15529-49-4Relevant academic research and scientific papers
Selective double bond isomerization of allyl phenyl ethers catalyzed by ruthenium metal complexes
Sharma, Sumeet K.,Srivastava, Vivek K.,Jasra, Raksh V.
, p. 200 - 209 (2006)
The RuCl2(PPh3)3 and RuCl 3(AsPh3)2·CH3OH complex catalysts were studied for the double bond isomerization of methyl chavicol and eugenol in the polar aprotic (DMSO, acetonitrile), polar protic (ethanol, methanol, n-propanol, iso-propanol, n-butanol, iso-butanol, n-hexanol) and non-polar (benzene, toluene, n-hexane, cyclohexane, tetrahydrofuran) solvents. The highest conversion of methyl chavicol (99.7%) with 95.4% selectivity of trans-anethole was observed in ethanol using RuCl2(PPh 3)3 catalyst. However, 94.2% conversion of methyl chavicol with 98.6% selectivity of trans-isomer was observed using methanol as a solvent in RuCl3(AsPh3)2·CH3OH. The kinetics of isomerization of methyl chavicol and eugenol using RuCl 2(PPh3)3 and RuCl3(AsPh 3)2·CH3OH catalysts in ethanol or methanol involving the effect of substrate concentrations, catalyst amount, solvents and temperature on the initial rate of reaction was studied in details. The initial rates of reaction were observed to increase on increasing the initial concentrations of methyl chavicol, eugenol and catalysts. However, the initial rate of reaction decreased on increasing the solvent concentration. Activation energies for the isomerization of methyl chavicol were calculated using RuCl2(PPh3)3 and RuCl 3(AsPh3)2·CH3OH catalysts and were found to be 4.3 and 6.0 kJ/mol, respectively. Activation energy for the isomerization of eugenol was found to be 6.9 kJ/mol using RuCl 2(PPh3)3 complex catalyst. The RuCl 2(PPh3)3 complex was recycled five times for the isomerization of methyl chavicol and eugenol.
Thiosemicarbazonates of ruthenium(II): Crystal structures of [Bis(triphenylphosphine)][bis(N-phenyl-pyridine-2-carbaldehyde thiosemicarbazonato)]ruthenium(II) and [Bis(diphenylphosphino)butane] [bis(salicylaldehyde thiosemicarbazonato)]ruthenium(II)
Lobana, Tarlok S.,Bawa, Gagandeep,Butcher, Ray J.,Liu, Chen W.
, p. 355 - 360 (2009)
Reaction of RuCl2(PPh3)3 with N-Phenyl-pyridine-2-carbaldehyde thiosemicarbazone (C5H 4N-C2(H)=N3-N2H-C 1(=S)-N1HC6H5, Hpyt
Ruthenium complexes of diphenylphosphino derivatives of carboxylic amides: Synthesis and characterization of bidentate P,N- and P,O-chelate ligands and their reactivity towards [RuCl2(PPh3)3]
Gericke, Robert,Wagler, J?rg
, p. 134 - 141 (2016)
The carboxylic amides N-methylbenzamide (HLa), phthalimidine (HLb) and pyridine-2-one (HLc) were diphenylphosphino-functionalized (with ClPPh2and a base, n-BuLi for HLa, triethylamine for HLb and HLc) to yield the N-PPh2derivatives o
Synthesis and spectroelectrochemical studies of mixed heteroleptic chelate complexes of ruthenium(II) with 1,8-bis(2-pyridyl)-3,6-dithiaoctane (pdto) and substituted 1,10-phenanthrolines
Ortiz-Frade, Luis A.,Ruiz-Ramirez, Lena,Gonzalez, Ignacio,Marin-Becerra, Armando,Alcarazo, Manuel,Alvarado-Rodriguez, Jose G.,Moreno-Esparza, Rafael
, p. 1825 - 1834 (2003)
Reaction of dichlorotris(triphenylphosphine) ruthenium(II) [RuCl2(PPh3)3] with 1,8-bis(2-pyridyl)-3,6-dithiaoctane (pdto), a (N2S2) tetradentate donor, yields a new compound [Ru(pdto)(PPh3)Cl]Cl (1), which has been fully characterized. 1H and 31P NMR studies of 1 in acetonitrile at several temperatures show the substitution of both coordinated chloride and triphenylphosphine with two molecules of acetonitrile, as confirmed by the isolation of the complex [Ru(pdto)(CH3CN)2]Cl2 (2). Cyclic voltammetric and spectroelectrochemical techniques allowed us to determine the electrochemical behavior of compound 1. The substitution of the chloride and triphenylphosphine by acetonitrile molecules in the Ru(II) coordination sphere of compound 1 was also established by electrochemical studies. The easy substitution of this complex led us to use it as starting material to synthesize the substituted phenanthroline coordination compounds with (pdto) and ruthenium(II), [Ru(pdto)(4,7-diphenyl-1,10-phenanthroline)]Cl2· 4H2O (3), [Ru(pdto)(1,10-phenanthroline)]Cl2·5H2O (4), [Ru(pdto)(5,6-dimethyl-1,10-phenanthroline)]Cl2· ·5H2O (5), [Ru(pdto)- (4,7-dimethyl-1,10-phenanthroline)]Cl2·3H2O (6), and [Ru(pdto)(3,4,7,8-tetramethyl-1,10-phenanthroline)]Cl2 ·4H2O (7). These compounds were fully characterized, and the crystal structure of 4 was obtained. Cyclic voltammetric and spectroelectrochemical techniques allowed us to determine their electrochemical behavior. The electrochemical oxidation processes in these compounds are related to the oxidation of ionic chlorides, and to the reversible transformation from RU(II) to Ru(III). On the other hand, a single reduction process is associated to the reduction of the substituted phenanthroline in the coordination compound. The E1/2 (phen/phen-) and E1/2 (RuII/RuIII) for the compounds (3-7) were evaluated, and, as expected, the modification of the substituted 1,10-phenanthrolines in the complexes also modifies the redox potentials. Correlations of both electrochemical potentials with pKa of the free 1,10-phenathrolines, λmax MLCT transition band, and chemical shifts of phenanthrolines in these complexes were found, possibly as a consequence of the change in the electron density of the Ru(II) and the coordinated phenanthroline.
Ruthenium(II) ammine and hydrazine complexes with [N(Ph2PQ)2]- (Q = S, Se) ligands
Zhang,Zheng,Wong,Wong,Leung
, p. 5255 - 5264 (2000)
Reactions of coordinatively unsaturated Ru[N(Ph2PQ)2]2(PPh3) (Q = S (1), Se (2)) with pyridine (py), SO2, and NH3 afford the corresponding 18e adducts Ru[N(Ph2PQ)2]2(PPh3)(L) (Q = S, L = NH3 (5); Q = Se, L = py (3), SO2 (4), NH3 (6)). The molecular structures of complexes 2 and 6 are determined. The geometry around Ru in 2 is pseudo square pyramidal with PPh3 occupying the apical position, while that in 6 is pseudooctahedral with PPh3 and NH3 mutually cis. The Ru-P distances in 2 and 6 are 2.2025(11) and 2.2778(11) ?, respectively. The Ru-N bond length in 6 is 2.185(3) ?. Treatment of 1 or 2 with substituted hydrazines L or NH2OH yields the respective adducts Ru[N(Ph2PQ)2]2(PPh3)(L) (Q = S, L = NH2NH2 (12), t-BuNHNH2 (14), 1-aminopiperidine (C5H10NNH2) (15); Q = Se, L = PhCONHNH2 (7), PhNHNH2 (8), NH2OH (9), t-BuNHNH2 (10), C5H10NNH2 (11), NH2NH2 (13)), which are isolated as mixtures of their trans and cis isomers. The structures of cis-14 and cis-15 are characterized by X-ray crystallography. In both molecular structures, the ruthenium adopts a pseudooctahedral arrangement with PPh3 and hydrazine mutually cis. The Ru-N bond lengths in cis-14·CH2Cl2 and cis-15 are 2.152(3) and 2.101(3) ?, respectively. The Ru-N-N bond angles in cis-14·CH2Cl2 and cis-15 are 120.5(4) and 129.0(2)°, respectively. Treatment of 1 with hydrazine monohydrate leads to the isolation of yellow 5 and red trans-Ru[N(Ph2PS)2]2(NH3)(H2O) (16), which are characterized by mass spectrometry, 1H NMR spectroscopy, and elemental analyses. The geometry around ruthenium in 16 is pseudooctahedral with the NH3 and H2O ligands mutually trans. The Ru-O and Ru-N bond distances are 2.118(4) and 2.142(6) ?, respectively. Oxidation reactions of the above ruthenium hydrazine complexes are also studied.
Thiosemicarbazonates of ruthenium(II): Crystal structures of [bis(diphenylphosphino)butane][bis(pyridine-2-carbaldehydethiosemicarbazonato)] ruthenium(II) and [bis(triphenylphosphine)][bis(benzaldehydethiosemicarbazonato)] ruthenium(II)
Lobana, Tarlok S.,Bawa, Gagandeep,Butcher, Ray J.,Liaw, Ben-Jie,Liu, Chen W.
, p. 2897 - 2903 (2006)
The reaction of Ru2Cl4(dppb)3 {dppb = Ph2P-(CH2)4-PPh2} with pyridine-2-carbaldehyde thiosemicarbazone {C5H4N{single bond}C(H){double bond, long}N3{single bond}N2H{single bond}C({double bond, long}S)NH2, Hpytsc}, and that of RuCl2(PPh3)3 with benzaldehyde thiosemicarbazone {C6H5{single bond}C(H){double bond, long}N3{single bond}N2H{single bond}C({double bond, long}S){single bond}NH2, Hbtsc}, in the presence of Et3N base led to loss of the -N2H- proton in each case, and yielded [Ru(pytsc)2(dppb)] (1) and [Ru(btsc)2(Ph3P)2] (2), respectively. The complexes are characterized with the help of analytical data, IR, NMR (1H, 13C, 31P) and single crystal X-ray study. In both compounds 1 and 2, the thiosemicarbazone ligands coordinate to Ru(II) via the hydrazinic nitrogen (N2) and sulfur atoms forming four membered rings, and the pyridyl group is pendant in 1. The geometry is distorted octahedral with cis:cis:trans P, P:N, N:S, S dispositions of donor atoms. Proton NMR confirmed loss of the -N2H- proton in both compounds, and the 31P NMR spectra reveal the presence of equivalent phosphorus atoms in both the compounds. Compound 1 represents the first example of a Ru(II)-thiosemicarbazone complex with a chelating diphosphine and it reveals the stability of a seven membered P,P-chelate ring in the presence of a potentially tridentate pytsc- ligand.
Dynamic Kinetic Resolution of Alcohols by Enantioselective Silylation Enabled by Two Orthogonal Transition-Metal Catalysts
Oestreich, Martin,Seliger, Jan
supporting information, p. 247 - 251 (2020/10/29)
A nonenzymatic dynamic kinetic resolution of acyclic and cyclic benzylic alcohols is reported. The approach merges rapid transition-metal-catalyzed alcohol racemization and enantioselective Cu-H-catalyzed dehydrogenative Si-O coupling of alcohols and hydrosilanes. The catalytic processes are orthogonal, and the racemization catalyst does not promote any background reactions such as the racemization of the silyl ether and its unselective formation. Often-used ruthenium half-sandwich complexes are not suitable but a bifunctional ruthenium pincer complex perfectly fulfills this purpose. By this, enantioselective silylation of racemic alcohol mixtures is achieved in high yields and with good levels of enantioselection.
Pyridine-pyridine-imidazoline-containing asymmetric NNN' pincerlike ruthenium compound and preparation method thereof
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Paragraph 0017, (2019/07/16)
The invention discloses a pyridine-pyridine-imidazoline-containing asymmetric NNN' pincerlike ruthenium compound and a preparation method thereof. A general formula of the pyridine-pyridine-imidazoline-containing asymmetric NNN' pincerlike ruthenium compound is shown in the description, wherein R1 is C1-C15 alkyl and aryl, and R2 is aryl. A synthesis method of the pincerlike ruthenium compound comprises the following steps: 2,2-bipyridyl is oxidized by hydrogen peroxide, nitrileated, and hydrolyzed to obtain 2,2-bipyridyl-6-carboxylic acid, the 2,2-bipyridyl-6-carboxylic acid is chlorinated, aminated, re-chlorinated and cyclized to obtain a ligand, and the ligand and RuCl2(PPh3)3 are refluxed in toluene to obtain the pyridine-pyridine-imidazoline-containing asymmetric NNN' pincerlike ruthenium compound. The invention provides a simple and convenient method for synthesizing the asymmetric pincerlike ruthenium compound by using inexpensive and readily available 2,2-bipyridyl as a starting material.
Ru(II)/N-N/PPh3 complexes as potential anticancer agents against MDA-MB-231 cancer cells (N-N?=?diimine or diamine)
Ribeiro, Gabriel H.,Colina-Vegas, Legna,Clavijo, Juan C.T.,Ellena, Javier,Cominetti, Marcia R.,Batista, Alzir A.
, p. 70 - 83 (2019/01/26)
The rational design of anticancer agents that acts in specific biological targets is one of the most effective strategies for developing chemotherapeutic agents. Aiming at obtaining new ruthenium (II) compounds with good cytotoxicity against tumor cells, a series of new complexes of general formula [RuCl(PPh3)(Hdpa)(N–N)]Cl [PPh3 = triphenylphosphine, N-N = 2,2′-dipyridylamine (Hdpa) (1), 1,2-diaminoethane (en) (2), 2,2′-bipyridine (bipy) (3), 5,5′-dimethyl-2,2′-bipyridine (dmbipy) (4), 1,10-phenanthroline (phen) (5) and 4,7-diphenyl-1,10-phenanthroline (dphphen) (6)] were synthesized. The complexes were characterized by elemental analysis and spectroscopic techniques (IR, UV/Visible, and 1D and 2D NMR) and three of their X-ray structures were determined: [RuCl(PPh3)(Hdpa)2]Cl, [RuCl(PPh3)(Hdpa)(en)]Cl and [RuCl(PPh3)(Hdpa)(dmbipy)]Cl. All the complexes are more cytotoxic against the cancer cell line than against the non-tumor cell line, highlighting complexes 1 and 5, which have an index selectivity of 18 and 15, respectively. The binding constants of compounds 1–6 with human serum albumin (HSA) were determined by tryptophan fluorescence quenching, indicating moderate to strong interactions. The binding mode of the complexes to calf thymus (CT) DNA was explored by several techniques, which reveal that only the dphphen compound 6 causes distortions in the secondary and tertiary structures of DNA. The studies demonstrated that the nature of the N–N co-ligand and the presence of the PPh3 and Hdpa ligands are features that can influence the binding affinity of the complexes by the biomolecules and in the cytotoxic activity of the complexes. Overall, the complexes with diimine co-ligand are much more cytotoxic than compound 2 with the aliphatic diamine.
Heteroleptic tris-chelate ruthenium(II) complexes of N,N-disubstituted-N′-acylthioureas: Synthesis, structural studies, cytotoxic activity and confocal microscopy studies
Barolli, Jo?o P.,Maia, Pedro I.S.,Colina-Vegas, Legna,Moreira, Jane,Plutin, Ana M.,Mocelo, Raúl,Deflon, Victor M.,Cominetti, Marcia R.,Camargo-Mathias, Maria I.,Batista, Alzir A.
, p. 33 - 41 (2017/02/13)
Ruthenium complexes have been assessed as anti-tumor agents against cancer cells. In this project, new heteroleptic ruthenium(II) complexes with general formulae [Ru(L)(bipy)(dppb)](PF6) (where L?=?N,N-disubstituted-N′-acylthiourea, bipy?=?2,2′-bipyridine and dppb?=?1,4-bis(diphenylphosphino)butane) were synthesized and characterized by elemental analysis, IR and NMR (1H and31P{1H}) spectroscopies, molar conductivity measurements and single crystal X-ray diffractometry. The IR and NMR data suggest the coordination of the ligands to the Ru(II) metal center through the thiocarbonyl and carbonyl groups. The structures of the new complexes were further studied by X-ray crystallography, which confirmed the coordination of the ligands with the metal through the sulfur and oxygen atoms, leading to the formation of distorted octahedral complexes. The N,N-disubstituted-N′-acylthioureas and their complexes were screened with respect to their in vitro cytotoxicity. All compounds exhibited considerable antiproliferative activity against MCF-7 (human breast tumor cells ATCC HTB-26), DU-145 (human prostate tumor cells ATCC HTB-26), and relatively low toxicity against fibroblast L929 cells (health cell line from mouse ATCC CCL-1). A preliminary study regarding the mechanism of action of these compounds by confocal microscopy shows alterations of the actin filaments leading to modifications in cytoskeletal supporting the cell death and that the cell nucleus is not main target of these complexes.
