Synthesis, stability and insecticidal activity of 2‐arylstilbenes

Abstract

BACKGROUND: A chemical scaffold-hopping approach from known 3-hydroxyl-3-methylglutaryl-CoA (HMG-CoA) reductase inhibitors identified (E/Z)-2-arylstilbenes as novel insecticidal hits against two lepidopteran species, Spodoptera exigua and Trichoplusia ni. A structure-activity relationship (SAR) study of the aryl substituents and the E/Z conformations was carried out in an effort to improve insecticidal potency. RESULTS:A series of (E/Z)-2-arylstilbenes was prepared and separated to evaluate their insecticidal potency against lepidopterous species in diet-feeding assays. The results showed that the (Z)-2-arylstilbenes were more active than their corresponding (E)-isomers, and a stereoselective synthesis was utilized to expand the SAR of the (Z)-2-arylstilbenes. (Z)-4'-Fluoro-3 ′ -methyl-2-(2,4-difluorostyryl)-4-fluoro-5-methoxy-1,1 ′ -biphenyl was the most potent analog in this study with strong activity against S. exigua, T. ni, Helicoverpa zea, Plutella xylostella and Pseudoplusia includens.CONCLUSION: The (Z)-2-arylstilbenes were found to have strong insecticidal potency against five lepidopteran species. Ultimately, synthetic efforts could not improve insecticidal potency to commercial levels, and a lack of UV stability led to efforts being discontinued.

Fragmenlt Recombination Design, Synthesis, and Safener Activity of Novel Ester-Substituted Pyrazole Derivatives

“…One of the main techniques for designing and optimizing novel framework structures with the target biological activity is the fragment splicing method. Many instances of fragment splicing have been demonstrated; − for example, the design of the novel fungicide fluopyram was formed by splicing the fragments of flutolanil and fluopicolide (Scheme ). …”