Synthesis and Antifungal Bioactivity of Methyl 2-Methoxyimino- 2-{2-[(substituted benzylidene)aminooxymethyl]phenyl}acetate and 2-Methoxyimino-2-{2-[(substituted benzylidene)aminooxy- methyl]phenyl}-N-methylacetamide Derivatives

Comprehensive Overview of β-Methoxyacrylate Derivatives as Cytochrome bc1 Inhibitors for Novel Pesticide Discovery

β-Methoxyacrylate derivatives represent a new class of pesticides, which have attracted increasing attention owing to their unique structure, broad biological activity, and unique mechanisms of action. They inhibit mitochondrial respiration via preventing electron transfer at the Qo site of the cytochrome bc₁ complex and thus are identified as cyt bc₁ inhibitors. A variety of β-methoxyacrylate derivatives have been reported by many research groups for discovery of novel pesticides with improved expected activities. This review focuses on development of β-methoxyacrylate derivatives with great significance as pesticides such as fungicides, acaricides, insecticides, herbicides, and antiviral agents. In addition, the structure-activity relationships (SARs) of β-methoxyacrylate derivatives are summarized. Moreover, the cause of resistance to β-methoxyacrylate fungicides and some solutions are also introduced. Finally, the development trend of β-methoxyacrylate derivatives as pesticides is explored. We hope the review will give a guide to develop novel β-methoxyacrylate pesticides in the future.

Synthesis, Fungicidal Activity, Structure–Activity Relationship and Density Functional Theory Studies of Novel Oxime Ether Derivatives Containing 1-Aryl-3-Oxypyrazoles

A series of 16 oxime ether derivatives containing 1-aryl-3-oxypyrazoles were synthesised, and the structure of one of them, (E)-methyl 2-(2-({(1-(4-chlorophenyl)-1H-pyrazol-3-yl)-oxy}methyl)phenyl)-2-(methoxyimino)acetate was determined by X-ray diffraction crystallography. Preliminary bioassays indicated that some of these compounds exhibited very good fungicidal activities against Rhizoctonia solani, especially the ester 2-(2-({(1-(4-chlorophenyl)-1H-pyrazol-3-yl)-oxy}methyl)phenyl)-2-(methoxyimino)acetate, which displayed greater activity than control compound pyraclostrobin at a dosage of 0.1 μg mL-1. The relationship between structure and fungicidal activity was discussed. Density functional theory studies of the 3-methyl heterocyclic ester and the 4-chorophenyl heterocyclic N-methylamide were carried out and the results discussed in terms of the wide difference in fungicidal activity shown by each compound.

Synthesis, Crystal Structure, and Fungicidal activity of Novel 1-Aryl-3-Oxypyrazoles Containing a Z-Configuration Methyl 2-(Methoxyimino) Acetate Moiety

Six novel methyl( Z)-2-(4-{[(1-aryl-1 H-pyrazol-3-yl)oxy]methyl}phenyl) 2-(methoxyimino)acetate were synthesised by the reaction of 1-aryl-1 H-pyrazol-3-ols with methyl ( Z)-2-[4-(bromomethyl)phenyl]-2-(methoxyimino)acetate. The structure of methyl ( Z)-2-[4-({[1-(4-chlorophenyl)-1 H-pyrazol-3-yl]oxy}methyl)phenyl]-2-(methoxyimino)acetate was also determined by single-crystal X-ray diffraction analysis. A preliminary in vitro bioassay indicated that compounds 3-chlorophenyl, 4-chlorophenyl and 4-fluoro-3-(trifluoromethyl) derivatives exhibited moderate fungicidal activity against Rhizoctonia solani at a dosage of 10 μg mL-1.

Synthesis and fungicidal activity of novel chloro-containing 1-aryl-3-oxypyrazoles with an oximino ester or oximino amide moiety

Six novel chloro-containing 1-aryl-3-oxypyrazoles TMa–TMf with an oximino ester or an oximino amide moiety were prepared by the reaction of 1-aryl-1H-pyrazol-3-ols with benzyl bromide. Their structures were characterized by ¹H-NMR, ¹³C-NMR, IR, MS, and elemental analysis. A preliminary in vitro bioassay indicated that compounds TMa, TMe and TMf displayed excellent fungicidal activity against Rhizoctonia solani and could be used as potential lead compounds for further development of novel fungicides.