Ruthenium(II) η6-arene complexes containing a dinucleating ligand based on 1,8-naphthyridine

• New bimetallic ruthenium complexes with a dinucleating ligand synthesized.
• X-ray crystallographic determination provided the coordination detail of metal centers.
• The di–ruthenium complex is active for oxidative coupling of 1,2-diols or 1,2-aminoalcohol with o-phenylenediamines leading to quinoxalines.

Ruthenium arene complexes, [(η6-p-cymene)2Ru2(L)Cl2](PF6)2 [3b, L = 2, 7-bis(di-2-pyridinyl)-1,8-naphthyridine] and [(η6-p-cymene)Ru(L′)Cl](PF6) [4, L′ = tri(2-pyridinyl)amine], were synthesized and characterized by spectroscopic and analytical techniques. The molecular structure of [(η6-p-cymene)2Ru2(L)Cl2]Cl2 (3a) was further determined by single-crystal X-ray analysis. The use of these ruthenium complexes as pre-catalysts for oxidative coupling of 1,2-diols/1,2-aminoalcohol with o-phenylenediamines leading to quinoxalines was investigated. Complex 3b appeared to be a good catalyst for this transformation.

A dimetallic ruthenium complex with a 1,8-naphthyridine-based multidentate was synthesized and characterized. This complex appeared to be a good catalyst for oxidative coupling of 1,2-diols/1,2-aminoalcohol with o-phenylenediamines leading to quinoxalines.Figure optionsDownload as PowerPoint slide