G. I. Borodkin

Nitrenium Ions and Problem of Direct Electrophilic Amination of Aromatic Compounds

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

Electrophilic reactions of aromatic and heteroaromatic compounds in ionic liquids

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

Quantum-Chemical Study of Nitrosonium Complexes of Monocyclic Aromatic Compounds

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.

Fluorination of aromatic compounds with N-fluorobenzenesulfonimide under solvent-free conditions

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.

Molecular and crystal structure of 1-amino-X-pyrazinium mesitylenesulfonates

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.

Mechanism of Electrophilic Fluorination of Aromatic Compounds with NF-Reagents *

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.

Quantum-chemical study on uracil and thymine nitrosonium complexes

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 (

Nitrosonium complexes of [2.2]paracyclophane

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