Chiral 1,5-disubstituted 1,3,5-hexahydrotriazine-2-N-nitroimine analogues as novel potent neonicotinoids: Synthesis, insecticidal evaluation and molecular docking studies.

A new series of 1,5-disubstituted 1,3,5-hexahydrotriazine-2-N-nitroimines (4a-4x) were designed and synthesized as novel chiral neonicotinoid analogues. The single-crystal structure of 4n was further determined by X-ray diffraction, and its S configuration was confirmed. Preliminary bioassay showed that compound 4e, 4k, 4u, 4v exhibited excellent insecticidal activities at 100 mg/L, while 4k had >90% mortality at 10 mg/L, which suggested it could be used as a lead for future development. Modeling the inhibitor-nAChR complexes by molecular docking studies explained the structure-activity relationships observed in vitro, and revealed an intriguing molecular binding mode at the active site of nAChR, which raised the possibility that these analogues may arbitrate their insecticidal activity through a mechanism other than imidacloprid.