G. I. Borodkin

G. I. Borodkin; V. G. Shubin

Published data on direct electrophilic amination of aromatic compounds are summarized and analyzed on the basis of nitrenium ion properties.

G. I. Borodkin; V. G. Shubin

The review summarizes and analyzes published data on electrophilic aromatic substitution reactions performed in ionic liquids.

R. V. Andreev; G. I. Borodkin; V. G. Shubin

With the use of Hartree-Fock and DFT methods we demonstrated that for the benzene derivatives with the substituents Me, Et, Pr, i-Pr, t-Bu, CF3, F, and Cl π-complexes are more favorable by energy, whereas with the substituents CHO, MeCO, PhCO, CN, NO, and NO2n-complexes are more feasible. The affi nity of aromatic compounds to the nitrosonium-cation (ANO+) at the formation of the π-complexes grows with the growing donor character of the substituents in the ring and with their number. The best agreement between the calculated and experimental ANO+ values for benzene was obtained with the use of RI-MP2/L1 method.

R. V. Andreev; G. I. Borodkin; V. G. Shubin

Reactions of N-fluorobenzenesulfonimide with methylbenzenes, phenols, and phenol ethers were studied under solvent-free conditions. The rate constant ratio for the reactions with mesitylene and durene indicates polar mechanism of the process. Solvent-free fluorination of aromatic compounds with N-fluorobenzenesulfonimide in some cases is more selective than reactions with other N-F reagents in a solvent.

R. V. Andreev; G. I. Borodkin; A. Yu. Vorob’ev; Yu. V. Gatilov; V. G. Shubin

X-Ray diffraction analysis was performed of 1-amino-X-pyrazinium mesitylenesulfonates (X=H, 2-NH2, 3-NHCOMe, 3-OMe, 3-Cl). In all events save 1,2-diaminopyrazinium cation the bond length of N-NH2 was shorter than that of N-N bond but considerably longer than the length of the double bond N=N. In the 1,2-diaminopyrazinium cation the bond distance C2-NH2 was close to the length of a common double bond C=N indicating the iminium character of the cation. Quantum-chemical calculations [AM1, PM3, DFT/(PBE/3z), B3LYP/6-31G++(2d,p)] provided the geometry of cations similar to the experimental one. In the crystals under investigation motifs were observed of 0D, 1D, and 2D type mainly due to hydrogen bonds N-H···O and π-stacking interactions of the aromatic rings.

G. I. Borodkin; Pavel A. Zaikin; M. M. Shakirov; V. G. Shubin

Kinetic isotope effects H/D in electrophilic fluorination of aromatic compounds with NF-reagents were investigated. The small values of kH/kD (0.86–1.00) are in agreement with the polar reaction mechanism where the Wheland complex decomposition is not the limiting stage. The fluorination of 1,3,5-trideuterobenzene was established by 1H and 19F NMR spectroscopy to occur with a 1,2-migration of a hydrogen (deuterium) atom. The analysis of Brown-Stock relationship demonstrated that the activity of NF-reagents exceeded that of many known electrophilic systems including halogenation, but it was essentially less than the activity of elemental fluorine.

R. V. Andreev; G. I. Borodkin; V. G. Shubin

AbstractQuantum-chemical calculations at the RI-MP2/L1 level of theory showed that the most energetically favorable complexes of uracil and thymine with nitrosonium cation are those of n-type with NO+ coordination at the nitrogen or oxygen atom. A correlation was found between the experimental and calculated affinities of the dioxo tautomer of thymine for nitrosonium ion (

G. I. Borodkin; I. R. Elanov; V. G. Shubin

G. I. Borodkin; I. R. Elanov; R. V. Andreev; M. M. Shakirov; V. G. Shubin

A_{NO^ + }

R. V. Andreev; G. I. Borodkin; V. G. Shubin