Design, Synthesis, and Insecticidal Activities of Novel Analogues of Neonicotinoids: Replacement of Nitromethylene with Nitroconjugated System

To replace nitromethylene pharmacophore with a nitroconjugated system, a series of novel neonicotinoid analogues bearing five-membered aromatic heterocycles were designed and synthesized. Bioassays indicated that some of the synthesized compounds exhibited higher insecticidal activities than imidacloprid against cowpea aphids ( Aphis craccivora ), armyworm ( Pseudaletia separate Walker), Nephotettix bipunctatus (Fabricius), and small brown rice planthopper ( Laodelphasx striatellus ). Exhilaratingly, the activity levels of derivatives 13a and 13j rivaled that of imidacloprid.