A5089785638- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Crystallography and molecular interactions
- N-Heterocyclic Carbenes in Organic and Inorganic Chemistry
- Metal complexes synthesis and properties
- Catalytic C–H Functionalization Methods
- Oxidative Organic Chemistry Reactions
- Asymmetric Synthesis and Catalysis
- Boron Compounds in Chemistry
- Synthesis and Biological Evaluation
- Chemical Reaction Mechanisms
- Vanadium and Halogenation Chemistry
- Structural and Chemical Analysis of Organic and Inorganic Compounds
- Catalytic Cross-Coupling Reactions
- Organic Chemistry Cycloaddition Reactions
- Organoboron and organosilicon chemistry
- Synthesis and Catalytic Reactions
- Metal-Organic Frameworks: Synthesis and Applications
- Synthesis and Characterization of Heterocyclic Compounds
- Radioactive element chemistry and processing
- Asymmetric Hydrogenation and Catalysis
- Crystal structures of chemical compounds
- Organometallic Complex Synthesis and Catalysis
- Pharmacological Effects and Toxicity Studies
- Synthesis and biological activity
St Petersburg University
2016-2025
Dibenziodolium and diphenyliodonium triflates display high catalytic activity for the multicomponent reaction that leads to a series of imidazopyridines. Density functional theory (DFT) calculations indicate both salts can play role hybrid hydrogen- halogen-bond-donating organocatalysts, which electrophilically activate carbonyl imine groups during process. The ortho-H atoms in vicinal position I atom dual role: forming additional noncovalent bonds with ligated substrate increasing maximum...
Sulfonium and selenonium salts, represented by S-aryl dibenzothiophenium Se-aryl dibenzoselenophenium triflates, were found to exhibit remarkable catalytic activity in the model Groebke–Blackburn–Bienaymé reaction. Kinetic analysis density functional theory (DFT) calculations indicated that their effect is induced ligation of reaction substrates σ-holes on S or Se atom cations. The experimental data although 10-fold excess chloride totally inhibits sulfonium salt remains catalytically...
The complexes [MII(acac)2] (M = Cu 1, Pd 2, Pt 3; Hacac acetylacetone) and 1,4-diiodotetrafluorobenzene (FIB) were cocrystallized in CHCl3–MeOH solutions to form adducts (1–3)·FIB, whose structures studied by X-ray diffraction. association leads unification of the three structures, thus demonstrating potential isostructural Cu/Pd/Pt exchange for construction supramolecular systems involving complexes. In crystal intermolecular bifurcated halogen bonding I···μ2-(O,O) noncovalent interactions...
The dibenziodolium cation displays high catalytic activity for the Knorr-type reactions <italic>via</italic> binding with carbonyl O atom.
Solvation effects might play the dominant role in catalysis providing an increase or suppression of activity organocatalysts.
Sulfonium, selenonium, telluronium, and iodonium cyanoborohydrides have been synthesized, isolated, fully characterized by various methods, including single-crystal X-ray diffraction (XRD) analysis. The quantum theory of atoms in molecules' analysis based on the XRD data indicated that hydride···σ-hole short contacts observed crystal structures each compound a purely noncovalent nature. telluronium provide significantly higher rate model reaction imine hydrogenation compared with sodium...
Three types of oxime species, i.e., 4-morpholylcarbamidoxime (hydroxyguanidine), phenylacetamidoxime and benzamidoxime (amidoximes), cyclohexanone benzophenone (ketoximes), react at room temperature with the 2-nitrilium closo-decaborate clusters, leading to 2-iminium closo-decaborates (14 examples; 57–94%). These species were characterized by ICPMS-based boron elemental analysis, HRESI–-MS, molar conductivity, IR, 1H{11B}, 11B{1H} NMR spectroscopies, additionally single-crystal X-ray...
Three types of N(H)-nucleophiles were used to study the nucleophilic addition CN group 2-propanenitrilium<italic>closo</italic>-decaborate cluster giving<italic>N-closo</italic>-decaborato amidrazones.
This report demonstrates the successful application of electrostatic surface potential distribution analysis for evaluating relative catalytic activity a series azolium-based halogen bond donors. A strong correlation (R2 > 0.97) was observed between positive σ-hole on atom and Gibbs free energy activation model reactions (i.e., abstraction carbonyl activation). The predictive ability applied approach confirmed experimentally. It also determined that donors generally governed by structure...
This theoretical study sheds light on the relative catalytic activity of pnictonium, chalconium, and halonium salts in reactions involving elimination chloride electrophilic activation a carbonyl group. DFT calculations indicate that for cationic aromatic onium salts, values electrostatic potential heteroatom σ-holes gradually increase from pnictogen- to halogen-containing species. The higher halogen atoms result overall these species, but case pnictonium chalconium cations, weak...
Kinetic data based on 1 H NMR monitoring and computational studies indicate that in solution, pyrazole-containing iodonium triflates silver(I) triflate bind to each other, such an interplay results the decrease of total catalytic activity mixture these Lewis acids compared separate catalysis Schiff condensation, imine-isocyanide coupling, or nucleophilic attack a triple carbon-carbon bond. Moreover, kinetic cooperation with prevention decomposition salts during reaction progress. XRD study...
Abstract The experimentally obtained kinetic data has indicated the existence of a synergetic cocatalytic effect provided by an iodonium salt in base‐catalyzed Knoevenagel condensation. diphenyliodonium triflate serving as halogen bond‐donating Lewis acid provides higher than zinc(II) or triflic serving, respectively, metal cation‐based and Brønsted acid. Such remains same for broad scope carbonyl compounds covering aldehydes featuring electron‐withdrawing electron‐donating substituents,...
Abstract Sulfonium, selenonium, telluronium triflates, as well chloronium, bromonium, and iodonium triflates have been examined in the model Schiff condensation chalcogen‐ halogen bond donating organocatalysts, respectively. The kinetic data indicated that catalytic effect of salt is provided via decrease enthalpy activation reaction, whereas – unexpectedly caused by value entropy activation. In addition, it was experimentally shown activity sulfonium selenonium salts significantly lower...
Chalconium and halonium salts catalyze Schiff condensation. Kinetic data DFT calculations show that the catalytic activity correlates with maximum electrostatic potential on σ-holes, whereas other factors are less significant.
The cyanamides Me2NCN (1a), OC4H8NCN (1b), and PhC(═O)N(H)CN (1c) the conventional nitriles PhCN (1d) EtCN (1e) react with 1 equiv of each amidoximes R'C(═NOH)NH2 (R' = Me (2a), Ph (2b)) in presence ZnCl2 producing complexes [ZnCl2{HN═C(R)ON═C(R')NH2}] (R/R' NMe2/Me (3a), NMe2/Ph (3b), NC4H8O/Me (3c), NC4H8O/Ph (3d), N(H)C(═O)Ph/Me (3e), N(H)C(═O)Ph/Ph (3f), Ph/Me (3g), Ph/Ph (3h), Et/Ph (3j)) chelate ligands originating from previously unreported zinc(II)-mediated nitrile-amidoxime...
A suitable model for computational study giving reliable estimation of the catalytic effect σ-hole donating organocatalysts is suggested.
Amidoximes react with zinc salts in undried EtOAc furnishing the trinuclear species, where amidoximes are stabilized aminonitrone form.
Computations indicate that cationic and noncharged xenon derivatives should exhibit higher catalytic activity than their iodine-based noncovalent organocatalytic congeners. Perfluorophenyl xenonium(II) is expected to demonstrate the best balance between chemical stability for use in organocatalysis. Comparing its with of isoelectronic perfluoroiodobenzene indicates high organocatalysts predominantly attributed electrostatic interactions reaction substrates, which cause polarization ligated...
The nucleophilic addition of amidoximes R′C(NH2)═NOH [R′ = Me (2.Me), Ph (2.Ph)] to coordinated nitriles in the platinum(II) complexes trans-[PtCl2(RCN)2] [R Et (1t.Et), (1t.Ph), NMe2 (1t.NMe2)] and cis-[PtCl2(RCN)2] (1c.Et), (1c.Ph), (1c.NMe2)] proceeds a 1:1 molar ratio leads monoaddition products trans-[PtCl(RCN){HN═C(R)ONC(R′)NH2}]Cl NMe2; R′ ([3a]Cl), ([3b]Cl)], cis-[PtCl2{HN═C(R)ONC(R′)NH2}] (4a), (4b)], trans/cis-[PtCl2(RCN){HN═C(R)ONC(R′)NH2}] Et; (5a, 6a), (5b, 6b); R Ph; (5c, 6c),...
Abstract The nucleophilic addition of amidoximes R′C(NH 2 )NOH ( 4 : R′=Me, 5 CH Ph, 6 Ph) to coordinated nitriles in the platinum(IV) complexes trans ‐[PtCl (RCN) ] 1 R=Et, 3 NMe ) proceeds a 1:1 molar ratio and leads monoaddition products [PtCl (RCN){H N C(R)ONC(R′)NH }] 7 R/R′: Et/CH 8 Et/Ph, 9 /CH 10 /Ph). Meanwhile, if 2:1 reaction gives bisaddition species {H } 11 R/R′=Et/Me, 12 13 14 Ph/Ph, 15 /Me, 16 17 All – bear nitrogen‐bound O‐iminoacylated amidoxime groups. one equivalent...
An acyclic diphenyliodonium cation forms stronger interactions with a bulky Lewis base than cyclic dibenziodolium cation.