Discovery of Trifluorobutene Amide Derivatives as Potential Nematicides: Design, Synthesis, Nematicidal Activity Evaluation, SAR, and Mode of Action Study.

Plant-parasitic nematodes are one of the major threats to crop protection. However, only limited nematicides are currently available and are confronted with a growing resistance problem, which necessitates the development of novel nematicides. In this study, a series of trifluorobutene amide derivatives was synthesized through the strategy of amide bond reversal, and their nematicidal activity against was evaluated. The bioassay showed that compounds , , and and some analogues thereof exhibited good nematicidal activity. Among them, the derivatives of compound containing a benzene ring [ (R = 2-CH) and (R = 2-Cl)] exhibited excellent bioactivity against in vitro. The LC values reached 14.13 and 14.71 mg·L, respectively. Moreover, analogues of compounds and containing a thiophene ring [ (R = 5-CH), (R = 4-CH), and (R = 5-Cl)] exhibited significant bioactivity against in vivo with inhibition rates of 68.8, 65.5, and 69.8% at 2.5 mg·L in a matrix, respectively. Meanwhile, and also showed excellent control effects against in both cups and microplots. The structure-activity relationship (SAR) of synthesized compounds was discussed in detail. Comparative molecular field analysis (CoMFA) was also conducted to develop the SAR profile. The preliminary mode of action investigation showed that compound exhibited strong inhibition on egg hatching, motility, feeding behavior, and growth of . At the same time, the impact of active compounds on biochemical indicators related to oxidative stress showed that compound influenced the production of ROS (reactive oxygen species), and the accumulation of lipofuscin and lipids on .