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

To investigate the "methyl" impact on bioactivity of sulfiliminyl dicarboxamides, a total of 16 novel N-cyano and N-trifluoroacetyl sulfiliminyl dicarboxamides containingm-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 H-1 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 1mg L-1, 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) = (Sc, Rs), while the Ntrifluoroacetyl sulfiliminyl isomers is (Sc, Rs) = (Sc, Ss). Comparative molecular field analysis indicated that an electropositive substituent, CH3 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.