Synthesis, insecticidal activities and structure–activity relationship study of dual chiral sulfilimines

Abstract

To investigate the "methyl" impact on bioactivity of sulfiliminyl dicarboxamides, a total of 16 novel N-cyano and N-trifluoroacetyl sulfiliminyl dicarboxamides containing m-heptafluoroisopropylated aromatic amino moiety were studied. Two series of sulfiliminyl substituents were designed, synthesized and evaluated against oriental armyworm (Pseudaletia separata Walker) for their insecticidal activities. Their chemical structures were established by corresponding [Formula: see text] NMR, HRMS and optical polarimetry. Bioassay results revealed that some of the title compounds showed potent insecticidal activities against oriental armyworm. Notably, compounds IIa, IIIa, IVa exhibited 100% activity at [Formula: see text], in particular, IIa showed a comparable control efficacy to that of the commercial product flubendiamide. The SAR of these N-cyano sulfiliminyl isomers can be summarized as follows (Sc, Ss) [Formula: see text] (Sc, Rs), while the N-trifluoroacetyl sulfiliminyl isomers is (Sc, Rs) [Formula: see text] (Sc, Ss). Comparative molecular field analysis indicated that an electropositive substituent, [Formula: see text] group in the benzene ring was very important for the improvement in biological activity. These results could hold promise for novel chiral sulfiliminyl RyR regulators.