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The influence of the nature of the solvent, of the base, the catalyst, the temperature, and the pressure of CO on reactions of aryl and heteryl iodides RI with terminal acetylenes R′C≡CH in the presence of CO, catalyzed by palladium complexes is studied.

1. The C13 NMR spectra were obtained for the isomeric diphenylcarboranes, the dianions of these carboranes, 1,2-dimethyl-o-carborane, its dianion, and also the monoanions. The dianions from the o- and m-carborane are identical but the dianion from the p-carborane differs from them. The carbon nuclei of the carborane polyhedron occupy equivalent positions. 2. The C13 NMR spectra were obtained for the dianion from 1,2-diphenyl-o-carborane in THF at 0, −30, and −50°. There are no changes in the dianion's structure in this temperature rangs. 3. The monoanions, obtained from the isomeric diphenylcarboranes, are identical. The carbon nuclei of the carborane fragment and the phenyl rings in them have a nonequivalent position.

1. A method has been developed for the synthesis of polymeric phosphinocarborane complexes of rhodium(I), based on copolymerization of methyl methacrylate with salts of 1-isopropenyl(3)-1,2-dicarbaundecaborate and subsequent interaction of the resulting polymeric matrix with tris(triphenylphosphine)rhodium chloride. 2. It has been shown that the phosphinocarborane complexes of rhodium(I) have high activities in the hydrogenation and isomerization of olefins and diolefins.

1. The NMR-13C spectra of the o-, m-, and p-isomers of dicarbaclosododecaborane-(12), carbaphosphaclosododecaborane-(12), carbaarsaclosododecaborane-(12), and l,10-dicarbaclosodecaborane-(10) were investigated, and the chemical shifts13C and spin-spin interaction constants SSIC JC-H and JC-P were determined, along with δ31p of the isomeric carbaphosphaclosododecaboranes-(12). The shift of13C and JC-H of carboranes is weakly influenced by such solvents as DMSO, THF, acetone, CH2Cl2, and CHCl3. 2. A correlation is observed between the SSIC of JC-H and the effective charge of the carbon atom of the carboranes. The values of JC-H are evidence of a hybridization of the orbital of carbon in the C-H bond in carboranes intermediate between sp- and sp2-hybridization, close to sp2. 3. Spin-spin interaction between the13C and31P nuclei, separated by boron atoms, is observed in the m-isomer and is not observed in p-phosphacarborane.

1. Carboranes of the type C2BnHn+2 (n=6−10) have only an inductive effect when acting as substituents in a benzene ring. 2. Considerable deshielding of13C nuclei is observed in the case of the C atoms bonded to the phenyl substituent in carboranes of the type C2BnHn+2. 3. The change in the13C chemical shifts of the CH group in the investigated phenyl-substituted carboranes depends on its position with respect to the C atom bonded to the substituent: weak deshielding is observed in the o-position; practically no effect is observed in the m-position; and shielding increases in the p-position.

Kinetic acidities of aryl and benzyl CH-bonds for complexes of benzene and its methoxy and alkyl derivatives with tricarbonylchromium are determined in a solution of lithium tert-butoxide in N,N-dimethylacetamide. Complexation of alkyl-aromatic compounds to the Cr(CO)3 group increases the lability of the aryl CH-bond by 107–109 times and that of the benzyl bond by 5·104–5·105 times. The Cr(CO)3 group in arene complexes neutralizes the effect of other substituents regardless of their nature and position in the molecule.

1. The concentration equilibrium constants of the reactions of metalation of the CH bonds of o- and m-barene and their methyl- and phenyl-derivatives by carbanions of a number of hydrocarbons and phenylxanthene in 1,2-dimethoxyethane were determined by spectrophotometric measurements, and the values of pKa of the thermodynamic acidities of barenes were calculated. 2. An estimate of pKa of 1-methyl-o-barenes, followed by bromination and carbonization of equilibrium systems and the use of gas-liquid chromatography. 3. The kinetic acidities of the CH bonds of m-barene and its methyl- and phenyl-derivatives were determined by measuring the kinetics of the reactions of isotopic exchange of hydrogen with liquid deuterated ammonia. 4. The higher acidity of o-barenes in comparison with m-barenes was confirmed. 5. The possible influence of specific solvation on the value of pKa of barenes was hypothesized.

1. The heats of combustion, formation, and sublimation of o- and m-carboranes were determined. 2. The difference in the energies of formation of o- and m-carboranes, equal to 16 kcal/mole, was found experimentally. 3. It was confirmed experimentally that o-carborane is thermodynamically less stable than m-carborane.

1. In an investigation of the PMR spectra of methylmercury derivatives of ortho-, meta-, and paracarboranes, substantial variations of the spin-spin interaction constants JHg199-C-H1 were found as a function of the structure of the compound and the nature of the medium. 2. The values of JHg199-C-Hg1 in substituted ortho-carboranes\(\begin{array}{*{20}c} {R - C - C - HgCH_3 } \\ {\begin{array}{*{20}c} \backslash & / \\ \end{array} } \\ {B_{10} H_{10} } \\ \end{array}\) are satisfactorily correlated with the induction constants of the substituents R. 3. The sensitivity of the indicator group HgCH3 to the polar influence of substituted ortho-carboranes depends on the solvent, decreasing in the series CH2Cl2>dioxane>pyridine >dimethyl sulfoxide. 4. The presence of intramolecular coordination of certain substituents (R=C6H5CH2, CH3OCH2) with the metal atom of the indicator group HgCH3 was ascertained in substituted ortho-carboranes. 5. The sequence of increasing electronegativity of certain carboranyl radicals was established: $$\begin{array}{*{20}c} {o - HCB_{10} H_{10} C - CH_2< p - HCB_{10} H_{10} C -< m - HCB_{10} H_{10} C - } \\ {< m - PB_{10} H_{10} C -< o - HCB_{10} H_{10} C -< o - CH_3 - C(3 - F)B_{10} H_9 C -< o - CH_3 - C(9,12 - Cl_2 )B_{10} H_8 C - .} \\ \end{array}$$ 6. The dependence of the electron donor properties of the CH3Hg group on the selection of the solvent was demonstrated.

1. The electrophilic monohalogenation of barene proceeds predominantly in the 9(12)-position of the barene nucleus, in which connection 3–10% of the 8-halobarene is formed. 2. The electrophilic monohalogenation of 1-methylbarene proceeds to equal degree in the 9- and 12-positions of the barene nucleus with the formation of the 1-methyl-9- and 1-methyl-12-halobarenes, in which connection 5–10% of the 1-methyl-8-halobarene is also formed. 3. Together with the predominant formation of the 9, 12-isomer, appreciable amounts of the 8, 9-isomer (20–30%) and a trace amount of the 8,10-isomer (1%) are formed in the electrophilic dihalogenation of barene and 1-methylbarene. 4. The electrophilic halogenation of neobarene proceeds more selectively than in the case of barene, and leads to the formation of mainly the 9(10)-halobarene and 9,10-dihalobarene. 5. All of the possible monohaloneobarenes are formed in the radical halogenation of neobarene.

1. Neobarenes are isomerized to barenes via the dianions of the dicarbadodecaboranes (14), in which connection the isomerization must be regarded as being a three-step process: a) reduction, b) isomerization of the dianion, and c) oxidation. 2. The dianions of the dicarbadodecaboranes (14) form barenes when treated with oxidizing agents. 3. The rapid addition of two equivalents of the metal occurs when the neobarenes are treated with alkali metals in liquid ammonia, with the formation of the adduct (m-B10H10C2RR′)2M, which is easily isomerized to the adduct (o-B10H10C2RR′)2M. 4. The transfer of two electrons to the barene or neobarene nucleus occurs when the barenes or neobarenes are treated with aromatic anion-radicals of the type of naphthalenesodium in tetrahydrofuran solution, with the formation of the dianions.

1. The thermal rearrangement of the halogen in 9-halobarenes and 9-haloneobarenes yields all of the possible B-halobarenes and B-haloneobarenes. 2. The thermal rearrangement rate of the halogen in the 9-haloneobarenes is considerably slower than that of the halogen in the 9-halobarenes. 3. The rearrangement rate of the halogen in the haloneobarenes depends on the nature of the halogen. 4. The isomerization of the 9,12-dihalobarene, 8, 9,12-trihalobarene and 8, 9,10,12-tetrahalobarene proceeds with the formation of mixtures containing most of the corresponding isomeric haloneobarenes. 5. It was shown that the intermolecular exchange B-H+B-I⇌B-I+B-H takes place in the barenes. 6. The rate with which the hydrogen atom in the different positions of the neobarene nucleus is replaced during electrophilic halogenation decreases in the order: 9,10≫5,12>4,7,8,11≫2,3.

1. The IR spectra of compounds of the barene and neobarene series were obtained, and the assignment of certain frequencies was given. 2. The integral intensity of the band corresponding to the characteristic valence C-H vibration (ICH) was measured in the IR spectra of more than 50 compounds. 3. Successive introduction of halogen atoms at the boron atoms of the barene and neobarene ring leads to a gradual increase in ICH. 4. The influence of the substituent X in the system o-XCB10H10CH upon the C-H bond is transmitted according to an induction mechanism. A linear relationship between √ICH and the induction constant σi of the substituent X was found. The value derived for σi for the CH2Hg group is −0.20.

1. In a study of the comparative reactivity, it was shown that the acidity of the C-H bonds, the electron-acceptor effects of the ring, the ease of electrophilic, radical, and exchange halogenation, the stability of the carboranyl anion, the rate of nucleophilic substitution, the electron affinity of the carborane system, and the rate of cleavage of the C-C bonds in carbonyl derivatives under the action of nucleophilic reagents decrease in the series of o-, m-, and p-carboranes, and the stability to the action of strong bases and oxidizing agents increases. 2. 1-p-Carboranecarboxylic and 1,12-p-carboranedicarboxylic acids were produced by carbonization of mono- and dilithium derivatives of p-carboranes. 3. In the electrophilic halogenation of p-carborane, 2-bromo-p-carborane, and 2-chloro-p-carborane were produced. 4. In the photochlorination of p-carborane, decachloro-p-carborane, p-B10C10C2H2, was produced. 5. The value of the dissociation constant (pK a =3.64) in 50% alcohol was determined for 1-p-carboranecarboxylic acid. 6. The value of the equilibrium acidity (pK a =29.8–29.9 in the McEwen scale) was determined for p-carborane. 7. α-Ketones of the p-carborane series undergo cleavage of the C-C bond under the action of bases. 8. The thermal isomerization of m-carborane to p-carborane is an equilibrium reaction.

1. Some B-aryl-o-carboranes, containing an aryl group in the 4- and 9-positions of the o-carborane nucleus, were obtained for the first time. 2. The 4-o- and 9-o-carboranyl groups are electron-donor substituents according to the induction mechanism.

1. Vinyl- and isopropenyl-o-carborane are hydrogenated under the reaction conditions for the hydroformylation and carboxylation of olefins in the presence of cobalt or rhodium carbonyls. 2. A mechanism was proposed for the hydrogenation of olefin-o-carboranes in alcohol solutions under CO pressure.

In contrast to aminoboranes that contain a tricoordination boron atom, 9-amino-m-carboranes exhibit a reactivity that is close to that of aliphatic and aromatic amines: They are smoothly acylated, alkylated, form substituted ureas with phenyl isocyanate and Schiff bases with aldehydes, and enter into the carbylamine reaction.

The structure of the 1,10-C2B8H10 molecule was determined by the electron diffraction method. The following geometric parameters were obtained for the D4d symmetry model: B-C = 1.60(1) A; B-B (basal) = 1.87(1) A; B-B (equatorial) = 1.80(1) A; B-H = 1.17(3) A and the C-B-H angle = 13(5.7)°. These data are in good agreement with the structure of the B10H102− ion or of the less symmetrical 1,6-C2(CH3)2B8H8 isomer.

The Taft method was used to measure the induction constant for the 1-p-carboranyl group (σi = +0.14). It was shown that this group is an electron-acceptor grouping.

The results of measuring the equilibrium CH acidity of boron-substituted carboranes-12 by the transmetalation method in 1,2-dimethoxyethane show that the effect of the substituent on the methine group of carboranes is transmitted predominantly by the induction mechanism.

1. Syntheses are reported for the first mesionic compounds with a carbon-transition metal σ-bond, namely, σ-sidnonyl-η-cyclopentadienyldicarbonyliron. 2. The capacity of sidnones with a C-Fe bound to undergo cycloaddition with the dimethyl ester of acetylenedicarboxylic acid to give σ-pyrazolyl-η-cyclopentadienyldicarbonyliron was demonstrated.

1. The phenyl-, diphenyl-, benzyl-, and dibenzyl-o-carboranes, and the phenyl-, di-phenyl-, and dibenzyl-m-carboranes form arylcarboranechromium tricarbonyls when heated with Cr(CO)6. Dibenzyl-m-carborane reacts with Cr(CO)6 to give the mono- and binuclear complexes. 2. When heated, the arylcarboranes in arylcarboranechromium tricarbonyls are replaced by diphenyl and stilbene.

Starting from, tertiary amines of the carborane series, cyclic complexes with σ B-Pd bonds have been obtained, which give insertion products with two molecules of diphenylacetylene, at the B-Pd bond.

l. A preparative method has been developed for the synthesis of 1-isocyanato-carboranes, by reaction of carboranecarbonyl chlorides with trimethylsilyl azide. 2. 1-Isocyanatocarboranes display properties characteristic of aliphatic and aromatic isocyanates.

1. The isomerization of the 3-ethynyl- and 3-vinyl-o-carboranes in the gas phase leads to the respective formation of mixtures of the 2- and 4-ethynyl-m-carboranes and the 2- vinyl-m-carboranes. 2. The B-alkenyl-o- and B-alkenyl-m-carboranes enter into the electrophilic addition reaction more easily than the 1-alkenyl-o- and 1-alkenyl-m-carboranes.

1. The spectral characteristics of the C-H valence vibration bands of o-, m-, and p-carboranes have been studied in CCl4 and DMSO solutions. 2. o-, m-, and p-Carboranes form H-bonded complexes of the type RCB10H10CH...O with DMSO. The enthalpy of formation of these complexes, calculated according to the formulae of Iogansen from the frequencies and intensities of the νC-H bands, amounts to 2–3 kcal/mole. 3. The introduction of halogen atoms to the carborane nucleus leads to an increase in the stability of the H-bonded complex in comparison with the unsubstituted carboranes.

1. Polarographic reduction of C-hydrocarbon derivatives and B-haloderivatives of barenes and neobarenes was studied. 2. The barene system has a greater electron affinity than does the neobarene system.

1. The reactions of 1-bromomagnesiomethylbarene with HgCl2, SnCl4, and PCl3 have given di(barenylmethyl)mercury, tetra(barenylmethyl)tin, and tri(barenylmethyl)phosphine. 2. The action of 1-bromomagnesiomethylbarene on (π-C5H5)2TiCl2 has given the stable di(π-cyclopentadienyl)di(σ-barenylmethyl)titanium.

1. The dianion of dicarbadodecaborane (14) is capable of donating electrons to such electron acceptors as p-quinone, benzophenone, fluorenone, and nitrobenzene, giving o-carborane and the corresponding anion radicals of the electron acceptors. 2. There is a transfer of electrons from the dianion of dicarbadodecaborane (14) to substituted o-carborane (1,2-diphenyl-o-carborane, 1-vinyl-o-carborane, and 1-phenyl-o-carborane). 3. The dianion of dicarbadodecaborane (14) reduces the C-Br bond in bromoform and carbon tetrabromide.

1. The bromine and iodine atoms in bromo- and iodobarenes and neobarenes are exchanged by chlorine upon heating them with CuCl. 2. The reactivity of the halogen in barene and neobarene halides is considerably lower compared to the halogen derivatives of a number of benzenes and ferrocenes.

1. The spin-spin coupling constants J199Hg-C-1H were determined for a series of methylmercuric carboranecarboxylates, ferrocenecarboxylate, and cyclopentadienylmanganesetricarbonylcarboxylate. 2. A relation was found between the J199Hg-C-1H values for the methylmercuric carboxylates RCOOHgCH3 and the Taft σ* constants. On the basis of this relation σ* values were calculated for the l-o-, 1-m-, and 1-p-carboranyl groups, ferrocenyl groups, and cyclopentadienylmanganesetricarbonyl groups. 3. The dissociation constants pKa for l-o-, 1-m-, and 1-p-carboranecarboxylic acids were calculated from the JHg-CH3 values.

1. Using the Taft method it was shown that the 1-[1,8-dicarbaclosoundecaborane (11)] group is an electron-acceptor grouping, which exhibits only an induction effect (induction constantσi=0.12; resonance constantσR0=0.00). 2. The opening of the carborane structure to the anion of m-dicarbaundecaborane is postulated when the adduct of 1,8-dicarbaclosoundecaborane (11) with triphenylphosphine is formed, in which connection this grouping exhibits electron-donor properties (σi=−0.24;σR0=−0.15).

1. Anions of neodicarbaundecaboranes(13) are formed smoothly by heating neobarenes with caustic potash in butyl and amyl alcohols, methyl- and ethylcellosolves, and ethylene glycol. 2. On the basis of the oxidative cleavage of phenylneodicarbaundecaborane(13) and phenyldicarbaundecaborane(13), which leads to identical products (tolune, ethylbenzene, styrene, phenylacetylene, benzaldehyde, and acetophenone), the idea of a mutual rearrangement of the ortho and meta structures in the intermediate products of the oxidation of derivatives of neodicarbaundecaborane(13) and dicarbaundeca-borane(13) has been proposed.

1. The double bond in 1-vinylbarene is capable of taking part in electrophilic addition reactions, although it has a considerably lower reactivity thanα-olefins. 2. Hydrogen chloride and bromide add to vinylbarene in the presence of AlCl3 according to Markovnikov's rule with the formation of 1-(α-chloroethyl)barene and l-(α-bromoethyl)barene, respectively. 3. The barene and neobarene nuclei undergo thermal chlorination, which takes place similarly to photochemical chlorination.

1. We obtained the UV absorption spectra of 1-phenyl-o-carborane, 3-phenyl-o-carborane, 1-phenyl-m-carborane, 1,2-diphenyl-o-carborane, 1,7-diphenyl-m-carborane, and also the cesium salt of phenyldi-carbaundecarborane (13) in the 210–340 nm region. 2. The integral intensity of the ∼1600 cm−1 line in the Raman spectra of solutions of 1-phenyl-o-carborane, 1,2-diphenyl-o-carborane, 1-phenyl-m-carborane, and benzotrifluoride in CH2Cl2 was measured. 3. The effect of the carborane nucleus on the UV absorption band of the benzene ring in the 240–280 nm region is expressed in a slight shift of the maximum, with the retention of a distinct vibrational structure and an increase in the molar absorption coefficient up to several hundred units. In contrast, in the UV spectrum of [C6H5CB9H10CH]−Cs+ the intensity of the same band reaches 7700; the vibrational structure is smoothed out completely. 4. On the basis of the UV spectra and the intensities in the Raman spectra of the phenylcarboranes it was concluded that conjugation of the benzene ring with carborane nuclei is absent, and that conjugation with the dicarbaundecarborane (13) anion exists.

1. It was shown on the basis of the reactions of C-bromo- and C-iodo-neobarenes with alcoholic alkali that the bromine and iodine atoms in these compounds have a “positive” character. 2. C-bromo- and C-iodo-neobarenes undergo ready metal-halogen interchange with butyllithium and ethylmagnesium bromide. 3. C-bromo- and C-iodo-barenes undergo ready metal-halogen exchange with butyllithium and ethylmagnesium bromide.

1. A halogen on the carbon atoms of carborane and neocarborane nuclei migrates upon heating to boron atoms with the formation of carborane and B-halocarboranes, and neocarborane and B-haloneocarboranes, respectively. 2. The halogen in the side chain of 1-halomethylcarboranes is able to migrate upon heating to boron atoms, giving 1-methylcarborane and 1-methyl-B-halocarboranes. 3. The B-H bonds of carborane and neocarborane nuclei possess reductive properties.

1. The electronic influence of the 1-[1,6-dicarbalkosodecaborane(10)] (induction constant σi=0.10 and resonance constant σR0=−0.02) and 1-[1,10-dicarbalkosodecaborane(10)] groups (σi=0.05 and σR0=−0.02), which play the role of weak electron-acceptor groups, is manifested chiefly according to an inductive mechanism. 2. The nitration of 1-phenyl-1,10-dicarbalkosodecaborane(10) proceeds primarily in the p-position of the benzene ring.

1. Starting from lithium-p-carboranes, the C-iodo-, mercapto-, benzoyl-, methylmercury-, ni-troso-, and amino-derivatives of p-carborane were obtained, p-Carboranesulfinic acid was also produced. 2. Iodine atoms in C-iodo-p-carborane have a “positive” character. 3. The reactivity of lithium-p-carborane is analogous to that of lithium-m-carborane.

It was found that mercuric chloride has a specific oxidative effect on the anions of dicarbadodecahydronidoundecaborates in THF or pyridine, which consists in the preferential replacement of hydride hydrogen by the ligand in the 8 position of the anion.

A preparative method was proposed for obtaining dihydromorphinones based on the O-demethylation of dihydrocodeinones using the AlCl3·Me2S complex in CH2Cl2.

The 1-(4′-acetylphenyl)-o- and m-carboranes are capable of trimerizational cyclocondensation to give 1,3,5-tri-[(4-carboranyl)-phenyl]benzenes.

1 -Alkylarenechromium tricarbonyls are readily metallated in the benzyl position by the action of alkali metal amines in liquid ammonia. 2. Treatment of theα-metallated alkylarenechromium tricarbonyls with BrCH2CO2Na and subsequent oxidation of the complexes is a preparative method for the synthesis of arylpropionic acids.

A method was developed for the preparation of the 1-cyano-o-and m-carboranes by the reaction of either the C-lithium or C-bromomagnesium o- and m-carboranes with the aromatic esters of cyanic acid.

1-[1,7-Dicarbaclozooctaboran(8)yl] (induction constant σi=0.08 and resonance constant σR°=−0.02) and 1-[1,6-dicarbaclozononaboran(9)yl] (σ=0.09 and σR°=0.05) groups are weak electron-acceptor groupings.

The manometric method was used to study the kinetics of the reaction of phenylacetylene with the complex of decaborane and diethyl sulfide, with the formation of 1-phenyl-o-carborane. The reaction is described by a second order equation.

The equilibrium acidity of potassium dicarbadodecahydronidoundecaborate(−1) when metalated with fluorenylpotassium and indenylpotassium in 1,2-dimethoxyethane was determined, and was found to have a pK a value of 21.1–21.5 on the Streitwieser scale.