First discovery of pimprinine derivatives and analogs as novel potential herbicidal, insecticidal and nematicidal agents

Pimprinine and streptochlorin are indole natural products produced by many species of organisms, and they are reported to possess a wide range of biological activities, such as anticancer, antiviral, antifungal activity and so on. In this study, three series of pimprinine derivatives or analogs were efficiently synthesized under the optimized methods. Biological assays conducted at Syngenta firstly indicated the pimprinine derivatives or analogs possessed potential herbicidal and insecticidal activity, and this is highlighted by compounds 21g, 21h, 21i, 21j, 21l, 22h, 22i and 23h, they possessed significant biological activity as well as broad spectrum. Meanwhile, compounds with benzothiophene-oxazole core (21h, 22h and 23h), showed effective nematicidal activity in primary screening. Compounds 21g and 21i were identified as the most promising lead structures for further study. (C) 2020 Elsevier Ltd. All rights reserved.