Synthesis of Ruthenium Catalysts with a Chiral Arene Ligand Derived from Natural Camphor
Synthesis. 2022. Vol. 54. No. 21. P. 4721-4726.
Pototskiy R., Mikhail A. Boym, Nelyubina Y., Dmitry S. Perekalin
Ruthenium complex with chiral arene ligand [(camphor-arene)RuCl2]2 was synthesized by the reaction of RuCl3∙nH2O with the chiral diene, which was obtained from natural camphor in 3 steps. This complex catalyzed asymmetric hydrogenation of acetophenone (64-85% ee), but decomposed in the catalytic reactions involving C-H activation of 2-phenyl-pyridine or benzoic acid derivatives.
Research target: Chemistry
Enhancing the efficiency of the ruthenium catalysts in the reductive amination without an external hydrogen source
, , et al., Journal of Catalysis 2022 Vol. 405 P. 404-409
Catalytic reductive reactions are essential for laboratory and industrial-scale organic synthesis. However, the nowadays trend is the development of new, progressively more complicated reducing systems, which hinders the application of such highly efficient approaches in practice. Another way to achieve highly active systems is enhancing the activity of the earlier developed catalysts with simple structures. ...
Added: January 11, 2022
Asymmetric cyclopropanation of electron-rich alkenes by the racemic diene rhodium catalyst: the chiral poisoning approach
, , et al., Chemical Communications 2022 Vol. 58 No. 47 P. 6709-6712
Asymmetric cyclopropanation of alkenes by aryldiazoacetates was achieved using the readily-available racemic (diene)rhodium complex in combination with the chiral oxazoline-phenol ligand, which acts as the chiral poison and selectively inhibits one of the enantiomers of the catalyst. This approach eliminates a common problematic step of the synthesis of the chiral catalysts. ...
Added: January 24, 2023
Synthesis of Rhodium Complexes with Chiral Diene Ligands via Diastereoselective Coordination and Their Application in the Asymmetric Insertion of Diazo Compounds into E−H Bonds
, , et al., Angewandte Chemie - International Edition 2021 Vol. 60 No. 34 P. 18712-18720
A new method for the synthesis of chiral diene rhodium catalysts is introduced. The readily available racemic tetrafluoro-benzobarrelene complexes [(R 2 -TFB)RhCl] 2 were separated into two enantiomers via selective coordination of one of them with the auxiliary S -salicyl-oxazoline ligand. One of the resulting chiral complexes with an exceptionally bulky diene ligand [( R,R ...
Added: January 24, 2023
, , et al., Mendeleev Communications 2017 Vol. 27 No. 6 P. 615-617
The hydrogenation of diphenylacetylene (DPA) on palladium–silver catalysts with a single-atom structure was investigated. It has been shown experimentally that the reaction rate of alkene to alkane hydrogenation is substantially lower than the rate of DPA semi-hydrogenation. The kinetic barriers of all stages of hydrogenation were calculated by the DFT method. ...
Added: October 26, 2018
Accessing Mononuclear Triphenylcyclopentadienyl Lanthanide Complexes by Using Tridentate Nitrogen Ligands: Synthesis, Structure, Luminescence, and Catalysis
, , et al., Organometallics 2021 Vol. 40 No. 9 P. 1235-1243
A series of mononuclear aryl-substituted cyclopentadienyl complexes [CpPh3LnCl2(Me3tach)] (Ln = Tb (4), Ln = Nd (5)), [CpPh2ArTbCl2(Me3tach)] (6), and [CpPh3LnCl2(Me3tacn)] (Ln = Tb (7), Ln = Nd (8), CpPh3: 1,2,4-triphenylcyclopentadienyl, CpPh2Ar: 1,2-diphenyl-4-(o-methoxyphenyl)cyclopentadienyl, Me3tach: 1,3,5-trimethyl-1,3,5-triazacyclohexane, Me3tacn: 1,4,7-trimethyl-1,4,7-triazacyclononane) have been synthesized from polynuclear precursors, using cyclic tridentate nitrogen-based ligands to prevent formation of ate complexes. All the obtained complexes have been ...
Added: June 26, 2021
Cyclobutadiene platinum complex as a new type of precatalyst for hydrosilylation of alkenes and alkynes
, , , Applied Organometallic Chemistry 2023 Vol. 37 No. 3 Article e7008
The readily available cyclobutadiene platinum complex [(C4Et4)PtCl2] catalyzes hydrosilylation of alkenes and alkynes. The reaction typically proceeds at room temperature and does not require any solvent. The target products are obtained from both terminal and internal alkynes, as well as from terminal alkenes in 43−99% yields. The scope of silanes includes various tertiary silanes (Et3SiH, ...
Added: January 24, 2023
, , , Organometallics 2022 Vol. 41 No. 21 P. 3038-3043
The parent ethylene rhodium(I) complex [(C2H4)2RhCl]2 reacts with internal alkynes to give binuclear metallacycles [(C4R4)Rh2Cl2(C2H4)]2 (R = Me, Et, CH2OMe, Ph), which can act as catalytic intermediates in cyclotrimerization reactions. These metallacycles can be converted into catalytically inert metallocenes CpRh(η5-C4R4RhCp) by addition of CpTl. Further reactions of these metallocenes with [CpRhI2]x and AgBF4 lead to ...
Added: January 24, 2023
, , , Carbon 2021 Vol. 175 P. 202-214
Based on the quantum-mechanical theory of electron transfer (ET), the parameter was proposed to describe the electrochemical activity of doped graphenes. The parameter is calculated using the density of states (DOS), local density of state (LDOS) values, which are in turn obtained from the density functional theory (DFT) calculations and reorganization energies of redox system. ...
Added: January 12, 2021
Synthesis of Overloaded Cyclopentadienyl Rhodium(III) Complexes via Cyclotetramerization of tert-Butylacetylene
, , et al., Organometallics 2021 Vol. 40 No. 22 P. 3712-3719
Herein we describe the synthesis and reactivity of rhodium catalysts with the very bulky cyclopentadienyl ligand C8H3tBu4 (designated as tBu4Cp). The reaction of [Rh(cod)Cl]2 with tert-butylacetylene in the presence of Et3N gives the complex (tBu4Cp)Rh(cod) (60–65% yield), in which the cyclopentadienyl ligand tBu4Cp is assembled from four alkyne molecules. The oxidation of (tBu4Cp)Rh(cod) with chlorine or bromine gives the corresponding ...
Added: January 24, 2023
, , et al., Радиохимия 2016 Т. 58 № 6 С. 506-511
The electrochemical properties of URu3 intermetallic compound (IMC) in 0.5–8 M HNO3 solutions were studied by linear voltammetry and galvanostatic electrolysis. In 0.5–2 M HNO3, URu3 occurs in the passive state at potentials lower than +1.3 V (here and hereinafter, vs. SHE), and in 4–8 M HNO3, an anodic oxidation peak is observed at potentials ...
Added: September 26, 2019
Циклометаллированный комплекс рутения с 3,3',5,5'-тетраметил-1,1'-бифенил-4,4'-бипиразолом и 2,2'-дикарбоксибипиридином: синтез, оптические свойства и квантово-химическое моделирование
, , et al., Координационная химия 2022 Т. 48 № 6 С. 343-351
Новый комплекс [RuL(Dmdcbp)2]PF6 (I) получен последовательным взаимодействием [Ru-p-cymene]2Cl4 с 3,3',5,5'-тетраметил-1,1'-бифенил-4,4'-бипиразолом (L) и 4,4'-дикарбокси-2,2'-бипиридином в среде метанол–хлороформ. Состав комплекса I подтвержден методами ЯМР и элементным анализом, изучены оптические и люминесцентные свойства комплекса. Лиганд L впервые охарактеризован методом РСА (CIF file CCDC № 2118676). Для интерпретации спектров поглощения и испускания проведены квантово-химические расчеты в рамках теории функционала плотности. Комплекс ...
Added: October 17, 2022
Cyclobutadiene Rhodium Complexes as Catalysts for the Synthesis of Amides from Electron-rich Arenes, Tosyl Azide and CO
, , , ChemCatChem 2021 Vol. 13 No. 12 P. 2873-2878
Cyclobutadiene rhodium complexes [(C4R4)RhX]2 (R=Et, Ph; X = I, Cl) at 0.5 mol% loading catalyze the formation of aromatic amides from various indoles, tosyl azide, and carbon monoxide (1 atm). The reaction gives good yields of the target products (typically 60‐85%) and tolerates both donor and moderately acceptor substituents in the indoles (alkyl, OMe, Hal, ...
Added: January 24, 2023
, , et al., European Journal of Organic Chemistry 2018 Vol. 2018 No. 4 P. 557-563
A catalytic system for the atom‐economical Ru‐catalyzed reductive amidation of aldehydes was developed. A cyclopentadienyl ruthenium catalyst was employed in this process with loadings as low as 0.5–1 mol‐%, and carbon monoxide was used as the deoxygenative agent. A number amides and aromatic aldehydes were able to successfully afford the corresponding secondary amide in yields ...
Added: June 26, 2019
Henry Reaction Revisited. Crucial Role of Water in an Asymmetric Henry Reaction Catalyzed by Chiral NNO-Type Copper(II) Complexes
, , et al., Inorganic Chemistry 2019 Vol. 58 No. 16 P. 11051-11065
Chiral copper(II) and cobalt(III) complexes (1–5 and 6, respectively) derived from Schiff bases of (S)-2-(aminomethyl)pyrrolidine and salicylaldehyde derivatives were employed in a mechanistic study of the Henry reaction-type condensation of nitromethane and o-nitrobenzaldehyde in CH2Cl2 (CD2Cl2), containing different amounts of water. The reaction kinetics was monitored by 1H and 13C NMR. The addition of water ...
Added: October 10, 2019
Synthesis, structure and electrochemical properties of 1-ferrocenyl-3-cymantrenyl-containing beta-diketone, pyrazole and mixed-metal chelated complex of p-cymene-ruthenium-iodide
, Polyhedron 2018 Vol. 149 P. 73-78
Claisen condensation of acetylferrocene (eta(5)-C5H5)Fe(eta(5)-C5H4COCH3) and methyl ether of cymantrenecarboxylic acid (CO)(3)Mn(eta(5)-C5H(4)COOMe) results in beta-diketone (eta(5)-C5H5)Fe(eta(5)-C5H4)-C(O) CH2C(O)-(eta(5)-C5H4)Mn(CO)(3) (I) which reacts with hydrazine to form a heterometallic pyrazole (eta(5)-C5H5)Fe(eta(5)-C5H4)-N2C3H3-(eta(5)-C5H4)Mn(CO)(3) (II) or reacts with diiodo(p-cymene)ruthenium(II) dimer giving chelate beta-ketoenolate complexes of ruthenium, (p-cymene)RuI[eta(5)-C5H5)Fe(eta(5)-C5H4)-C(O)CHC(O)-(eta(5)-C5H4)Mn(CO)(3)] (III). The structures of complexes I-III were determined by single crystal X-ray diffraction. Electrochemical ...
Added: December 2, 2019
, , et al., Chemical Communications 2021 Vol. 57 No. 91 P. 12167-12170
A new protocol is developed for the mono- and bis-ortho-C–H alkynylation of easily accessible benzamide derivatives using alkynyl bromides at room temperature by merging cobalt and photocatalysts. The diverse reactivity of various alkynyl bromides towards the C–H alkynylation and competing C–H/N–H bond annulation reactions has been demonstrated to give the corresponding products in good yields ...
Added: January 24, 2023
, , et al., Materials Research Bulletin 2022 Vol. 155 Article 111971
The phase composition, microstructure, electrical and thermal conductivity of Nd2±xHf2±xO7±δ ceramic materials have been studied. (Nd2-xHfx)Hf2O7+x/2 (x = 0.2, 0.32, 0.39) composites, containing 4–16 wt% HfO2, have the highest conductivity and the brightest narrow-band luminescence among materials under study. The (Nd2-xHfx)Hf2O7+x/2 (x = 0.2) composite, containing ~ 4 wt % HfO2, is shown to have ...
Added: July 16, 2022
Effect of different organic additives on the shape, size and scintillation properties of Bi4Ge3O12 powders synthesized by the microwave-hydrothermal method
, , et al., Advanced Powder Technology 2021 Vol. 32 No. 1 P. 175-185
A route for production of fine Bi4Ge3O12 (BGO) powder is sought after to lower the cost of scintillation devices and make their shapes more versatile. A systematic study of highly dispersed BGO crystallization under the hydrothermal-microwave (HTMW) conditions was carried out in the present work. Anionic, cationic and non-ionic surfactants, chelating agents and polyols were used to modify ...
Added: October 23, 2022
Reply to Comment on ‘Nonlocal statistical field theory of dipolar particles in electrolyte solutions’
, Journal of Physics: Condensed Matter 2019 Vol. 31 P. 078002-078003
We reply to the comment on our paper by Budkov (2018 J. Phys.: Condens. Matter 30 344001). ...
Added: January 4, 2019
Effects of Support Structure and Composition on the Activity of Cu–Ni Catalysts for Methanol Steam Reforming
, , et al., Inorganic Materials 2019 Vol. 55 No. 12 P. 1230-1236
We have studied the catalytic activity of Cu–Ni bimetallic catalysts on yttrium-, tin-, zinc-, and niobium-doped zirconia and ceria supports for methanol steam reforming (MSR), a process for hydrogen production, and examined the effect of the nature of the dopants and annealing temperature on the structure and particle size of the oxide supports and the ...
Added: November 18, 2019
Synthesis, molecular structure and catalytic performance of heterocycle-fused cyclopentadienyl-amido CGC of Ti (IV) in ethylene (co)polymerization: The formation and precision rheometry of long-chain branched polyethylenes
, , et al., European Polymer Journal 2022 Vol. 176 Article 111397
Long-chain branching is an efficient tool to design and produce polyolefins with enhanced mechanical characteristics, physical properties, and processability. In the synthesis of long-chain branched polyethylene (LCB PE), constrained geometry complexes (CGCs) of Ti (IV) [(η5-C5Me4)SiMe2NtBu]TiX2 (X = Cl, Ti1; X = alkyl) are highly effective at elevated temperatures. However, further development of polyolefin technologies ...
Added: September 12, 2022
, , , Журнал прикладной химии 2021 Т. 94 № 3 С. 275-295
Materials-science aspects of the development of color road pavement (color asphalt concretes) and marking are considered. Kinds of binders used as a base for color asphalt concretes are characterized; these include dark petroleum bitumens, colorless polymer binders, and biobinders. The main requirements to colorless binders are formulated. The relationship between the composition and physicochemical, mechanical, ...
Added: January 29, 2023
Evaluation of the Possibility to Use Coalbed Methane to Produce Methanol Both by Direct Partial Oxidation and From Synthesis Gas
, , et al., Eurasian Chemico-Technological Journal 2022 Vol. 24 No. 2 P. 157-163
The possibility of using coalbed methane to produce methanol is assessed. Methanol can be obtained from methane both by direct partial oxidation and from synthesis gas formed through the oxidative conversion of methane. Thermodynamic analysis of coalbed methane conversion was carried out to determine the conditions for obtaining synthesis gas with the ratio [H2 ]/[CO] = ...
Added: October 7, 2022
, , et al., Batteries 2022 Vol. 8 No. 8 Article 98
Nanostructure composites Ge-Co-P with brutto-composition CoGe2P0.1, or CoGe2@GeP were manufactured via electrolysis of aqueous electrolyte. Such composites are able to reversible insertion of lithium and sodium with specific capacities up to 855 and 425 mAh/g, respectively. The main advantage of the composites consists in their excellent cycleability. ...
Added: November 25, 2022