91-15-6Relevant articles and documents
Polyfunctionalized Cage Compounds by Pericyclic Domino Processes of 4,5-Dicyanopyridazine with Dienes: Applications and Limits
Giomi, Donatella,Nesi, Rodolfo,Turchi, Stefania,Mura, Elena
, p. 360 - 364 (2000)
The title compound 1 was found to behave as an attractive masked bis-diene to give 4-oxatricyclo-[4.3.1.03,7]dec-8-ene, 5-aza- and 5-silatricyclo[5.3.1.03,8]undec-9-ene, tricyclo[3.2.1.02,7]oct-3-ene, and tricyclo[5.3.1.03,8]undec-9-ene derivatives through purely pericyclic, three-step homodomino processes with diverse bis-dienophiles; whereas the reaction with myrcene (21) was characterized by a complete sitoselectivity affording compound 25, treatment of 1 with (R)-(-)-β-citronellene (26a) gave a 3:1 mixture of the homochiral diastereomers 30a and 31a. Some limits of this methodology, mainly arising from competitive side reactions upon the key cyclohexa-1,3-diene intermediates, are emphasized. The structures of the new compounds were established on the basis of spectral data.
Switchable activity of a Ru catalyst bearing an annulated mesoionic carbene ligand for oxidation of primary amines
Bera, Jitendra K.,Din Reshi, Noor U,Pal, Nilay Kumar,Pal, Saikat,Pal, Sourav,Yadav, Suman
, (2022/01/31)
The catalytic activity of a Ru complex 1, bearing a fused π-conjugated imidazo[1,2–a][1,8]naphthyridine-based mesoionic carbene (MIC) ligand, is examined for the oxidation of primary amines. Complex 1 affords nitrile or imine depending on the nature of th
Chemical Modifications Induced by Phthalic Anhydride, a Respiratory Sensitizer, in Reconstructed Human Epidermis: A Combined HRMAS NMR and LC-MS/MS Proteomic Approach
Khong, Minh-Thuong,Berl, Valérie,Kuhn, Lauriane,Hammann, Philippe,Lepoittevin, Jean-Pierre
, p. 2087 - 2099 (2021/08/30)
Chemical skin and respiratory allergies are becoming a major health problem. To date our knowledge on the process of protein haptenation is still limited and mainly derived from studies performed in solution using model nucleophiles. In order to better understand chemical interactions between chemical allergens and the skin, we have investigated the reactivity of phthalic anhydride 1 (PA), a chemical respiratory sensitizer, toward reconstructed human epidermis (RHE). This study was performed using a new approach combining HRMAS NMR to investigate the in situ chemical reactivity and LC-MS/MS to identify modified epidermal proteins. In RHE, the reaction of PA appeared to be quite fast and the major product formed was phthalic acid. Two amide type adducts on lysine residues were observed and after 8h of incubation, we also observed the formation of an imide type cyclized adducts with lysine. In parallel, RHE samples topically exposed to phthalic anhydride (13C)-1 were analyzed using the shotgun proteomics method. Thus, 948 different proteins were extracted and identified, 135 of which being modified by PA, i.e., 14.2% of the extracted proteome. A total of 211 amino acids were modified by PA and validated by fragmentation spectra. We thus identified 154 modified lysines, 22 modified histidines, 30 modified tyrosines, and 5 modified arginines. The rate of modified residues, as a proportion of the total number of modifiable nucleophilic residues in RHE, was rather low (1%). At the protein level, modified proteins were mainly type I and type II keratins and other proteins which are abundant in the epidermis such as protein S100A, Caspase 14, annexin A2, serpin B3, fatty-acid binding protein 5, histone H2, H3, H4, etc. However, the most modified protein, mainly on histidine residues, was filaggrin, a protein that is of low abundance (0.0266 mol %) and rich in histidine.
A Versatile VMPO Catalyst Prepared In Situ for Oxidative Ammonolysis of Isomeric Picolines and Xylenes
Dutta, P.,Pathak, D. D.,Senapati, Rabinarayan
, p. 292 - 298 (2020/04/17)
Abstract: The V2O5–MoO3–P2O5 (VMPO) catalyst has been prepared in situ by thermal decomposition of vanado-molybdophosphoric acid (PMoV) on TiO2 support at 475°C. The TiO2 supported VMPO catalysts are characterized by FT–IR, XRD, BET surface area, NH3–TPD, and H2–TPR. Morphology of the catalyst has been studied by TEM. The accumulated data indicate decomposition of PMoV and presence of phosphate and pyrophosphate phases of molybdenum and vanadium after calcination. TPD and TPR studies exhibit the moderate acidity and presence of V4+ in the material, respectively. The VMPO catalyst has been used for ammoxidation of six different compounds including three isomeric picolines and three isomeric xylenes to the corresponding nitriles with the yield of 90–96%.