Bimetallic Cu/Pd-catalyzed three-component azide-alkyne cycloaddition/isocyanide insertion: synthesis of fully decorated tricyclic triazoles

Synthesis of 1,2,3-triazole-piperazin-benzo[b][1,4]thiazine 1,1-dioxides: antibacterial, hemolytic and in silico TLR4 protein inhibitory activities

In this study, we designed and synthesized a number of novel 1,2,3-triazole-piperazin-benzo[b][1,4]thiazine 1,1-dioxide derivatives and investigated their in vitro antibacterial and hemolytic activity. When compared to the lead chemical, dicloxacillin, the majority of the compounds demonstrated acceptable activity. Among them, the most promising compounds 6e, 6g, 6i, 8d, and 8e exhibited excellent antibacterial activity against the methicillin-susceptible S. aureus (MSSA), methicillin-resistant S. aureus (MRSA), and vancomycin-resistant S. aureus (VRSA) with MIC values of 1.56 ± 0.22 to 12.5 ± 1.75 μg mL-1, respectively, The percentage of hemolysis ranged from 21.3 μg mL-1 to 33.8 μg mL-1. Out of the six compounds (6i, 6e, 6f, 6g, 8e, 8d) tested compound 8e and 8d displayed minimal or negligible hemolytic activity across all the tested concentrations 29.6% and 30.2% recorded at 100 μg mL-1 concentration respectively. In silico docking studies were performed to evaluate the molecular interactions of 6e, 6f, 6g, 6i, 8d, and 8e compounds with Human, Mouse and Bovine TLR4 proteins (PDB: 3FXI, 3VQ1, 3RG1) and observed that three of the compounds (6i, 8d, and 8i) had appreciable binding energies ranging from -8.5 to -9.0 Kcal mol-1. Finally, the in silico pharmacokinetic profile was predicted for potent compounds 8d, 8e and 6i using SWISS/ADME, All compounds investigated in this study adhered to Lipinski's rule of five with slight deviation in molecular weight (8d and 8e).

Synthesis of fused bis-indazoles/indazoles via a one-pot sequential strategy

We report here an efficient synthesis of fused bis-indazoles/indazoles via a one-pot sequential strategy starting from o-azido aldehydes and amines. This novel method involves the sequential formation of 2H-indazole followed by a Pd-catalyzed intramolecular cross-dehydrogenative coupling reaction. Overall, this one-pot sequential reaction involved the formation of new five bonds, resulting in the formation of three heterocyclic rings.

A recent overview on the synthesis of 1,4,5-trisubstituted 1,2,3-triazoles

Diverse strategies for the efficient and attractive synthesis of a wide variety of relevant 1,4,5-trisubstituted 1,2,3-triazole molecules are reported. The synthesis of this category of diverse fully functionalized 1,2,3-triazoles has become a necessary and unique research subject in modern synthetic organic key transformations in academia, pharmacy, and industry. The current review aims to cover a wide literature survey of numerous synthetic strategies. Recent reports (2017–2021) in the field of 1,4,5-trisubstituted 1,2,3-triazoles are emphasized in this current review.

Fused benzo[1,3]thiazine-1,2,3-triazole hybrids: Microwave-assisted one-pot synthesis, in vitro antibacterial, antibiofilm, and in silico ADME studies

In this paper, we report an efficient one-pot three-component reaction sequences comprising Cu(I)-catalyzed 1,3-dipolar cycloaddition (CuAAC) followed by Cu-catalyzed arylation of resulting 1,2,3-triazole in the presence of ionic liquid [Emim]BF₄ under microwave conditions involving. The newly synthesized derivatives were screened for in vitro antibacterial inhibition potency against both gram +ve and gram -ve strains. Among the tested compounds, 4f exhibited significant inhibition activity with MIC value 3.12 µg/mL against B. subtilis and S. epidermidis which is two-fold higher than the standard ciprofloxacin (6.25 µg/mL) and also displayed equipotent activity to that of the positive control against S. aureus with MIC value 6.25 µg/mL. Conjugates of the series viz. 3f and 4b against S. aureus, and 4e against E. coli have also displayed promising results with MIC values 6.25 µg/mL which is comparable to the ciprofloxacin. Also we report the anti-biofilm profiles for the potent compounds and it was observed from the results that the active derivatives 4b and 4f were not only potent antibacterial agents but also efficient inhibitors of B. subtilis and S. aureus biofilm growth. Furthermore, in silico-ADME and pharmacokinetic profiles demonstrated the druggability of the hybrids.

Catalyst and solvent switched divergent C-H functionalization: oxidative annulation of N-aryl substituted quinazolin-4-amine with alkynes

The development of site-selective C-H functionalizations/annulations is one of the most challenging practices in synthetic organic chemistry particularly for substrates bearing several similarly reactive C-H bonds. Herein, we describe catalyst and solvent controlled ortho/peri site-selective oxidative annulation of C-H bonds of N-aryl substituted quinazolin-4-amines with internal alkynes. The ortho C-H selective annulation was observed using Pd-catalyst in DMF to give indole-quinazoline derivatives, while, Ru-catalyst in PEG-400 favoured the peri C-H bond annulation exclusively to furnish pyrido-quinazoline derivatives.