Herein, we describe novel pentafluorosulfanyl (SF₅) group-containing meta-diamide insecticides. For the facile preparation of the SF₅-based compounds 4a–d, practical synthetic methods were applied. Among newly synthesized compounds, 3-benzamido-N-(2,6-dimethyl-4-(pentafluoro-λ⁶-sulfanyl)phenyl)-2-fluorobenzamide 4d showed (i) a high insecticidal activity, (ii) an excellent selectivity to insects, and (iii) good levels of water solubility and log P values. In this study, we demonstrated that the pentafluorosulfanyl moiety could serve as an attractive functionality for the discovery of a new scope of crop-protecting agents.

The one-pot preparation of 2,3-disubstituted 4-quinolones and the structural assignment of their tautomers are described. The mono-selective Michael addition of anilines to α,α-dioxoketene dithioacetals followed by thermal cyclization of the crude N,S-acetals gave the desired 4-hydroxyquinolines in good to excellent yields. The tautomeric structures of the obtained products were confirmed by X-ray crystallography, IR, and NMR experiments. Spectroscopic data revealed that the equilibrium between the enol and keto forms of the bicyclic system was determined by the strength of the internal H-bonds. A H-bond acceptor at the 3-position favored the enol form via 6-membered intramolecular H-bonding. A H-bond acceptor at the 2- or 8-position completely switched the equilibrium to favor the keto form possibly due to extended conjugation and H-bonding. The experimental assignments were perfectly matched with the results of DFT calculation.