157072-60-1Relevant articles and documents
Urinary tract infection fighting potential of Newly synthesized ruthenium carbonyl complex of N-dehydroacetic acid-N′-o-vanillin-ethylenediamine
Mir,Jain,Malik,Chourasia,Vishwakarma,Rajak,Maurya
, p. 80 - 92 (2017)
In recent years, there has been a growing fascination towards the development of new antimicrobial agents from various sources to combat microbial resistance. Klebsiella pneumonia and E. coli are the main urinary tract infection (UTI) causing agents. Herein, we report the synthesis and characterization of a novel carbonyl complex of Ru(II) that has been found a good antimicrobial agent against the selected microbes. Hence, may be suggested as potent agent against UTI. The compound on characterization was found octahedral in structure on the basis of comparative DFT-experimental characterization. Molecular specification under B3LYP functional, LANL2DZ basis set for Ru atom and 6-31?g(d,p) for all other atoms were employed. Electron density plots and geometrical optimization were the main theoretical aspects that were invoked. Elemental analysis, mass spectrometry, NMR, FT-IR, UV–Vis and cyclic voltammetry were the physio-chemical techniques at both the experimental and theoretical fronts that helped to establish the proposed structure. From the overall study, it may be remarked that both observed and computed outcomes have been found in good agreement with each other.
Detection and Structural Investigation of Elusive Palladium Hydride Intermediates Formed from Simple Metal Salts
Kostyukovich, Alexander Yu.,Burykina, Julia V.,Eremin, Dmitry B.,Ananikov, Valentine P.
, p. 7128 - 7142 (2021)
The Mizoroki-Heck reaction is one of the most known and best studied catalytic transformations and has provided an outstanding driving force for the development of catalysis and synthetic applications. Three out of four classical Mizoroki-Heck catalytic cycle intermediates contain Pd-C bonds and are well known and studied in detail. However, a simple palladium hydride (which is formed after the product-releasing β-H-elimination step) is a kind of elusive intermediate in the Mizoroki-Heck reaction. In the present study, we performed a combined theoretical and mass spectrometry (MS) study of palladium hydride complexes [PdX2H]- (X = Cl, Br, and I), which are reactive intermediates in the Mizoroki-Heck reaction. Static and molecular dynamic calculations revealed that these species have a T-shaped structure with a trans-arrangement of halogen atoms. Other isomers of [PdX2H]- are unstable and easily rearrange into the T-shaped form or decompose. These palladium hydride intermediates were detected by MS in precatalyst activation using NaBH4, Et3N, and a solvent molecule as reducing agents. Online MS monitoring allowed the detection of [PdX2H]- species in the course of the Mizoroki-Heck reaction.
Half-way coordination state of a butadienyl group on ruthenium. η3-Allylic bonding with η1-character or vice versa.
Wakatsuki, Yasuo,Yamazaki, Hiroshi,Maruyama, Yooichiroh
, p. C60 - C63 (1992)
The butadienyl complexes formed by the reaction of trans-(R1)CH=CHCCR2 (R1, R2=SiMe3, t-Bu, Me, Et) with RuCl(CO)H(PPh3)3 exhibit unique structures: instead of taking the 18-electron configuration of the metal by conventional η3-coordination of the butadienyl ligand, they shift significantly to the 16-electron η1-coordination state.
PREPARATION OF OCTAHEDRAL, HYDRIDO-AQUO-RUTHENIUM(II) COMPLEXES, AND STRUCTURAL CHARACTERISATION OF HYDRIDOAQUODICARBONYLBIS(TRIPHENYLPHOSPHINE)RUTHENIUM(II) TETRAFLUOROBORATE
Boniface, Suzanne M.,Clark, George R.,Collins, Terrence J.,Roper, Warren R.
, p. 109 - 117 (1981)
Reaction of RuH2(CO)(PPh3)3 with tetrafluoroboric acid/water gives BF4.Carbonylation of the latter compound yields BF.In the Ir spectra of these compounds, splitting of the asymmetric BF4- stretching band indicated the possibility of a coordinated tetrafluoroborato ligand, but an X-ray study of BF4 shows that the BF4- is not coordinated to the metal, but is involved in a network of hydrogen bonds with the coordinated water molecule and the ethanol molecule of crystallisation.The crystal are monoclinic, space group P21 with Z = 2 in a unit cell of dimensions a = 9.3959(4), b = 22.695(1), c = 9.7878(3) Angstroem, β - 109.12(1) deg.The observed and calculated densities are 1.39 and 1.404 g cm-3 respectively.The structure was solved by conventional methods and refined using the full-matrix least-squares equations to final residuals R and Rw of 0.048 and 0.064 respectively.The ruthenium atom is in a distorted octahedral coordination geometry.The Ru-CO distances (1.83 and 1.97(2) Angstroem) differ significantly, with the longer bond situated trans to the hydrido ligand.The Ru-P bonds (2.329 and 2.416(5) Angstroem) are also significantly different, and the P-Ru-P angle is markedly non-linear at 165.1(2) deg.This asymmetry can be attributed to crystal packing forces.
Hydrogenation of olefins over hydrido chlorocarbonyl tris-(triphenylphosphine) ruthenium(II) complex immobilized on functionalized MCM-41 and SBA-15
Joseph, Trissa,Deshpande,Halligudi,Vinu,Ernst,Hartmann
, p. 13 - 21 (2003)
Hydrido chlorocarbonyl tris-(triphenylphosphine) ruthenium(II) complex [RuHCl(CO)(PPh3)3] has been immobilized inside the pores of amine functionalized MCM-41 and SBA-15 materials. These grafted complexes were characterized by XRD, F
Mechanistic study of ruthenium-catalyzed hydrosilation of 1- (Trimethylsilyl)-1-buten-3-yne
Maruyama, Yooichiroh,Yamamura, Kunihiro,Nakayama, Isao,Yoshiuchi, Keigo,Ozawa, Fumiyuki
, p. 1421 - 1429 (1998)
Catalytic hydrosilation of 1-(trimethylsilyl)-1-buten-3-yne (1) with three kinds of hydrosilanes (HSiMePh2, HSiMe2Ph, and HSiEt3) in CDCl3 at 30 °C in the presence of a catalytic amount of RuHCl(CO)(PPh3)3 (2) gave five types of reaction products: (1E,3E)-CH(SiR3)=CHCH=CHSiMe3 (3), R3SiCH2-CH=CHCH2SiMe3 (4), R3SiCH=C=CHCH2SiMe3 (5), (1Z,3E)- CH(SiR3)=CHCH=CHSiMe3 (6), and R3SiC≡CCH=CHSiMe3 (7). Detailed investigations on the stoichiometric reactions of intermediate ruthenium species provided definitive evidence for the catalytic mechanism comprised of two catalytic cycles, the Chalk-Harrod cycle A and the modified Chalk-Harrod cycle C, and their interconnecting processes B and D. Product 3 is formed by the insertion of 1 into the Ru-H bond of 2 followed by the reaction of the resulting terminal dienyl complex Ru(CH=CHCH=CHSiMe3)Cl(CO)(PPh3)2 (8) with hydrosilane. The latter process regenerates 2 and the sequence of reactions proceeds catalytically (cycle A). The reaction of 8 with hydrosilane is accompanied by a side reaction giving Ru(SiR3)Cl(CO)(PPh3)2 (9) and CH2=CHCH=CHSiMe3 (10), and the latter is further converted to 4 by hydrosilation (process B). Silyl complex 9 thus generated in the system is the key intermediate for catalytic cycle C. Thus the insertion of 1 into the Ru-SiR3 bond of 9 via a formal trans-addition process forms an internal dienylruthenium complex Ru[C(CHSiR3)CH=CHSiMe3]Cl(CO)-(PPh3)2 (11), which reacts with hydrosilane to give 5 and 6 and to regenerate 9. A part of 11 also undergoes β-hydrogen elimination to give a dehydrogenative silation product 8 and hydride complex 2. Complex 2 thus formed resumes catalytic cycle A (process D). The catalytic intermediates 8, 9, and 11 were identified by NMR spectroscopy and/or elemental analysis. Factors controlling the catalytic cycles are discussed on the basis of the experimental observations.
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.
Preparation and Reactivity of Mixed-Ligands Hydride Complexes [RuHCl(CO)(PPh3)2{P(OR)3}]
Albertin, Gabriele,Antoniutti, Stefano,Castro, Jesús
, p. 688 - 693 (2019/05/10)
Mixed-ligands hydride complexes [RuHCl(CO)(PPh3)2{P(OR)3}] (2) (R = Me, Et) were prepared by allowing [RuHCl(CO)(PPh3)3] (1) to react with an excess of phosphites P(OR)3 in refluxing benzene. Treatment of hydrides 2 first with triflic acid and next with an excess of hydrazine afforded hydrazine complexes [RuCl(CO)(κ1-NH2NHR1)(PPh3)2{P(OR)3}]BPh4 (3, 4) (R1 = H, CH3). Diethylcyanamide derivatives [RuCl(CO)(N≡CNEt2)(PPh3)2{P(OR)3}]BPh4 (5) were also prepared by reacting 2 first with HOTf and then with N≡CNEt2. The complexes were characterized spectroscopically and by X-ray crystal structure determination of [RuHCl(CO)(PPh3)2{P(OEt)3}] (2b).
Ionic Pd/NHC Catalytic System Enables Recoverable Homogeneous Catalysis: Mechanistic Study and Application in the Mizoroki–Heck Reaction
Eremin, Dmitry B.,Denisova, Ekaterina A.,Yu. Kostyukovich, Alexander,Martens, Jonathan,Berden, Giel,Oomens, Jos,Khrustalev, Victor N.,Chernyshev, Victor M.,Ananikov, Valentine P.
supporting information, (2019/11/14)
N-Heterocyclic carbene (NHC) ligands are ubiquitously utilized in catalysis. A common catalyst design model assumes strong M–NHC binding in this metal–ligand framework. In contrast to this common assumption, we demonstrate here that lability and controlled cleavage of the M?NHC bond (rather than its stabilization) could be more important for high-performance catalysis at low catalyst concentrations. The present study reveals a dynamic stabilization mechanism with labile metal–NHC binding and [PdX3]?[NHC-R]+ ion pair formation. Access to reactive anionic palladium intermediates formed by dissociation of the NHC ligands and plausible stabilization of the molecular catalyst in solution by interaction with the [NHC-R]+ azolium ion is of particular importance for an efficient and recyclable catalyst. These ionic Pd/NHC complexes allowed for the first time the recycling of the complex in a well-defined form with isolation at each cycle. Computational investigation of the reaction mechanism confirms a facile formation of NHC-free anionic Pd in polar media through either Ph–NHC coupling or reversible H–NHC coupling. The present study formulates novel ideas for M/NHC catalyst design.
Palladium-Catalyzed Direct Intramolecular C-N Bond Formation: Access to Multisubstituted Dihydropyrroles
Jiang, Bing,Meng, Fei-Fan,Liang, Qiu-Ju,Xu, Yun-He,Loh, Teck-Peng
supporting information, p. 914 - 917 (2017/02/26)
A palladium-catalyzed intramolecular amination of alkenes with retention of olefin functionalization was achieved under mild reaction conditions. In the presence of palladium catalyst, the tosyl-protected amine can directly couple with a double bond to provide versatile dihydropyrrole derivatives in moderate to excellent yields.
