جستجوی مقالات مرتبط با کلیدواژه « click reaction » در نشریات گروه « شیمی »

Efficient functionalization of Fumed silica by sulfonamides via copper-catalyzed Huisgen 1,3-dipolar cycloaddition (Click) reaction has been reported. Functionalization of Fumed silica by 3-azidopropyl groups leads to the formation of azide moiety as building blocks for Click reaction. Propargylation of three commercial sulfonamides (sulfadiazine, sulfadimidine, and sulfaquinoxaline), with propargyl bromide, leads to the formation of another building block for Click reaction. The Click reaction was catalyzed by freshly prepared Copper(I) iodide in DMF at room temperature after 72 hours. Antimicrobial activities of sulfonamides functionalized Fumed silica were measured against Staphylococcus aureus as gram-positive bacteria and Escherichia coli as gram-negative bacteria and checked by their Zeta potentials.

In this research work novel PVC-supported triazole-copper(I) iodide catalyst (PVC–Triazole–CuI) was prepared and used the for synthesis of 1,2,3-triazoles. The catalyst was prepared in two steps; First PVC-N3 obtained from the reaction of NaN3 with PVC in water, then reaction of this compound with propargyl alcohol and copper(I)iodide in ethanol led to PVC-Triazole-CuI as the catalyst. The structure of the catalyst was characterized via different analytical tools, such as FT-IR, elemental analysis, ICP and SEM. This catalytic system was successfully applied for the three-component synthesis of 1,4-disubstituted 1,2,3-triazoles by the click reaction of terminal alkynes, sodium azide and organic halides. The advantages of this method are high reaction yield, short reaction time, and capability of recovering and reusing the catalyst. In addition, water, as a green medium, is used in the synthesis of 1,2,3-triazoles.

Synthesis of 1,4-disubstituted 1,2,3- triazoles in the presence of SMI-CuI catalyst has been modeled by means of density functional theory in terms of structural and thermochemical aspects in the gas phase and also in the presence of three different solvents; ethanol, acetonitrile and water via polarized continuum model. Based on the calculated thermodynamical properties of the reaction, we have shown that the production of 1,4 disubstituded 1,2,3-triazole is more favourable thermodynamically. Moreover, from thermodynamic point of view, we have determined acetonitrile as more appropriate solvent.
In the next step, the structural and energetic properties of the corresponded transition states to 1,4 and 1,5 disubstituted 1,2,3-triazole products, considering SMI-CuI catalyst effect, were assessed to interpret the origins of regioselectivity. Additionally, we have analyzed the regioselective behavior of the synthesis electronically, based on the quantum theory of atoms in molecules calculations.

The triazole core is an important part of the therapeutically drugs such as antimicrobial, analgesic and anti-inflammatory agents. Therefore, a facile synthesis of a series of 1,2,3-triazoles has been introduced by the sequential azidation of alcohols or epoxides and then Cu (I)-catalyzed azide-alkyne cycloaddition (CuAAC) in water. The biological profiles of some of these five-membered heterocyclic scaffolds toward anti-bacterial activities were evaluated using Kirby-Bauer Disc Diffusion method. The biological obtained results were very interesting and revealed that most of the examined molecules are potent antibacterial agents when compared with standard drugs.