Palladium-Catalyzed Cyclization Reaction of Oxime Acetates and Aryl Iodides: Syntheses of 2-Imidazolines

A convenient one-pot synthesis of N-substituted amidoximes and their application toward 1,2,4-oxadiazol-5-ones

The first direct one-pot approach for the synthesis of N-substituted amidoximes from secondary amides or the intermediate amides has been developed. Through the Ph₃P–I₂-mediated dehydrative condensation, a variety of N-aryl and N-alkyl amidoximes (R¹(C Created by potrace 1.16, written by Peter Selinger 2001-2019 ]]> NOH)NHR², where R¹ or R² = aryl, alkyl, or benzyl) were readily afforded under mild conditions and short reaction times. The synthetic application of the obtained amidoximes has also been demonstrated through the formation of 1,2,4-oxadiazolones via base-mediated carbonylative cyclization with 1,1′-carbonyldiimidazole.

Ph₃P–I₂ mediated one-pot synthesis of N-substituted amidoximes via imidoyl iodide was developed. The synthesis of 1,2,4-oxadiazol-5-ones was also demonstrated.