Design, Synthesis and Bioactivities of Novel Dichloro-Allyloxy-Phenol-Containing Pyrazole Oxime Derivatives
In this study, in order to find novel biologically active pyrazole oxime compounds, a number of dichloro-allyloxy-phenol-containing pyrazole oximes were designed and synthesized according to the method of active group combination. All of the target compounds were confirmed by 1H-NMR, 13C-NMR and elemental analysis. In addition, bioassays showed that all of the newly synthesized compounds had no acaricidal activity against Tetranychus cinnabarinus and low insecticidal activity against Aphis craccivora at tested concentrations. However, most of them displayed excellent insecticidal activity against Oriental armyworm at a concentration of 500 μg/mL, and some designed compounds still exhibited potent insecticidal activity against Oriental armyworm even at the dose of 20 μg/mL, especially compounds 7f, 7n and 7p had 100%, 90% and 90% inhibition rates, respectively, which were comparable to that of the control pyridalyl.
Discovery of nitropyridyl-based dichloropropene ethers as insecticides.
A series of nitropyridyl-based dichloropropene ethers were prepared and evaluated for their insecticidal activities against main lepidopteran pests such as M. separate, P. xylostella and P. litura. The compounds showed a broad-spectrum of remarkable insecticidal activities. Especially 4a (2,6-dichloro-4-(3,3-dichloroallyloxy)phenyl 3-[5-nitro-2-pyridyloxy]propyl ether) and 11a (2-(4-(3-(2,6-dichloro-4-((3,3-dichloroallyl)oxy)phenoxy)propoxy)phenoxy)-5-nitropyridine) displayed potent activities comparable to that of Pyridalyl, the only commercialized dichloropropene ether insecticide thus far. The structure-activity relationship was also discussed.
Highly enantio- and diastereoselective synthesis of β-methyl-γ-monofluoromethyl-substituted alcohols.
Enanatiopure β-methyl-γ-monofluoromethyl alcohols were prepared from the allylic alkylation between fluorobis(phenylsulfonyl)methane with Morita-Baylis-Hillman carbonates. The reaction was catalyzed by using the Cinchona alkaloid derivative, (DHQD)(2)AQN. The origin of the stereoselectivity was verified by DFT methods. Calculated geometries and relative energies of various transition states strongly support the observed stereoselectivity.