Ruthenium(II) carbonyl complexes bearing quinoline-based NNO tridentate ligands as catalyst for one-pot conversion of aldehydes to amides and o-allylation of phenols

Abstract

Six new octahedral ruthenium(II) carbonyl complexes having the general molecular formula [RuCl(CO)(B)L1–2] (B=PPh3, AsPh3 or py; L1–2=quinoline based NNO ligand) were synthesized. The quinoline based ligands behave as monoanionic tridentate donor and coordinated to ruthenium via ketoenolate oxygen, azomethine nitrogen and quinoline nitrogen. The composition of the complexes has been established by elemental analysis and spectral methods (FT-IR, electronic, 1H NMR, 13C NMR, 31P NMR and ESI-Mass). The complexes were used as efficient catalysts for one-pot conversion of various aldehydes to their corresponding primary amides in presence of NH2OH·HCl and NaHCO3. The effect of catalyst loading and reaction temperature on catalytic activity of the ruthenium(II) carbonyl complexes were also investigated. The synthesized complexes also possess good catalytic activity for the o-allylation of phenols in the presence of K2CO3 under mild conditions. The complexes afforded branched allyl aryl ethers according to a regioselective reaction.