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Gold(I)‐Catalyzed Aminohalogenation of Fluorinated N ′‐Aryl‐ N ‐Propargyl Amidines for the Synthesis of Imidazole Derivatives under Mild Conditions
Author(s) -
Li Shan,
Li Zhengke,
Yuan Yafen,
Li Yajun,
Zhang Lisi,
Wu Yongming
Publication year - 2013
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201202402
Subject(s) - propargyl , selectfluor , imidazole , chemistry , reagent , catalysis , aryl , yield (engineering) , combinatorial chemistry , organic chemistry , medicinal chemistry , solvent , alkyl , materials science , metallurgy
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.