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Iodine‐Mediated Aryl C−H Amination for the Synthesis of Benzimidazoles and Pyrido[1,2‐ a ]benzimidazoles
Author(s) -
Lv Zhigang,
Liu Jing,
Wei Wei,
Wu Jie,
Yu Wenquan,
Chang Junbiao
Publication year - 2016
Publication title -
advanced synthesis and catalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.541
H-Index - 155
eISSN - 1615-4169
pISSN - 1615-4150
DOI - 10.1002/adsc.201600455
Subject(s) - chemistry , amination , benzimidazole , aryl , iodine , potassium carbonate , intramolecular force , combinatorial chemistry , imidazole , coupling reaction , organic chemistry , catalysis , alkyl
An intramolecular aryl C−H amination reaction has been achieved using molecular iodine as the sole oxidant for the synthesis of benzimidazole derivatives. The required substrates were readily prepared by addition or coupling of arylamines with the corresponding nitriles or aryl iodides. Iodine‐mediated oxidative cyclization of these substrates in the presence of potassium carbonate (K 2 CO 3 ) as base afforded the corresponding products in moderate to good yields. The transition metal‐free protocol presented here is insensitive to air and operationally simple. This versatile and eco‐friendly synthetic methodology is broadly applicable to a variety of N ‐aryl‐substituted amidines and pyridin‐2‐amines, and provides direct access to both 1 H ‐benzo[ d ]imidazole and pyrido[1,2‐ a ]benzimidazole derivatives from the corresponding precursors.