New Carboxytriazolyl Amphiphilic Derivatives of Calix[4]arenes: Aggregation and Use in CuAAC Catalysis

This work focuses on the synthesis of a new series of amphiphilic derivatives of calix[4]arenes for the copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) reaction. The aggregation properties of synthesized calix[4]arenes were studied using various techniques (fluorescence spectroscopy, nanoparticle tracking analysis, and dynamic light scattering). Increasing the length of the alkyl substituent led to stronger hydrophobic interactions, which increased polydispersity in solution. The zwitterionic nature of the synthesized calix[4]arenes was established using different types of dyes (Eosin Y for anionic structures and Rhodamine 6G for cationic structures). The synthesized calix[4]arenes were used as organic stabilizers for CuI. The catalytic efficiency of CuI-calix[4]arene was compared with that of the phase transfer catalyst tetrabutylammonium bromide (TBAB) and the surfactant sodium dodecyl sulfate (SDS). For all calixarenes, the selectivity in the CuAAC reaction was higher than that observed when TBAB and SDS were estimated.

Gold(i)-silver(i)-calix[8]arene complexes, precursors of bimetallic alloyed Au-Ag nanoparticles

In this paper, we report the first synthesis and characterisations of bimetallic gold(i)-silver(i) calix[8]arene complexes. We show that the radiolytic reduction of these complexes leads to the formation of small bimetallic nanoparticles with an alloyed structure, as evidenced by XPS, HR-TEM and STEM/HAADF-EDX measurements.

Bioactive-guided structural optimization of 1,2,3-triazole phenylhydrazones as potential fungicides against Fusarium graminearum

The phytopathogenic fungus Fusarium graminearum is the major causal agent of fusarium head blight (FHB), which is one of the most serious diseases in wheat. Based on our previous work, the 1,2,3-triazole phenylhydrazone scaffold was further optimized at three modification sites to improve its antifungal activity against F. graminearum. The optimization yielded compound 8d was discovered to be a potent fungicidal agent with an EC₅₀ value of 0.28 μg/mL against F. graminearum, which is 3.6 times lower than previously reported. In addition, 8d also exhibited good inhibitory activities against Rhizoctonia solani and Sclerotinia sclerotiorum with EC₅₀ values of 0.86 and 1.66 μg/mL, respectively. In vivo testing demonstrated that 8d could effectively suppress the disease development of FHB at 200 μg/mL with a protection efficacy of 80.6%. Scanning electron micrographs and transmission electron micrographs showed that the external morphology and internal contents of F. graminearum hyphae were abnormal after 24 h of 8d treatment. Therefore, compound 8d was a promising fungicide candidate for further development.

Copper ferrite nanoparticle modified starch as a highly recoverable catalyst for room temperature click chemistry: multicomponent synthesis of 1,2,3-triazoles in water

Highly water dispersible CuFe₂O₄@Starch catalyzed click reaction.

Green click synthesis of β-hydroxy-1,2,3-triazoles in water in the presence of a Cu(ii)–azide catalyst: a new function for Cu(ii)–azide complexes

A new method for preparing 1,2,3-triazols via a [3+2]-cycloaddition reaction is introduced. The effect of reaction temperature on the epoxide ring opening reactions is also investigated.