Design, Synthesis and Fungicidal Activities of Novel 1,2,3-Triazole Functionalized Strobilurins

A series of new strobilurin derivatives bearing different 1,2,3-triazole side chains were designed and synthesized. The target compounds were characterized by HRMS, H-1 NMR, C-13 NMR spectra. Among them, the structure of compound 5q was confirmed by X-ray single crystal diffraction. All of the target compounds were evaluated in vitro for their fungicidal activity against Gibberella zeae, Phytophythora capsici, Alternaria alternate, Botrytis cinerea and Sclerotonia sclerotiorum at a concentration of 25 mg/L. The bio-assay results exhibited that some of them showed moderate to good fungicidal activity against Phytophythora capsici and Alternaria alternate. The inhibition rates of compound 5f and 5g were up to 73.6% against Phytophythora capsic, which were significantly higher than 42.5% for Difenoconazole. Preliminary structure-activity relationships (SAR) were also discussed.