Catalytic applications of transition metal complex with N-heterocyclic carbene ligands

Abstract

A Ru (II) pNHC metal complex, [Ru(NNCH )(PPh3)2Cl]Cl, has been synthesized by transmetallation reaction of silver complex bearing NHC ligand precursor, 6-(1H benzo[d]imidazol-1-yl)-N-(pyridin-2-yl)-N-(p- tolyl)pyridin-2-amine as reported in previous research article of our lab. Metal precursor [RuCl2(PPh3)3] was synthesized by RuCl3·3H2O using literature procedure. This complex was previously reported in our lab. All the structures of the synthesized ligand and the complex have been characterized by mass spectrometry, 1H, and 13C NMR, which clearly matches with the previous data. The catalytic activity of NHC−Ru(II) complex was investigated in the N-alkylation reaction of aniline derivatives with benzyl alcohols to form N-benzyl amine. In this report, Ru(II) complex in N-alkylation reactions was optimized with different substrates, and considerable results were obtained. All obtained products were synthesized under optimized conditions and characterized by 1H and 13C NMR data. Conversion percentages have been determined by NMR spectroscopy.