title: Gold(I)-catalyzed aminohalogenation of fluorinated N'-aryl-N-propargyl amidines for the synthesis of imidazole derivatives under mild conditions.
abstract: A procedure for the synthesis of fluorinated imidazole derivatives from propargyl amidines has been developed. Under gold(I) catalysis, propargyl amidines were converted into 5-fluoromethyl imidazoles in the presence of Selectfluor through a cascade cyclization/fluorination process. In contrast, imidazole-5-carbaldehydes were obtained in high yields when N-iodosuccinimide (NIS) was used as the halogenating reagent. The polarity of the solvent and light had significant impact on the formation of the carbaldehydes. These transformations showed excellent functional-group tolerance. An unfluorinated substrate with an electron-withdrawing group also underwent aminohalogenation to give the corresponding product in good yield. Mechanistic investigation revealed the general pathways of these transformations.
authors.affiliation: Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Science, 345 Lingling Road, Shanghai 200032, PR China.
authors.forename: Shan
authors.initials: S
authors.lastname: Li
authors.forename: Zhengke
authors.initials: Z
authors.lastname: Li
authors.forename: Yafen
authors.initials: Y
authors.lastname: Yuan
authors.forename: Yajun
authors.initials: Y
authors.lastname: Li
authors.forename: Lisi
authors.initials: L
authors.lastname: Zhang
authors.forename: Yongming
authors.initials: Y
authors.lastname: Wu