Design, Synthesis And Biological Activity Of (E)-Beta-Farnesene Analogues Containing Imidogen

In order to discover novel compounds with high-activity to control aphid, aphid alarm pheromone (E)-beta-farnesene (EBF) was chosen as lead compound and a series of EBF analogues containing imidogen were designed by replacing unstable conjugated double bonds of EBF with different aromatic ring. Nineteen EBF analogues were synthesized via two reaction routes of N-alkylation and reductive amination. Their structures were confirmed by H-1 NMR, C-13 NMR, IR and HRMS analysis. The bioassay and structure-activity relationship analysis were carried out. The result indicated that title compounds containing benzene or pyridine displayed obvious repellent activity against Myzus persicae (Sulzer). Especially, compounds 3g, 3l and 3m exhibited excellent repellent activity of 62.0%, 62.5% and 64.6% respectively. Moreover, the title compounds containing 1,3,4-thiadiazole ring showed certain insecticidal activity against M. persicae. In particular, the mortality rate of compounds 3i, 3l, 3r and 3s were 70.7%, 72.6%, 70.4% and 75.5% at a concentration of 200 ae g/ mL, which were higher than the lead EBF. However, compound 3a, in which the conjugated double bonds were replaced with butyl, showed obviously neither repellent nor aphicidal activity.