Redox conversions of new antiviral drug Triazavirin®: electrochemical study and ESR spectroscopy

Russian Chemical Bulletin - The results of studying electrochemical conversions of 7-R-3-X-1,2,4-triazolo[5,1-c][1,2,4]-triazin-4-ones (Triazavirin® and its derivatives) using cyclic...     

Synthesis of Salts and Ionic Liquids on the Basis of 2-Aminothiazolium Cations

Russian Journal of General Chemistry - The base-free reactions of 2-aminothiazole with α-iodoketones were studied. Depending on the reaction conditions, linear or cyclic 2-aminothiazolium...     

Role of Water in the Photochemical Synthesis of Methyl 12-Oxo-6,12-dihydroazepino[2,1-b]quinazoline-8-carboxylates

Russian Journal of General Chemistry - Methyl 12-oxo-6,12-dihydroazepino[2,1-b]quinazoline-8-carboxylate and methyl 3H-azepin-2(1H)-one-5-carboxylate were synthesized by photoinduced...     

A New Metal-Organic Framework: Product of Solvothermal Synthesis in 3D-Printed Autoclaves

Russian Journal of Coordination Chemistry - A new metal-organic framework {Zn4(BDC)3(OAc)2(DMF)4} (BDC = terephthalate anion) was synthesized under solvothermal conditions in a 3D-printed...     

TBAI/TBHP-Catalyzed Synthesis of [1,2,4]Triazolo[4,3-a]pyridines and 3,5-Diaryl-1,2,4-oxadiazoles via Oxidative Cleavage of C=C Double Bond

Russian Journal of Organic Chemistry - A simple and efficient protocol has been described for the synthesis of [1,2,4]triazolo[4,3-a]pyri­dines and 3,5-disubstituted-1,2,4-oxadiazoles by...     

Improving stability and thermal properties of TiO2-based nanofluids for concentrating solar energy using two methods of preparation

Journal of Thermal Analysis and Calorimetry - Nanofluids are considered a promising alternative to the classic fluids used in heat transfer processes. One interesting application of nanofluids is...     

Nature and strength of weak intermolecular interactions with metal atoms in crystals of square-planar nickel(<Emphasis Type="SmallCaps">ii</Emphasis>) complexes

The results of geometric analysis of 588 crystal structures of square-planar nickel complexes containing short intermolecular Ni…X contacts (X is a non-metal atom) are reported. The frequency of occurrence of Ni…X interactions of a particular type was evaluated depending on the nature of the X atom and geometric characteristics. The promolecular functions RDG and sign(λ₂)?ρ(r) were used to analyze the character of Ni…X interactions in attractive/repulsive terms. The relative strength of these interactions was determined as the function of the nature of the X atom and the direction of charge transfer.     

Quantum chemical studies of azoles

The results of theoretical search for model transition states of the electrophilic substitution reaction in 2H-tetrazole (1) without the preliminary formation of N-protonated azolium salts are presented for two routes that were previously suggested by the authors and thermodynamically investigated: A, the attack of molecule 1 by the nucleophile (HO^–(aq)) to form the anion to which the electrophile H₃O⁺(aq)) is added and B, the attack of molecule 1 by the same electrophile followed by the addition of the same nucleophile to the specifically solvated protonated species formed in the preceding reaction step. The calculations were performed using the DFT/B3LYP/6-31G(d) method and the scanning procedure of the potential energy surface (PES). Both steps of route A turned out to be nearly barrierless, while in route B only its first step is barrierless and the second one is conjugated with passing an activation barrier of ～45 kcal mol^–1 between non-interacting or weakly interacting reactants and electrophilic substitution products. Unlike the specifically solvated protonated species of 1H-tetrazole in an aqueous solution, a similar species of 2H-tetrazole does not form a prereaction complex with the attacking nucleophile (HO^–(aq)) and the five-membered ring is destroyed in fact in the nitrogen-containing reaction product formed after passing the activation barrier. The optimized structure of the transition state differs strongly from the nitrogen-containing structure of the reaction product with the destroyed ring, which was found by scanning of the PES.     

Carane amino alcohols as organocatalysts in asymmetric aldol reaction of isatin with acetone

Carane-derived β-amino alcohols with amino and hydroxy groups at positions 3 and 4 differing in their mutual arrangement and configuration were synthesized. Their application as organocatalysts in the asymmetric aldol reaction of isatin with acetone allowed one to obtain adducts with up to 84% enantiomeric excess.