The mechanism of the noncatalytic bromination of carboranes was studied experimentally and theoretically. We found that the reactions of o- and m-carboranes 1 and 2 with elemental bromine are first order in the substrate but unusually high (approximately fifth) order in bromine. The calculated energy barriers of these reactions decrease sharply as more bromine molecules are added to the quantum-chemical system. A considerable primary deuterium kinetic isotope effect for the bromination of 2 indicates that the rate-limiting stage is B-H bond breakage. According to quantum-chemical reaction path calculations, the bond breakage proceeds after the intrusion of a bromine atom into the B-H σ-bond. The 9-Br and 9-OH substituents in carborane 1 strongly retard the bromination of the corresponding derivatives. The bromination mechanism of 9-OH-1 is complex and includes neutral, deprotonated, and protonated forms of the carborane. The high experimental kinetic reaction order in bromine, together with quantum chemical modeling, points to a specific mechanism of bromination facilitated by anionic bromine clusters which significantly stabilize the transition state.

The oxidation of 1,2-C 2 B 10 H 12 (1) with 100% nitric acid was studied in two solvents (CH 2 C1 2 and CCl 4 ). Under the action of superacid (CF3SO3H), the compound 9-HO-1,2-C 2 B 10 H 11 (2) gives the onium cation 9-H 2 O + -1,2-C 2 B 10 H 11 involved in the salt [9-H 2 O + -1,2-C 2 B 10 H n ]-CF 3 SO 3 − , as demonstrated by u B NMR spectroscopy. The experimental and simulated u B NMR spectra of the cation 9-H 2 O + -1,2-C 2 B 10 H 11 are in satisfactory agreement with each other. In the presence of a base, compound 2 is transferred from an ethereal solution to an aqueous alkaline solution giving the anion 9-O − - 1,2-C 2 B 10 H 11 . The structure of compound 2 was confirmed by 1 H, 11 B, 11 B 1 H, 11 B- 11 B COSY NMR spectroscopy, IR spectroscopy, and gas chromatography mass spectrometry and was additionally established by X-ray diffraction.

Deboration of 1-PhCH 2 -1,2-C 2 B 10 H 11 by heating in ethanolic potassium hydroxide afforded Me 4 N + [7-PhCH 2 -7,8-C 2 B 9 H 11 ] − which was treated with excess halosuccinimide (NCS, NBS) in acetonitrile or with elemental iodine or bromine in methanol to obtain Me 4 N + [7-PhCH 2 -9,11-X 2 -7,8-C 2 B 9 H 9 ] − (X = Cl, Br, I). The reaction of 1-PhCH 2 -1,2-C 2 B 10 H 11 with an equimolar amount of iodine gave a mixture of Me 4 N + ·[7-PhCH 2 -11-I-7,8-C 2 B 9 H 10 ] - and Me 4 N + [7-C 6 H 5 CH 2 -9-I-7,8-C 2 B 9 H 10 ] − at a ratio 1:1.8 due to steric effect of the benzyl substituent. The 11 B chemical shifts of each μ-H tautomer of Me 4 N + [7-PhCH 2 -9,11-X 2 -7,8-C 2 B 9 H 9 ] − (X = H, F, Cl, Br, I) were calculated at the DFT level of theory, and their contributions to the average 11 B NMR spectrum and the corresponding tautomeric equilibrium constants were determined.

A new chlorine-free method for the synthesis of 8,9,12-Cl 3 -1,2-C 2 B 10 H 9 , including autoclave heating for 12 h in carbon tetrachloride in the presence of aluminum chloride at 140-150 °C has been suggested. The presence of 8-CHCl 2 -9,12-Cl 2 -1,2-C 2 B 10 H 9 in the reaction mixture has also been detected by GLC. Deborination of 8,9,12-Cl 3 -1,2-C 2 B 10 H 9 and 8-CHCl 2 -9,12-Cl 2 -1,2-C 2 B 10 H 9 by alkali alcohol solution leads to nido-structures isolated as salts Me 4 N+[1,5, 6-Cl 3 -7,8-C 2 B 9 H 9 ] - and Me 4 N+[1-CHCl 2 -5,6-Cl 2 -7,8-C 2 B 9 H 9 ] - with yields of 41% and 39%, respectively.

In this work DFT simulation of the electron structure of cholesterol containing radionuclide agents (cluster systems of carborane (ortho-1, meta-2, para-3) and fullerenol derivatives) for oncological diseases therapy was carried out. Cluster systems of endohedral backminsterfullerenol C-60 derivatives have a promise perspectives in medical application as radionuclide (Fe 10a, Y 10b, Re 10c, Po 10d, Rn 10e isotope contained) nanosized anticancer agents. According to the cluster stability data obtained by the DFT calculation there is a possibility of their real practical obtainment.

Synthesis procedures for coordination compounds of iron(II) 1,5,6,10-tetra(R)-7,8-dicarba- nido -undecaborates(-1) (carboranes) with tris (pyrazol-1-yl)methane (HC(pz) 3 ) of the composition [Fe{HC(pz) 3 } 2 ]A 2 · n H 2 O (A = (7,8-C 2 B 9 H 12 ) − ( I ), (1,5,6,10-Br 4 -7,8-C 2 B 9 H 8 ) − ( II ), (1,5,6,10-I 4 -7,8-C 2 B 9 H 8 ) − ( III ), n = 0–2) are developed. The compounds are studied by static magnetic susceptibility in the temperature range of 160–500 K, electron (diffuse reflectance spectra), IR, and Mössbauer spectroscopy methods. It is shown that the complexes have high-temperature spin-crossover 1 A 1 ⇔ 5 T 2 . Transition temperatures ( T c ) for I–III are 370 K, 380 K, and 400 K respectively. Spin-crossover is accompanied by thermochromism (color change: pink ⇔ white).

Рассмотрены технологии применения эфирных и сложноэфирных химических связей для получения душистых веществ и биологически активных соединений. Систематизированы экспериментальные данные, полученные в Институте физико-органической химии НАН Беларуси и опубликованные за период 2000–2013 гг. Этерификацией ангидридами и хлорангидридами карбоновых кислот, содержащих в своем составе карборановые, гетероциклические, галоидорганические, пероксидные группы и фрагменты природных соединений растительного происхождения – спиртов, фенолов или оксимов карбонильных соединений, также содержащих ацетиленовые, карборановые, изоксазольные, изотиазольные и другие фармакофорные фрагменты или заместители, были получены соответствующие простые и сложные эфиры. Приведены примеры их практического применения.

A new method for introduction of one and two iodine atoms into the meta-carborane fragments containing carboxy groups at the core carbon atoms C1/C2 was developed. Reaction proceeded in acetic acid at heating in the presence of concentrated nitric and sulfuric acids.

Oximes of β-isatin, isoxazole- and ferrocene-containing ketones, o- and m-carborane alcohols react with isoxazol- and isothiazolecarboxylic acid chlorides in the presence of triethylamine to afford the corresponding esters.

Quantum-chemistry projecting of the carborane and fullerene nano-cluster agents has been carried out. These agents contain or transform into radio-nuclides under the effect of neutron radiation that apply for oncological diagnostics and therapy.

A technique is proposed for directed synthesis of 6,11-dichloro-9-dimethylthio-7,8-dicarba-nido-undecaborane [6,11-Cl2-9-SMe2-7,8-C2B9H9]. Single-crystal X-ray diffraction is used to identify the molecular and crystal structure of the compound.

Potassium 7,8-dicarba-nido-undecaborate was thiocyanated by nondiaphragm electrolysis. The salt Me4N+[9-SCN-7,8-C2B9H11]− was isolated and converted into the trimethylammonium salt using ion-exchange. Methods for the synthesis of water-soluble sodium 7,8-dicarba-nido-undecaborate and its biphasic iodination (for 131I introduction) were developed. Thus, the synthesis and analysis of the radioactive iodine-labeled sodium salt of 11-(131I)-9-thiocyanato-7,8-dicarba-nido-undecaborate were proposed and carried out. The toxicity of the synthesized compound was evaluated. It was established that 100 and 75 mg/kg doses are 100% lethal for test animals while no significant disorders were observed at doses of 35 and 20 mg/kg. The biodistribution of the compound in organs and tissues was studied in mice with melanoma B-16. The maximum accumulation of labeled compound in tumor, skin, muscle, liver, kidneys, and spleen was observed 3 – 6 h after administration. A comparison of drug accumulation in tumor and normal tissues showed that the preparation does not possess pronounced tumor-targeting properties.

A preparative method for the synthesis of m-carborane azomethines via the condensation of mcarborane-C-4-formylphenyl methanoate with aliphatic, cycloaliphatic, and aromatic amines was developed.

A method of preparative synthesis of o(m)-carborane-containing azomethines via the condensation of o(m)-carboranyl-C-methylene-4-formylbenzoates with aliphatic, cycloaliphatic, and aromatic amines was developed.