Ruthenium(II) 8-quinolinolates: Synthesis, characterization, crystal structure and catalysis in the synthesis of 2-oxazolines

Abstract

New octahedral ruthenium(II) complexes (1-4) have been synthesized from the reaction of ruthenium(II) precursors [RuHCl(CO)(EPh 3 ) 3 ] (E = P or As) with the bidentate Schiff base ligands, 2-((2,6-dimethylphenylimino)methyl)quinolin-8-ol (L 1 ) and 2-((2,6-diisopropylphenylimino)methyl)quinolin-8-ol (L 2 ) in ethanol. These complexes have been characterized by elemental analyses, IR, UV-Vis, 1 H, 13 C and 31 P NMR and ESI-Mass spectroscopy. The molecular structure of the complex [RuCl(CO)(PPh 3 ) 2 (L 2 )] (2) was determined by single-crystal X-ray diffraction, which reveals a distorted octahedral geometry around ruthenium(II) ion. The catalytic activity of the new complexes was evaluated for the condensation of nitriles with ethanolamine under solvent free conditions. The processes were operative with aromatic and heteroaromatic nitriles and tolerated several substitutional groups.The studies on the effect of substitution over ligands, coligands, reaction time, temperature and catalyst loading were carried out in order to find the best catalyst in this series of complexes and favorable reaction conditions. A probable mechanism for the catalytic condensation of nitrile has also been proposed. The catalyst was recovered and recycled up to five times without significant loss of its activity.

In Vitro Antiviral Activity of New Oxazoline Derivatives as Potent Poliovirus Inhibitors

“…The organic phase was washed with water (40 mL) and brine solution (40 mL), treated with Na 2 SO 4 , filtered, and evaporated under reduced pressure to give 0.28 g of 17 as a yellow solid (20% yield). The chemical, physical, analytical, and spectroscopic data of compound 17 are reported in literature …”

Crystal structure of 4-(1-phenylimidazo[1,5-a]pyridin-3-yl)benzoic acid (C20H14N2O2)

“…Heterocyclic compounds possessing both the imidazole and pyridines moieties are of great importance as ligands in inorganic synthesis [7]. The title compound is known to be present in the structures of some biologically active compounds, thus giving it some importance.…”

Crystal structure of bis{μ-(E)-2-[(2-oxidophenylimino)methyl]quinolin-8-olato-κ4O,N,N′,O′}bis[dibutyltin(IV)]

“…Meanwhile, in the title compound each ring is only fused to one another, giving rise to a more extended structure. Previously, representative elements (Sun et al, 2011), transition (Anitha et al, 2015;García-Santos et al, 2009;Yan et al, 2014) and lanthanide (Zhang et al, 2012(Zhang et al, , 2015 metal complexes of [(imino)methyl]quinolin-8-olato derivatives have been reported, and only in the case of the lanthanide complexes is the nitrogen atom of the imine group involved in the ligand coordination. So, to the best of our knowledge, the title compound is the first example of a [(imino)methyl]quinolin-8olato derivative with the ligand using the full possible denticity.…”