Nitromethylene Neonicotinoids Analogues with Tetrahydropyrimidine Fixed cis-Configuration: Synthesis, Insecticidal Activities, and Molecular Docking Studies

Two series of new nitromethylene neonicotinoid analogues (2a-2h and 3a-3h) were designed and prepared, with the cis-configuration confirmed by X-ray diffraction. Preliminary bioassays showed that most analogues exhibited excellent insecticidal activities at 500 mg/L, and analogues with optical activity (2c-2g) were highly potent at 100 mg/L, while compound 2d had >90% mortality at 20 mg/L, which suggested that it could be used as a lead for future insecticides development. Modeling the ligand-receptor complexes by molecular docking study explained the structure-activity relationships observed in vitro and revealed an intriguing molecular binding mode at the active site of the nAChR model, thereby possibly providing some useful information for future receptor structure-based designs of novel insecticidal compounds.