Half-sandwich ruthenium complexes with oxygen–nitrogen mixed ligands as efficient catalysts for nitrile hydration reaction

Abstract

Three ruthenium(II) p-cymene complexes containing oxygen–nitrogen mixed ligands [Ru(p-cymene)LCl] [HL=2-(4,5-dihydrooxazol-2-yl)phenol (2a); HL=2-(4,5-dihydrothiazol-2-yl)phenol (2b); HL=2-(5,6-dihydro-4H-1,3-oxazin-2-yl)phenol (2c)] have been synthesized and characterized. All half-sandwich ruthenium complexes were fully characterized by 1H and 13C NMR spectra, elemental analyses and infrared spectrometry. The molecular structure of ruthenium complex 2c was further confirmed by single-crystal X-ray diffraction methods. Furthermore, these half-sandwich ruthenium complexes are active catalysts for the hydration of nitriles to amides in the presence of sodium hydroxide in isopropanol.