Design, Synthesis, and Insecticidal Activity of Mesoionic Pyrido[1,2- a ]pyrimidinone Containing Isoxazole/Isoxazoline Moiety as a Potential Insecticide.

Bean aphid ( Aphis craccivora ) resistance to commonly used insecticides has made controlling these pests increasingly difficult. In this study, we introduced isoxazole and isoxazoline, which possess insecticidal activity, into pyrido[1,2- a ]pyrimidinone through a scaffold hopping strategy. We designed and synthesized a series of novel mesoionic compounds that exhibited a range of insecticidal activities against A. craccivora . The LC 50 values of compounds E1 and E2 were 0.73 and 0.88 μg/mL, respectively, better than triflumezopyrim (LC 50 = 2.43 μg/mL). Proteomics and molecular docking analyses showed that E1 might influence the A. craccivora nervous system by interacting with neuronal nicotinic acetylcholine receptors (nAChRs). This research offers a new approach to the advancement of novel mesoionic insecticides.