1021397-53-4Relevant academic research and scientific papers
Iodine-Mediated Aryl C?H Amination for the Synthesis of Benzimidazoles and Pyrido[1,2-a]benzimidazoles
Lv, Zhigang,Liu, Jing,Wei, Wei,Wu, Jie,Yu, Wenquan,Chang, Junbiao
, p. 2759 - 2766 (2016)
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 (K2CO3) 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 1H-benzo[d]imidazole and pyrido[1,2-a]benzimidazole derivatives from the corresponding precursors. (Figure presented.).
C-H functionalization/C-N bond formation: Copper-catalyzed synthesis of benzimidazoles from amidines
Brasche, Gordon,Buchwald, Stephen L.
, p. 1932 - 1934 (2008/12/22)
(Chemical Equation Presented) Copper closes the ring: Benzimidazoles are synthesized from amidines through a copper-catalyzed C-H functionalization/ C-N bond-forming process. The method tolerates a broad range of functional groups and provides the benzimidazoles in up to 89% yield. Best results are obtained by using 15 mol% Cu(OAc)2, 2-5 equivalents of HOAc as additive, and oxygen as the stoichiometric reoxidant (see scheme).
