The first used half sandwich ruthenium(II) complexes bearing benzimidazole moiety for N-alkylation of amines with alcohols

•N-substituted benzimidazoles (L) were prepared.•Half sandwich Ru-(II) complexes were synthesized and characterized.•All novel complexes first used as a catalyst for the N-alkylation reaction.

Half sandwich ruthenium(II) complexes were synthesized from [RuCl2(η6-p-cymene)]2 and N-substituted benzimidazole. All new compounds were characterized by elemental analysis, 1H NMR, 13C NMR, and IR spectroscopy. Aminoarenes were readily converted into secondary amines by the reaction at 150 °C with benzyl alcohol and in the presence of a catalytic amount of novel ruthenium complexes. All of [RuCl2(η6-p-cymene)(N-substituted benzimidazole)] complexes were the most effective catalyst for N-alklyation reaction using borrowing hydrogen methodology.

Graphical abstractN-Substituted benzimidazole and half sandwich ruthenium(II) complexes [RuCl2(η6-p-cymene)(N-substituted benzimidazole)] were synthesized and characterized by elemental analysis, 1H NMR, 13C NMR, and IR spectroscopy. All novel complexes first used as a catalyst for the N-alkylation of amines with alcohols. Figure optionsDownload full-size imageDownload as PowerPoint slide