Novel N-Alkylbenzimidazole-Ruthenium (II) complexes: Synthesis and catalytic activity of N-alkylating reaction under solvent-free medium

In this article, direct N-alkylation reactions of amines with alcohols derivatives have been investigated. For this purpose, a new series ruthenium (II) complexes bearing N-coordinated benzimidazole complexes with have been synthesized and fully characterized by elemental analysis, FT-IR, H-1 NMR and, C-13 NMR spectroscopies. Additionally, the structures of the complexes 2b and 2c have been confirmed by X-ray crystallography. Although the N-alkylating reaction is usually performed in toluene, the catalytic study of complexes 2a-d has carried out no additional solvent and alcohol acted both as solvent and reactant of alkylating by using a little excess of alcohols. Surprisingly, conversion and selectivity of amine product for alkylation reaction have been seen high in medium solvent-free relative to in toluene.