Ruthenium complexes of phosphine-aminophosphine ligands

Ruthenium complexes of phosphinoferrocenylaminophosphine ligands (BoPhoz™ ligands) have been prepared by combining the ligands with tris(triphenylphosphine)ruthenium dichloride and precipitating the complexes. The optimal species exhibit high enantioselectivities for the asymmetric hydrogenation of functionalized ketones, particularly β-ketoesters.     

Ruthenium complexes containing aromatic thioamides

Summary Reaction of aromatic thioamides, LH, withcis-[Ru(CO)₂Cl₂] yieldscis-[Ru(CO₂)Cl₂LH]. The complexes have been characterised by analytical, i.r., electronic and n.m.r. spectral and magnetic measurements. All the Ru^II diamagnetic complexes have been assigned distorted octahedral geometry.     

Ruthenium complexes of thiaporphyrin and dithiaporphyrin

Successful synthesis and characterization of the six-coordinated complex [Ru(STTP)(CO)Cl] (1; STTP = 5,10,15,20-tetratolyl-21-thiaporphyrinato) allowed the development of the coordination chemistry of ruthenium-thiaporphyrin through dechlorination and metathesis reactions. Accordingly, [Ru(II)(STTP)(CO)X] (X = NO(3)(-) (2), NO(2)(-) (3), and N(3)(-) (4)) was synthesized and analyzed by single-crystal X-ray structural determination and NMR, UV-vis, and FT-IR spectroscopic methods. An independent reaction of STPPH and [Ru(COD)Cl(2)] led to [Ru(III)(STTP)Cl(2)] (5), which possessed a higher-valent Ru(III) center and exhibited good stability in the solution state. This stability allowed reversible redox processes in a cyclic voltammetric study. Reactions of [Ru(S(2)TTP)Cl(2)] (S(2)TTP = 5,10,15,20-tetratolyl-21,23-dithiaporphyrinato) with AgNO(3) and NaSePh, also via the metathesis strategy, resulted in novel dithiaporphyrin complexes [Ru(II)(S(2)TTP)(NO(3))(2)] (6) and [Ru(0)(S(2)TTP)(PhSeCH(2)SePh)(2)] (7), respectively. The structures of 6 and 7 were corroborated by X-ray crystallographic analyses. Complex 7 is an unprecedented ruthenium(0)-dithiaporphyrin with two bis(phenylseleno)methanes as axial ligands. A comparison of the analyses of the crude products from reactions of NaSePh and CH(2)Cl(2) with or without [Ru(S(2)TTP)Cl(2)], further supported by UV-vis spectral changes under stoichiometric reactions between [Ru(S(2)TTP)Cl(2)] and NaSePh, suggested a reaction sequence in the order of (1) formation of a putative [Ru(II)(S(2)TTP)(SePh)(2)] intermediate, followed by (2) the concerted formation of PhSe-CH(2)Cl and simultaneously a reduction of Ru(II) to Ru(0) and finally (3) nucleophilic substitution of PhSeCH(2)Cl by excess PhSe(-), resulting in PhSeCH(2)SePh, which readily coordinated to the Ru(0) and completed the formation of bis(phenylseleno)methane complex 7.     

Ruthenium complexes as protein kinase inhibitors

[reaction: see text] Replacing complex natural products with simple metal complexes could lead to a new class of metallopharmaceuticals in which the metal center plays mainly a structural role. A strategy is introduced for the creation of ruthenium complex-based protein kinase inhibitors 1 (X = CO or CH(2)), morphed out of the class of indolocarbazole inhibitors with the alkaloid staurosporine as its most prominent member.     

Ruthenium biimidazole complexes as anion receptors

The behavior of the compound [RuCl(cym)(H2biim)][BAr'4] (cym = eta6-para-isopropylmethylbenzene, Ar' = 3,5-bis(trifluoromethyl)phenyl), synthesized from [[RuCl(cym)]2(mu-Cl)2], H2biim and NaBAr'4, has been studied as a receptor of anions both in solution and in the solid state.     

Ruthenium nitrosyl complexes in nitric acid solutions

Nine nitrosyl ruthenium complexes have been separated and identified in aqueous solutions of nitric acid. The separation method was low temperature, gradient elution, reverse phase partition chromatography using tri-n-butyl phosphate on a kiesel gel 60 support using ¹⁰⁶Ru labelled complexes in the nitric acid phase. The identification of the complexes was deduced from the relationships between the products of aquation and nitration and paper chromatography using both methyl-iso-propyl ketone and nitric acid-acetone elutions. The proportion of each complex at equilibrium in various concentrations of nitric acid have been measured. The rates of nitration in 10 M nitric acid, and of equation in 0.45 M nitric acid have been determined at 0°C.     

Ruthenium complexes with chiral tetradentate imino-sulfoxide ligands

Treatment of 2-(methylsulfinyl)benzaldehyde (1) with ethylenediamine or (1R,2R)-(-)-1,2-diaminocyclohexane afforded N,N'-bis[2-(methylsulfinyl)benzylidene]ethylenediamine (L(1)) or (1R,2R)-N,N'-bis[2-(methylsulfinyl)benzylidene]-1,2-cyclohexanedia mine (L(2)), respectively. Lithiation of 2-bromobenzaldehyde diethylacetal with n-BuLi/TMEDA followed by reaction with (1R,2S,5R)-(-)-menthyl-(S)-p-toluenesulfinate afforded 2-(S)-(p-tolylsulfinyl)benzaldehyde diethyl acetal (2). Deprotection of 2 with pyridinium tosylate followed by condensation with ethylenediamine, (1R,2R)-(-)-diaminocyclohexane, or (S,S)-(+)-diaminocyclohexane afforded N,N'-bis[2-(S)-(p-tolylsulfinyl)benzylidene]ethylenediamine (L(3)), (1R,2R)-N,N'-bis[2-(S)-(p-tolylsulfinyl)benzylidene]-1,2-cyclohexanediamine ((R,R)-L(4)), or (S,S)-N,N'-bis[2-(S)-(p-tolylsulfinyl)benzylidene]-1,2-cyclohexanediamine ((S,S)-L(4)), respectively. Treatment of [Ru(PPh(3))(3)Cl(2)] with L afforded trans-[Ru(L)Cl(2)] [L = L(1) (3), L(2) (4), L(3) (5), (R,R)-L(4) ((R,R)-6), (S,S)-L(4) ((S,S)-6)]. The X-ray structures of (S(S),R(S))-4, (R,R)-6, and (S,S)-6 have been determined. The average Ru-N, Ru-S, and Ru-Cl distances in (S(S),R(S))-4 are 2.063, 2.2301, and 2.4039 A, respectively. The corresponding distances in (R,R)-6 are 2.071, 2.256, and 2.411 A, and those in (S,S)-6, 2.058, 2.2275, and 2.3831 A. Compound 3 exhibited a reversible Ru(III/II) couple at 0.56 V vs Cp(2)Fe(+/0) in CH(2)Cl(2). Treatment of 3 with AgNO(3) in water afforded the aqua compound trans-[Ru(L(1))Cl(H(2)O)][PF(6)] (7), which has been characterized by X-ray crystallography. The Ru-Cl, Ru-O, average Ru-N, and average Ru-S distances in 7 are 2.3733(6), 2.1469(16), 2.071, and 2.2442 A, respectively. Treatment of 3 with AgNO(3) followed by reaction with PPh(3) afforded [Ru(L(1))(PPh(3))(2)][PF(6)](2) (8). Treatment of [Os(PPh(3))(3)Cl(2)] with L(1) resulted in deoxygenation of one sulfoxide group of L(1) and formation of [Os(L(5))Cl(2)(PPh(3))] (9) (L(5) = N-[2-(methylsulfinyl)benzylidene]-N'-[2-(methylthio)benzylididene]ethylenediamine), which has been characterized by X-ray crystallography. The average Os-S(O), Os-N(trans to P), Os-N(trans to S), Os-P, and Os-Cl distances are 2.1931, 2.085, 2.175, 2.3641, and 2.4266 A, respectively.     

Ruthenium bis(phosphinite) pincer complexes

Resorcinol-based ruthenium bis(phosphinite) complexes were synthesized. Complexes RuCl(CO)[2,6-(Bu^t ₂PO)₂C₆H₃] (9) and RuH(CO)[2,6-(Bu^t ₂PO)₂C₆H₃] (10) were obtained by cyclometallation of 1,3-(Bu^t ₂PO)₂C₆H₃ with RuCl₂(DMSO)₄ in 2-methoxyethanol in the presence of Hünig’s base. The interconversion of complexes 9 and 10 was studied. The addition of carbon monoxide to complexes 9 and 10 yielded 18e adducts, RuCl(CO)₂[2,6-(Bu^t ₂PO)₂C₆H₃] (11) and RuH(CO)₂[2,6-(Bu^t ₂PO)₂C₆H₃] (12), respectively. In the case of complex 9, this reaction is reversible. Reaction of complex 10 with trifluoroacetic acid resulted in complex Ru(CF₃COO)(CO)[2,6-(Bu^t ₂PO)₂C₆H₃] (13), which reacted with carbon monoxide to give complex Ru(CF₃COO)(CO)₂[2,6-(Bu^t ₂PO)₂C₆H₃] (14). Based on the IR spectral data, the TFA ligand in complexes 13 and 14 is bound in a bi- and monodentate fashion, respectively. The structure of compound 9 was determined by X-ray diffraction analysis.     

Ruthenium piano-stool complexes bearing imidazole-based PN ligands

A variety of piano-stool complexes of cyclopentadienyl ruthenium(II) with imidazole-based PN ligands have been synthesized starting from the precursor complexes [CpRu(C₁₀H₈)]PF₆, [CpRu(NCMe)₃]PF₆ and [CpRu(PPh₃)₂Cl]. PN ligands used are imidazol-2-yl, -4-yl and -5-yl phosphines.Depending on the ligand and precursor different types of coordination modes were observed; in the case of polyimidazolyl PN ligands these were κ¹P-monodentate, κ²P,N-, κ²N,N- and κ³N,N,N- chelating and μ-κP:κ²N,N-brigding. The solid-state structures of [CpRu(1a)₂Cl ]·H₂O (5^.H₂O) and [{CpRu(μ-κ²-N,N-κ’¹-P-2b)}₂](C₆H₅PO₃H)₂(C₆H₅PO₃H₂)_2, a hydrolysis product of the as well determined [{CpRu(2b)}₂](PF₆)₂^.2CH₃CN (7b^.2CH₃CN) were determined (1a = imidazol-2-yldiphenyl phosphine, 2b = bis(1-methylimidazol-2-yl)phenyl phosphine, 3a = tris(imidazol-2-yl)phosphine). Furthermore, the complexes [CpRu(L)₂]PF₆ (L = imidazol-2-yl or imidazol-4-yl phosphine) have been screened for their catalytic activity in the hydration of 1-octyne.     

Ruthenium dihydride complexes as enyne metathesis catalysts

Ruthenium–catalyzed enyne metathesis is a reliable and efficient method for the formation of 1,3-dienes, a common structural motif in synthetic organic chemistry. The development of new transition-metal complexes competent to catalyze enyne metathesis reactions remains an important research area. This report describes the use of ruthenium (IV) dihydride complexes with the general structure RuH₂Cl₂(PR₃)₂ as new catalysts for enyne metathesis. These ruthenium (IV) dihydrides have been largely unexplored as catalysts in metathesis-based transformations. The reactivity of these complexes with 1,6 and 1,7-enynes was investigated. The observed reaction products are consistent with the metathesis activity occurring through a ruthenium vinylidene intermediate.     

Ruthenium,rhodium and palladium complexes of pyridines

Summary The syntheses, chemical reactivity, physicochemical properties and applications in solar energy conversion and storage of ruthenium, rhodium and palladium complexes of pyridines are described.     

Ruthenium(III) ion complexes with nucleotides

Summary Complexes of adenosine-5-monophosphate (5-AMP), guanosine-5-monophosphate (5-GMP), inosine-5-monophosphate (5-IMP) and cytidine-5-monophosphate (5-CMP) with ruthenium trichloride have been prepared and studied by i.r. spectroscopy, diffuse reflectance spectra and magnetochemical measurements.All complexes are probably polymeric as indicated by their insolubility in polar solvents.The i.r. spectra suggest that the ruthenium(III) ion interacts with the ligands through N(7) of the purine mononucleotides and through N(3) of the pyrimidine mononucleotide from one side and with the phosphate group of another mononucleotide molecule from another side. The formation of hydrogen bonds reinforces the interaction.The complexes have normal magnetic moments close to the spin-only value. The electronic spectra confirm their octahedral structure.     

Ruthenium and rhodium nitrosyl complexes containing dichalcogenoimidodiphosphinate ligands

Interaction of [Ru(NO)Cl₃(PPh₃)₂] with K[N(R₂PS)₂] in refluxing N,N-dimethylformamide afforded trans-[Ru(NO)Cl{N(R₂PS)₂}₂] (R = Ph (1), Prⁱ (2)). Reaction of [Ru(NO)Cl₃(PPh₃)₂] with K[N(Ph₂PSe)₂] led to formation of a mixture of trans-[Ru(NO)Cl{N(Ph₂PSe)₂}₂] (3) and trans-[Ru(NO)Cl{N(Ph₂PSe)₂}{Ph₂P(Se)NPPh₂}] (4). Reaction of Ru(NO)Cl₃ · xH₂O with K[N(Ph₂PO)₂] afforded cis-[Ru(NO)(Cl){N(Ph₂PO)₂}₂] (5). Treatment of [Rh(NO)Cl₂(PPh₃)₂] with K[N(R₂PQ)₂] gave Rh(NO){N(R₂PQ)₂}₂] (R = Ph, Q = S (6) or Se (7); R = Prⁱ, Q = S (8) or Se (9)). Protonation of 8 with HBF₄ led to formation of trans-[Rh(NO)Cl{HN(Prⁱ₂PS)₂}₂][BF₄]₂ (10). X-ray diffraction studies revealed that the nitrosyl ligands in 2 and 4 are linear, whereas that in 9 is bent with the Rh–N–O bond angle of 125.7(3)°.     

Ruthenium dihydrogen complexes with wide bite angle diphosphines

The wide bite angle diphosphines homoxantphos (10,11-dihydro-4,5,-bis(diphenylphosphino)dibenzo[b,f]oxepine), sixantphos (4,6-bis(diphenylphosphino)-10,10-dimethylphenoxasilin), and thixantphos (2,8-dimethyl-4,6-bis(diphenylphosphino)phenoxathiin) were used to prepare cis[MH(2)(diphosphine)(2)] complexes (1a-f) by reaction of [Ru(cod)(cot)] (cod = cyclo-octa-1,5-diene, cot = cyclo-octa-1,3,5-triene) with 2 equiv of the diphosphine under dihydrogen pressure. The electronic properties of the thixantphos ligand were varied. Complexes 1a-f can be protonated with HBF(4) or CF(3)COOH to yield hydrido(dihydrogen) complexes cis[MH(H(2))(diphosphine)(2)](+) (2a-f), which were characterized by VT (variable temperature) NMR and T(1) measurements. These complexes show fast hydrogen atom exchange between the eta(2)-H(2) and the terminal hydride at all temperatures studied. They are thermally unstable toward dihydrogen loss yielding the cationic monohydride complexes cis[MH(diphosphine)(2)](+) (3a-f). Coordination of the eta(2)-H(2) is dominated by sigma --> d donation, and hence, the H-H distance is hardly influenced by the electronic properties of the ligands.     

Ruthenium naphthalene complexes with a carboxy-substituted cyclopentadienyl ligand

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Ruthenium complexes of analogues of the antitumor antibiotic streptonigrin

The complexes Ru(L1-CH3)(CO)3Cl, RuL2(CO)2Cl2, and RuL3(CO)2Cl2 (L1= 6-methoxy-5,8-quinolinedione, L2 = 7-amino-6-methoxy-5,8-quinolinedione, L3 = 6,6'-dimethoxycarbonyl-2,2'-bipyridine) were prepared by reaction of L1-L3 with the tricarbonyldichlororuthenium(II) dimer. L1-L3 act as bidentates through the ortho oxygen atoms, the pyridyl nitrogen and the adjacent quinone oxygen, and the bipyridyl nitrogens, respectively. RuL3(CO)2Cl2 is characterized by X-ray crystallography. 15N NMR correlation spectra give upfield shifts of around 60 ppm for the pyridyl nitrogens that are coordinated to the metal, while 13C NMR correlation spectra give a downfield shift of 10 ppm for the quinone carbonyl group that is coordinated to the metal. The electrochemistry of RuL2(CO)2Cl2 is examined, and the implications for the formation of metal complexes of the antitumor antibiotic streptonigrin, which cleaves DNA in the presence of metal ions, are discussed.     

Ruthenium(II) complexes in polymerised bicontinuous microemulsions

Novel polymerised bicontinuous microemulsions can provide unique microenvironments for some functional molecules of scientific interests and practical applications.     

Ruthenium amino carboxylate complexes as asymmetric hydrogen transfer catalysts

The synthesis and characterization of optically active amino carboxylate complexes of formula [(η(6)-arene)Ru(Aa)Cl] (arene = C(6)H(6), C(6)Me(6), Aa = amino carboxylate) as well as those of the related trimers [{(η(6)-arene)Ru(Aa)}(3)][BF(4)](3) are reported. Trimerization takes place with chiral self-recognition: only diastereomers equally configured at the metal, R(Ru)R(Ru)R(Ru) or S(Ru)S(Ru)S(Ru), are detected. The crystal structures of the complexes [(η(6)-C(6)H(6))Ru(Pip)Cl] and [{(η(6)-C(6)Me(6))Ru(Pro)}(3)][BF(4)](3) have been determined by X-ray diffraction methods. Both types of complexes catalyse the hydrogen transfer reaction from 2-propanol to ketones with moderate enantioselectivity (up to 68% ee). The enantiodifferentiation achieved can be accounted for by assuming that Noyori's bifunctional mechanism is operating.     

Ruthenium(II) carbonyl complexes containing tetradentate Schiffbases

Ruthenium(II) carbonyl complexes of general formula [Ru(CO)(B)(L)] [where B = PPh3, pyridine (py), piperidine (pip); L = the dianionic tetradentate Schiff bases derived from the condensation of acetylacetone or benzoylacetone with ethylenediamine, propylenediamine or trimethylenediamine] have been synthesised by reacting [RuHCl(CO)(PPh3)2(B)] (B = PPh3, py or pip) with bis(acetylacetone)ethylenediimine, bis(acetylacetone)propylenediimine, bis(acetylacetone)trimethylenedi- imine, bis(benzoylacetone)ethylenediimine, bis(benzoylacetone)propylenediimine or bis(benzoylacetone)trimethylenediimine. The complexes were characterised onthe basis of elemental analyses, i.r., electronic and 1H- and 31P{1H}-n.m.r. spectral studies. This revised version was published online in June 2006 with corrections to the Cover Date.