Synthesis and structures of ruthenium–NHC complexes and their catalysis in hydrogen transfer reaction

Abstract

SummaryRuthenium complexes [Ru(L1)2(CH3CN)2](PF6)2 (1), [RuL1(CH3CN)4](PF6)2 (2) and [RuL2(CH3CN)3](PF6)2 (3) (L1= 3-methyl-1-(pyrimidine-2-yl)imidazolylidene, L2 = 1,3-bis(pyridin-2-ylmethyl)benzimidazolylidene) were obtained through a transmetallation reaction of the corresponding nickel–NHC complexes with [Ru(p-cymene)2Cl2]2 in refluxing acetonitrile solution. The crystal structures of three complexes determined by X-ray analyses show that the central Ru(II) atoms are coordinated by pyrimidine- or pyridine-functionalized N-heterocyclic carbene and acetonitrile ligands displaying the typical octahedral geometry. The reaction of [RuL1(CH3CN)4](PF6)2 with triphenylphosphine and 1,10-phenanthroline resulted in the substitution of one and two coordinated acetonitrile ligands and afforded [RuL1(PPh3)(CH3CN)3](PF6)2 (4) and [RuL1(phen)(CH3CN)2](PF6)2 (5), respectively. The molecular structures of the complexes 4 and 5 were also studied by X-ray diffraction analysis. These ruthenium complexes have proven to be efficient catalysts for transfer hydrogenation of various ketones.

New Organometallic Ruthenium(II) Compounds Synergistically Show Cytotoxic, Antimetastatic and Antiangiogenic Activities for the Treatment of Metastatic Cancer

“…Ruthenium‐NHC complexes Ru1 and Ru5 were synthesized according to the protocol [21] shown in Figure 1 B. The reaction of the in situ generated silver‐NHC complexes, a carbene transfer agent, with one equivalent of [Ru( p ‐cymene)Cl 2 ] 2 and NH 4 PF 6 in acetonitrile readily produced [RuL1(CH 3 CN) 4 ](PF 6 ) 2 ( Ru1 ) and [RuL2(CH 3 CN) 4 ](PF 6 ) 2 ( Ru5 ) in high yields (56–66 %).…”

“…Ruthenium-NHC complexes Ru1 and Ru5 weres ynthesized according to the protocol [21] shown in Figure 1B Motivated by the ease of compound synthesis, we further attempted toe xpand the library of ruthenium(II) derivatives. For this purpose, we reacted Ru1 or Ru5 with bidentate ligands (e.g.,2 ,2'-bipyridine (bpy), 5,5'-dimethyl-2,2'-bipyridine (dmbpy), and 1,10-phenanthroline (phen))i nr eflux acetonitrile.…”

Crystal structure of trans-tetrakis(acetonitrile-κN)bis(triphenylphosphine-κP)ruthenium(II) dihexafluorophosphate - dichloroform (1/2), C46H44Cl6F12N4P4Ru

“…Ruthenium complexes have been attracted a lot of interest because of their catalytic, biological and pharmaceutical properties [5][6][7]. Ruthenium complexes containing CH 3 CN ligands have been considered as good precursors to synthesize a large amount of Ru complexes with other donor ligands [8][9][10].…”

Nickel, Ruthenium, and Rhodium NCN-Pincer Complexes Featuring a Six-Membered N-Heterocyclic Carbene Central Moiety and Pyridyl Pendant Arms

“… Longer pendant arms allow for pincer coordination and a number of complexes I (M = Ru, Pd, Pt) have been described . Their benzimidazole analogues J are also well-known (M = Ru, Ni, Pd, Pt) . The nonpincer coordination chemistry of Group 11 and 12 metals with the ligands shown in complexes I has been extensively investigated, and these moieties have also been incorporated in tetradentate cyclophane ligands.…”