Viktor A. Zapol’skii

Chemistry of polyhalogenated nitrobutadienes, 8: Nitropolychlorobutadienes—Precursors for insecticidal neonicotinoids

Nitropolychlorobutadienes are valuable precursors for highly functionalized acyclic or (hetero)cyclic compounds. In this 8th part of our synthetically oriented series we focus on the application of these versatile starting materials in the synthesis of analogs of the heterocyclic insecticides imidacloprid and thiacloprid, and the acyclic counterpart clothianidin. In addition to the main synthetic part, leading to imidazolidines or oxazolidines, further promising types of compounds derived by subsequent chemical modifications, are introduced. Most of the new compounds show high insecticidal activity.

Chemistry of polyhalogenated nitrobutadienes, 10: Synthesis of highly functionalized heterocycles with a rigid 6-amino-3-azabicyclo[3.1.0]hexane moiety

Summary The nitropolychlorobutadienes 3, 4 are valuable building blocks for various amination and successive heterocyclization products. Nucleophilic substitution reactions of the partially protected, bioactive amines 1, 2 with either vinyl, imidoyl or carbonyl chlorides result in the formation of the enamines 11, 12, 13, 16, 25, the amidine 6, and the amides 20, 21, respectively. In the following, cyclization to the highly functionalized pyrazoles 27, 28, pyrimidine 26 and pyridopyrimidine 24 succeeded. Deprotection of 21, 12 and 28 proved to be only partially feasible.