Synthesis of ruthenium(II) complexes derived from reduced imine ligands: As catalysts for transfer hydrogenation of ketones

•A series of neutral Ru(II) complexes derived from reduced imine ligands containing aromatic sulfonamide was synthesized.•The synthesized compounds were characterized by different methods such as NMR, FT-IR, and elemental analysis.•The complexes have been used as catalyst for the TH of p-substitute acetophenone derivatives.

N-[2-(benzylamino)phenyl]benzenesulfonamide derivatives (1–6) were successfully synthesized by the reaction of imine ligands derived from various N-(2-aminophenyl)benzenesulfonamides and NaBH4. Then, a series of N-coordinate Ru(II) arene complexes 7–12 were prepared from the reaction of [RuCl2(p-cymene)]2 with 1–6. The synthesized compounds were characterized by different methods such as NMR, FT-IR, and elemental analysis. 7–12 were used as catalysts for the transfer hydrogenation (TH) of ketones. At the same time, the effect of various bases such as NaOH, KOH, KOBut and Et3N as organic base were investigated in TH of ketones by 2-propanol as the hydrogen source. 7–12 showed good catalytic activity and so the effects of the different groups were also examined.

Graphical abstractA series of Ru(II) complexes derived from reduced imine ligands containing aromatic sulfonamide was synthesized and characterized by NMR, FT-IR and elemental analysis. And the [RuLCl2(p-cymene)] complexes used as catalysts for the transfer hydrogenation of ketones.Figure optionsDownload full-size imageDownload as PowerPoint slide