The first 1,3-dipolar cycloaddition of 2-azirines with nitrones, a straightforward approach toward the regioselective synthesis of 1,2,4,5-tetrasubstituted imidazoles, is reported. This trifluoroacetic acid-catalyzed protocol tolerates a broad range of aliphatic and aromatic substrates, offering an efficient access to highly diverse, multisubstituted imidazoles in isolated yields up to 83% under mild conditions.
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http://dx.doi.org/10.1021/acs.joc.9b03288 | DOI Listing |
J Colloid Interface Sci
December 2024
Laboratory of Alternative Energy Conversion Systems, Department of Mechanical Engineering, School of Engineering, University of Thessaly, Pedion Areos 38834, Greece. Electronic address:
The coupling of carbon dioxide (CO) with epoxides to produce cyclic carbonates is a desirable decarbonization approach, but its commercial applicability is still restricted by the costly catalysts required, as well as the need for high temperature and high pressure. Herein, oxygen vacancy-rich defective tungsten oxide (WO) rich in Lewis acid sites was modified by Prussian blue (PB), and the obtained composite reaches up to 94 % styrene carbonate yield (171 mmol gh) at ambient temperature and pressure, exhibiting outstanding advantages in the photocatalytic CO cycloaddition reaction compared with currently reported photocatalysts. It is found that the introduction of PB with photothermal properties significantly enhances the capability of WO to absorb and activate CO and epoxide, along with its light utilization ability.
View Article and Find Full Text PDFEur J Med Chem
December 2024
Department of Natural Products and Medicinal Chemistry, CSIR-IICT Hyderabad, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India. Electronic address:
Investigations into fruit and vegetable processing residues (FVPRs) offer huge opportunities to discover novel therapeutics against many diseases. In this study, detailed investigation of Garcinia mangostana fruit peel extract led to the isolation and identification of ten known compounds (1-10). Further, a new series of α-mangostin derived sulphonyl piperzines, aryl alkynes and 1,2,3-triazole derivatives were synthesized using Huisgen 1,3-dipolar cyclo-addition reaction ("click" chemistry).
View Article and Find Full Text PDFJ Mol Model
January 2025
Department of Theoretical Chemistry, Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387, Krakow, Poland.
Context: The analysis of the changes in the electronic structure along intrinsic reaction coordinate (IRC) paths for model reactions: (i) ethylene + butadiene cycloaddition, (ii) prototype SN2 reaction Cl + CH3Cl, (iii) HCN/CNH isomerization assisted by water, (iv) CO + HF → C(O)HF was performed, in terms of changes in the deformation density (Δr) and the deformation of MEP (ΔMEP). The main goal was to further examine the utility of the ΔMEP as a descriptor of chemical bonding, and to compare the pictures resulting from Δr and ΔMEP. Both approaches clearly show that the main changes in the electronic structure occur in the TS region.
View Article and Find Full Text PDFChem Commun (Camb)
January 2025
Institute of Organic Chemistry, Polish Academy of Sciences, 01-224 Warsaw, Kasprzaka 44/52, Poland.
We report the synthesis, isolation, and comprehensive characterization of N-heterocyclic carbene gold xanthate (NHC-Au-X, X - xanthate) complexes. These easily accessible complexes demonstrate significant versatility as photocatalysts, facilitating [2+2]-cycloadditions, and as π-catalysts in the intramolecular hydroxylation of allenes and hydrohydrazination of alkynes.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen 518132, China.
Small-molecule fluorophores are invaluable tools for fluorescence imaging. However, means for their covalent conjugation to the target proteins limit applications in multicolor imaging. Here, we identify 2-[(alkylhio)(ryl)ethylene]alononitrile (TAMM) molecules reacting with 1,2-aminothiol at a labeling rate over 10 M s through detailed mechanistic investigation.
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