Recent Advances in the Pesticide Activities of 2-Cyanoacrylate Derivatives

Catalyst-Free Selective Synthesis of E-Tetrasubstituted Olefins via Tandem Reaction of 3-Acetyl-4-phenyl-1-oxaspiro[4.5]deca-3,6,9-triene-2,8-dione with Amine, C-C Bond Breakage, and Proton Transfer

The Z- or E-selective syntheses of tetrasubstituted olefins present big challenges. Tremendous efforts are ongoing to overcome this issue, especially for acyclic structures. In this work, an E-stereoselective synthetic method of tetrasubstituted olefins through tandem reaction of 1,4-Michael addition of 3-acetyl-4-phenyl-1-oxaspiro[4.5]deca-3,6,9-triene-2,8-dione with amine, C-C bond breakage, and proton transfer by intermolecular hydrogen bonds was revealed with excellent atom economy and without catalysts and additives. A diverse set of E-tetrasubstituted olefins were obtained in 43% to 93% yields with excellent functional group tolerance for late-stage modifications of complex drug molecules. The reaction mechanism was proposed based on the deuterium-labeling experiment and density functional theory (DFT) calculation.

Benzimidazole-acrylonitrile hybrid derivatives act as potent urease inhibitors with possible fungicidal activity

Aim: A series of benzimidazole-acrylonitrile derivatives TM1-TM53 were designed with urease inhibition approach.Materials & methods: TM1-TM53 were synthesized and characterized (1H Nuclear Magnetic Resonance (NMR), 13C NMR, Mass Spectroscopy (MS) and IR) and subjected to urease inhibition assay using commercial assay kit. A molecular docking study was also performed using Autodock tool software.Results: Except six compounds, target molecules exhibited a higher urease inhibition effect (IC50: 1.22-28.45 μM) than hydroxyurea (IC50: 100 μM). kinetic study on TM11, clarified its mode of action as a mixed inhibitor. A molecular docking study on TM6, TM11 and TM21, was performed and the results showed the main residues inside the active site of the enzyme. All TM1-TM53 were also studied in silico using molecular docking techniques to evaluate their potential to inhibit succinate dehydrogenase in comparison to fluxapyroxad as standard. Docking study revealed the high potential of TM1-TM53 as a fungicides.Conclusion: Obtained results exhibited the high activity of benzimidazole-acrylonitrile derivatives as urease inhibitors and their possible potential as fungicide agents. So, it will be beneficial to do more bioactivity investigation on this family of compounds.

Design, Synthesis, Acaricidal Activities, and Structure-Activity Relationship Studies of Oxazolines Containing Ether Moieties

To develop highly efficient and low cost acaricides, a series of 2,4-diphenyl-1,3-oxazolines containing an ether moiety at the para position of the 4-phenyl group were synthesized from different alcohols and phenols. The bioassay results showed that most of the compounds, especially the short-chain alkyl ethers, exhibited excellent acaricidal activity against both the larvae and the eggs of Tetranychus cinnabarinus. In particular, the n-propyl ether compound Ic possessed much better larvicidal activity (LC₅₀ = 0.0015 mg/L) and ovicidal activity (LC₅₀ = 0.0008 mg/L) than commercial acaricide etoxazole (LC₅₀ = 0.0145 and 0.02 mg/L for larvae and eggs, respectively). In addition, some compounds also exhibited insecticidal activity, especially compound Iw (4-CF₃-phenyl ether) showed higher mortality than etoxazole against Mythimna separata, Helicoverpa armigera, and Pyrausta nubilalis. Considering the high acaricidal activity and relatively low cost, Ic was worthy of further study as an acaricide agent. An alternative synthetic route for the large-scale synthesis of Ic was then studied.

Advancement of Phenoxypyridine as an Active Scaffold for Pesticides

Phenoxypyridine, the bioisostere of diaryl ethers, has been widely introduced into bioactive molecules as an active scaffold, which has different properties from diaryl ethers. In this paper, the bioactivities, structure-activity relationships, and mechanism of compounds containing phenoxypyridine were summarized, which may help to explore the lead compounds and discover novel pesticides with potential bioactivities.