Bioisosteric-Replacement-Driven Lead Optimization of Tyclopyrazoflor

A heterocyclic replacement strategy has been applied attempting to further optimize the biological properties of the new insecticide tyclopyrazoflor, a pyridinyl-pyrazole compound with excellent activity against sap-feeding insects recently discovered by Corteva. Our research program on this novel chemical class of insecticide was targeted to evaluate the importance of both the pyridyl and pyrazole moieties on the biological activity, properties, and structure-activity. Synthetic methodologies have been developed delivering our designed target compounds in moderate to good yields. In our attempt to rationalize the biological activity differences of tyclopyrazoflor analogues, a potential surface analysis based on a density functional theory (DFT) calculation and DFT-derived Multiwfn and VMD program model was performed. Furthermore, the SwissBioisostere online database was applied as a great source for inspiration for bioisosteric replacements.