Design,synthesis and insecticidal activities of novel anthranilic diamides containing polyfluoroalkyl pyrazole moiety

In order to discover new molecules with good insecticidal activities, a series of anthranilic diamides containing polyfluoroalkyl pyrazole were designed and synthesized, and their structures were characterized by ¹H NMR and HRMS. Bioassays demonstrated that some of the title compound exhibited excellent insecticidal activities. The larvicidal activities of compound 8a, 8c, 8g, 8k and 8l against Mythimna separata Walker were 100% at 0.8 mg/L. The insecticidal activities of compound 8a, 8c, 8e, 8g, 8k and 8l against Plutella xylostella Linnaeus were 100% at 0.4 mg/L. Surprisingly compounds 8a and 8c still showed 100% larvicidal activities against Plutella xylostella Linnaeus at 0.08 mg/L comparable to the commercialized Chlorantraniliprole. The LC₅₀ of compound 8a and 8c against M. separata is 0.048 and 0.043 mg/L respectively.     

A two-step approach to 2-polyfluoroalkyl quinolines from N-aryl polyfluoroalkyl imidoyl iodides

2-Polyfluoroalkyl quinoline derivatives were synthesized from the enaminones which were obtained from the reaction of N-aryl polyfluoroalkyl imidoyl iodides with methyl ketones.     

Stereoselective cycloaddition-lactonization reaction of 2-allyl-4-pentenoic acids with polyfluoroalkyl iodides. An efficient synthesis of polyfluoroalkyl-containing bicyclolactone derivatives

Polyfluoroalkyl-containing bicyclolactones were synthesized via the sodium dithionite-initiated cycloaddition-lactonization reaction of 2-allyl-4-pentenoic acids and polyfluoroalkyl iodides. The chemo- and stereo-selectivity of the cycloaddition-lactonization reaction strongly depended on the space hindrance of 2-substituent in 2-allyl-4-pentenoic acids. The reaction was believed to proceed through a tandem free radical addition-lactonization process.     

2-Polyfluoroalkyl thiopyrylium salts: synthesis and reactions with nucleophiles

2-Polyfluoroalkylthiopyrylium salts have been synthesized by oxidative aromatization of 2-polyfluoroalkyl-2H-thiopyrans with triphenylmethane tetrafluoroborate. Nucleophilic addition of methanol, sodium azide, or urea to 2-trifluoromethylthiopyrylium tetrafluoroborate in a basic medium proceeds at the α-position to give the corresponding 2-substituted 6-trifluoromethyl-2H-thiopyrans whereas imidazoles, fluorine-containing 1,2,3-triazole, potassium thiolacetate, and sodium nitromethane afford mixtures of 2H- and 4H-thiopyrans. cis-Dihydroxylation of 6-trifluoromethyl-2-methoxy-2H-thiopyran affords the fluorine-containing thiohexenopyranoside derivative 8.     

Improved selectivity for the analysis of maternal serum and cord serum for polyfluoroalkyl chemicals

Perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid, two of the most widely studied polyfluoroalkyl chemicals (PFCs), can cross the placenta. Therefore, data on the exposure to PFCs of the very young are needed to evaluate the potential health effects associated with such exposure. Human serum, especially serum collected from pregnant women and cord serum, may contain endogenous components that can interfere in the separation by high performance liquid chromatography (HPLC) of PFOS and another PFC of interest, perfluorohexane sulfonic acid (PFHxS), from other serum biomolecules. The presence of such interferences may prevent the adequate quantification of PFOS and PFHxS in cord serum or serum collected from pregnant women, and potentially hinder the assessment of gestational exposure to these important PFCs using biomonitoring. We have modified our on-line solid phase extraction-HPLC-isotope dilution-tandem mass spectrometry analytical method for measuring PFCs in serum and developed an approach that allows for the elimination of these potential interferences without compromising analytical sensitivity and throughput. The combination of acetonitrile as the HPLC mobile phase organic solvent and a Betasil C8 HPLC column provided the best separation of PFOS and PFHxS from interferent peaks. In addition to eliminating these interferences, the acetonitrile method has a shorter runtime and is more sensitive for most PFCs (limits of detection were 0.1 ng/mL except for PFOS (0.2 ng/mL)) than our previous method that used methanol for the HPLC separation. The present method should improve the precise and selective analysis of maternal and cord serum for PFCs.     

2,4-Bridged 1,5-bis(fluoroalkyl)-1,3,5-triketones: synthesis and properties

Symmetrical and unsymmetrical bis-fluoroacylcyclopentanones and cyclohexanones were synthesized. NMR data reveal that the keto-enol tautomeric equilibrium is changed markedly by the presence of a trimethylene bridge compared to an ethylene moiety. A considerable influence of the fluoroalkyl chain length was found for 2,6-(bisfluoroacyl)cyclohexanones.     

Analysis of 29 per- and polyfluorinated compounds in water,sediment, soil and sludge by liquid chromatography–tandem mass spectrometry

Several analytical methods were optimised for the analysis of 29 per- and polyfluoroalkyl substances (PFASs), including perfluorocarboxylic acids, perfluoroalkyl sulphonic acids and fluorotelomers (FTs), such as sulphonate, saturated carboxylic acid, unsaturated carboxylic acid, sulphonamide and sulphonamide betaine (FTAB), in environmental samples in order to assess pollution by PFASs around heavily contaminated sites. Non-filtered water samples were extracted, purified and pre-concentrated by a solid-phase extraction (SPE) procedure. Solid samples (sediments, soils and sludges) were extracted through solvent extraction under acidic conditions and thereafter purified and pre-concentrated using the same SPE procedure as for the water samples. An ultra-high performance liquid chromatography coupled to tandem mass spectrometry in negative electrospray ionisation mode was employed to separate and detect targeted compounds. Twelve labelled internal standards were used to provide an adequate correction compensating for matrix effects. The limits of quantification (LOQs) were between 4 and 10 ng/L in water depending on the analytes. For solid samples, the LOQs were 2 ng/g dry weight (dw) in sediments and soils, and 20 ng/g dw in sludges for all analytes. A surrogate parameter method based on the carboxylation of perfluoroalkyl acid precursors under basic pH conditions was furthermore implemented to estimate the occurrence of non-targeted PFAS compounds. In order to evaluate the reliability of these analytical methods, environmental samples collected around a training area in France, where aqueous fire-fighting foam is used, were analysed. Of all the compounds detected in these environmental samples, 6:2 FTAB was found in the highest concentrations.     

烯胺和含氟碘烷的单电子转移反应──α－氟烷基酮、醛的合成

由多氟烷基碘化物对烯胺的氟烷基化反应，合成了６种α－氟烷基酮和３种α－氟烷基醛并完成了它们的ＵＶ、ＩＲ、ＭＳ、１~ＨＮＭＲ和（１９）~ＦＮＭＲ结构鉴定及元素分析。通过活泼中间体的自旋截捕和抑制实验，揭示了本反应的单电子转移机理并发现ＳｍＩ_２的四氢呋喃溶液可催化本反应，使反应时间缩短、含氟酮产率提高。     

Reactions of ethyl triphenylphosphoranylideneacetate with fluorinated β-ketoaldehyde derivatives

The reactions of fluorinated β-ketoaldehyde derivatives: β-alkoxyvinyl polyfluoroalkyl ketones 1 and fluorinated β-ketoacetals 2 with ethyl triphenylphosphoranylideneacetate 3 are described. In the case of ketones 1 the result of the reaction is a mixture of products: fluorinated alkoxydienes 5 (Wittig reaction product) and polyfluoroacyl vinyl ylides 7 (Michael addition product). The reaction with fluorinated β-ketoacetals 2 leads to a mixture of E- and Z-isomers of polyfluoroalkyl acrylates 8 and 9, respectively. The influence of the nature of fluorinated substituent and solvent or other factors on the outcome of the reactions are discussed.     

Synthesis and some chemical properties of the 6-arylsulfonyl-6-polyfluoroalkanoyl-5,6-dihydro-2H-thiins—new fluorine-containing ketones

1,1-Dihydro-1-tolylsulfonyl polyfluoroalkan-2-ones react with phthalimidosulfenyl chloride to form sulfenylated products on the active methylene group, 1-phthalimidothio-1-tolylsulfonyl polyfluoroalkan-2-ones. Decomposition of the latter leads to formation of 1-thioxo-1-tolylsulfonyl polyfluoroalkan-2-ones. These compounds undergo easily the hetero Diels-Alder reaction with electron-rich 1,3-dienes as dienophiles to give polyfluoroalkanoyl substituted derivatives of 5,6-dihydro-2H-thiins. 6-Arylsulfonyl-6-polyfluoroalkanoyl-5,6-dihydro-2H-thiins obtained react with alkali to give 5,6-dihydro-6-p-tolylsulfonyl-2H-thiins and with methanol to give 2-polyfluoroalkanoyl-6H-thiins.