10.1021/jo902160y.s001 Keiichi Hirano Keiichi Hirano Akkattu T. Biju Akkattu T. Biju Frank Glorius Frank Glorius Copper-Catalyzed Synthesis of 2-Unsubstituted, <i>N</i>-Substituted Benzimidazoles American Chemical Society 2009 intramolecular yield arylation benzimidazole utility sterically method Synthesi Me BenzimidazolesAn substituent Unsubstituted diisopropylphenyl formamidine unsubstituted 2009-12-18 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Copper_Catalyzed_Synthesis_of_2_Unsubstituted_i_N_i_Substituted_Benzimidazoles/2805580 An efficient copper-catalyzed intramolecular arylation of formamidines forming 2-unsubstituted benzimidazoles in excellent yields is reported. Sixteen examples bearing sterically demanding substituents on nitrogen like Mes, 2,6-diisopropylphenyl, or 2-<i>tert</i>-butylphenyl and tolerating various functional groups demonstrate the utility of this method.