ZrCl₄-Catalyzed C-O Bond to C-N Bond Formation: Synthesis of 1,2,3-Triazoles and Their Biological Evaluation

<div><p></p><p>A simple and efficient protocol was developed for the synthesis of aryl azides directly from aryl carbinols using ZrCl₄ as a Lewis acid catalyst. The azides were converted to novel triazoles under click reaction conditions, which were evaluated for their antimicrobial activity against various strains.</p> </div

Total syntheses of surinone B, alatanones A–B, and trineurone A

<p>The total syntheses of four polyketides, surinone B (<b>1</b>), alatanones A–B (<b>2</b>–<b>3</b>), and trineurone A (<b>4</b>) were accomplished through an efficient and unified strategy via one-pot C-acylation reaction coupling 1,3-cyclohexadiones with EDC-activated acids under mild conditions. Alatanone A (<b>2</b>) was found to be a potent anti-microbial agent against Gram-positive and Gram-negative bacteria with MIC 31.25 μg/ml while alatanone B (<b>3</b>) was found to be a potent anti-fungal agent against <i>Cladosporium cladosporioides</i> with MIC 62.5 μg/ml compared to cycloheximide MIC 125 μg/ml. Our methodology allows performing kilogram scale of these scarce polyketides for the development of new antimicrobials.</p

Magnetically Recyclable Nano-Fe₂O₃-Catalyzed Chemoselective Synthesis and Antioxidant Activity of Diethyl (3-((5-Aryl-1<i>H</i>-1,2,4-triazol-3-yl)thio)propyl)phosphonates

<div><p></p><p>An efficient, green, and chemoselective S-alkylation of 5-aryl-1<i>H</i>-1,2,4-triazole-3-thiones with diethyl (3-bromopropyl)phosphonate in water, catalyzed by nano-Fe₂O₃ under ligand- and base-free conditions, is reported. Clean reaction, less expensive catalyst, excellent yields, and easy workup are the advantages of the present method. The catalyst can be easily collected by a magnet and recycled without significant loss in catalytic activity. The newly synthesized compounds were screened for their antioxidant property by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging assay. The majority of the compounds exhibited good antioxidant activity.</p> </div