PCy3-assisted Ag(I)-catalyzed click reaction for regioselective synthesis of 1,4-disubstituted 1,2,3-triazoles at room temperature.

An approach towards Cu-free click chemistry has been developed in this work. Silver-catalyzed PCy3-ligand-assisted synthesis of 1,4-disubstituted 1,2,3-triazoles at room temperature has been developed. Regioselectivity of the reaction was confirmed from the results of single-crystal X-ray diffraction (SC-XRD) of one of the products. SC-XRD of ex situ-generated Ag-PCy3 complex helped us propose a plausible mechanism for the reaction. This reaction was indicated to exhibit a catalytic activity level similar to that for the in situ-generated complex. The methodology was found to work well with benzyl azides, phenyl azides, terminal alkynes and internal alkynes in aqueous medium. The one-pot three-component reaction leading to 1,2,3-triazole synthesis also proceeded well.

Recent Advances in Metal Free Synthesis of N-unsubstituted 1,2,3-Triazoles.

1, 2, 3-triazoles display enormous applications in the extensive fields of chemistry such as pharmaceuticals, ligands, conjectures, etc. Among these classes of compounds, the N-unsubstituted triazole emerges as a potent applicant for various fields of chemistry and therefore synthetic procedures for this molecular scaffold possess certain importance. Moreover, from an environmental perspective, metal-free organic synthesis gains tremendous attention as most of the metals are persistent in nature. In this review, we are going to discuss only the metal-free synthetic routes for the construction of N-unsubstituted 1,2,3-triazoles reported during the last decade.

Removal of As(III)/As(V) from aqueous solution using newly developed thiosalicylic acid coated magnetite [TSA@Fe3O4] nanoparticles.

The aim of this study was to develop an affordable adsorption methodology for removal of As(III)/As(V) from contaminated water. Herein, novel adsorbent TSA@Fe3O4 nanoparticles (NPs) were synthesized by decorating thiosalicylic acid (TSA) on magnetite nanoparticles (Fe3O4 NPs) and employed for removal of As(III)/As(V) species from artificially contaminated natural water systems. TSA@Fe3O4 NPs demonstrated excellent adsorption efficiency (AE) and 98% of As(V) and 93% of As(III) was removed at optimized experimental conditions. The adsorption kinetic and equilibrium isotherm studies were conducted preferentially for As(III) adsorption. Adsorption followed the pseudo-second-order kinetic (R2 = 99%) and adsorption data fitted well in Langmuir isotherm model (R2 = 99%) and maximum adsorption capacity (Qmax = 34.1 mg/g) was calculated for 5 mg/L of As(III) by using 10 mg of TSA@Fe3O4 NPs. The effect of pH, contact time, adsorption dosages, and competitive anions was also examined to identify optimum experimental conditions. The adsorbent was characterized by advanced instrumental techniques to investigate the physicochemical properties and stability of NPs. To comprehend the interactions of As(III) species with adsorbent NPs, NPs were analyzed using XPS and Raman spectroscopy techniques. Both the techniques confirmed that As(III) and As(V) species present simultaneously on adsorbent surface. The TSA@Fe3O4 was regenerated using 0.1 M NaOH. The findings of this study suggested that TSA@Fe3O4 NPs could be considered a potential adsorbent for effective remediation of As(III) and As(V) from contaminated natural water systems.

Design and Synthesis of Quinazolinone-Triazole Hybrids as Potent Anti-Tubercular Agents.

A straightforward and convenient methodology has been developed for the reaction of 2-aminobenzamide and carbonyls affording 2,3-dihydroquinazolin-4(1H)-ones using aqueous solution of [C12Py][FeCl3Br]. The developed methodology was applied for the synthesis of 25 quinazolinone-triazole hybrids followed by evaluation of their in vitro anti-tubercular (TB) activity. The results revealed that 8 quinazolinone-triazole hybrids displayed promising activity having MIC values of 0.78-12.5 µg/mL. The compound 3if with MIC 0.78 µg/mL was found to be the lead nominee among the series, better than Ethambutol, a first line anti-TB drug and comparable with Rifampicin. The active compounds with MIC values ≤ 6.25 µg/mL were subjected to in vitro cytotoxicity and found nontoxic. In drug-drug interaction, compounds 3ia and 3ii interacted synergistically with all the three anti-TB drugs, INH, RFM, and EMB. Other 3 compounds interacted either in synergistic or additive manners. Important information on the binding interaction of the target compounds with the active sites of 1DQY Antigen 85C from Mycobacterium tuberculosis and Enoyl acyl carrier protein reductase (InhA) enzymes was obtained from molecular docking studies. Screening of the drug-likeness properties and bioactivity score indicates that synthesized molecules could be projected as potential drug candidates. Based on the current study, quinazolinone-triazole hybrids framework can be useful in drug development for TB.