50 by fast atom bombardment mass spectrom…
1984
Specific and sensitive procedures have been developed which enabled the structure elucidation of the polypeptide antibiotics (peptaibols), paracelsin isolated from Trichoderma reesei, and of trichotoxin A-50 from Trichoderma viride, by fast atom bombardment and field desorption mass spectrometry. Both peptides were found to exhibit a pronounced microheterogeneity by single and multiple exchange of amino acids. Separation by analytical and semipreparative high-performance liquid chromatography (HPLC) on octadecylsilyl-bonded, reversed-phase columns afforded a series of sequence analogues for each polypeptide. Unequivocal molecular weight and sequence identifications were obtained by positive…
Separation of Proteic Primary Amino Acids under Several Reversed‐Phase Liquid Chromatographic Conditions
2006
Abstract The reversed‐phase liquid chromatographic (RPLC) analysis of proteic primary amino acids with acetonitrile‐water, using pre‐column derivatisation with o‐phthalaldehyde (OPA) and N‐acetylcysteine (NAC), was compared with RPLC modes using trifluoroacetic acid or pentadecafluorooctanoic acid and evaporative light‐scattering detection, or sodium dodecyl sulphate micelles with pre‐ and post‐column derivatisation. The importance of column lifetime, risk of potential damages in the instrumentation, retention and resolution, was considered. Among the assayed approaches, the best is still aqueous‐organic RPLC with pre‐column derivatisation. It not only yields the most reliable results, but …