Synthesis of novel 1,2,3-triazole-containing pyridine–pyrazole amide derivatives based on one-pot click reaction and their evaluation for potent nematicidal activity against Meloidogyne incognita

Synthesis, biological activity and toxicity to zebrafish of benzamides substituted with pyrazole-linked 1,2,4-oxadiazole

To find pesticidal lead compounds with high activity, a series of novel benzamides substituted with pyrazole-linked 1,2,4-oxadiazole was designed and synthesized by using the splicing principle of active substructures. The chemical structures of the target compounds were confirmed by 1H NMR, 13C NMR and HRMS. The preliminary bioassay showed that most compounds displayed good larvicidal activities against mosquito larvae at 10 mg L-1. In particular, compound 12g exhibited obvious activity; its lethal rate reached up to 100% (at 5 mg L-1) and 55% (at only 2 mg L-1). Furthermore, compound 12f (70.6%) and 12h (100%) showed good fungicidal activities against Pyricularia oryzae, with EC50 values of 8.28 and 5.49 μg mL-1, respectively, which were superior to that of the control drug bixafen (9.15 μg mL-1). Finally, the LC50 of compound 12h to zebrafish embryo was 0.39 mg L-1, so it was classified as a high-toxic compound. Thus, this compound may be used as a potential lead compound for further structural optimisation to develop new compounds with high activity and low toxicity.

Chemical Nematicides: Recent Research Progress and Outlook

Plant-parasitic nematodes have caused huge economic losses to agriculture worldwide and seriously threaten the sustainable development of modern agriculture. Chemical nematicides are still the most effective means to manage nematodes. However, the long-term use of organophosphorus and carbamate nematicides has led to a lack of field control efficacy and increased nematode resistance. To meet the huge market demand and slow the growth of resistance, new nematicides are needed to enter the market. The rational design and synthesis of new chemical scaffolds to screen for new nematicides is still a difficult task. We reviewed the latest research progress of nematicidal compounds in the past decade, discussed the structure-activity relationship and mechanism of action, and recommended some nematicidal active fragments. It is hoped that this review can update the recent progress on nematicide discoveries and provide new ideas for the design and mechanism of action studies of nematicides.

Sequential one-pot three-step synthesis of polysubstituted 4-(5-(trifluoromethyl)-1H-pyrazol-4-yl)-1H-1,2,3-triazole systems

Sequential one-pot, three-step synthesis of polysubstituted 4-(5-(trifluoromethyl)-1H-pyrazol-4-yl)-1H-1,2,3-triazoles.