Electrochemical thiocyanation of dodecahydro-7,8-dicarba-<Emphasis Type="Italic">nido</Emphasis>-undecaborate and 7,8-dimethyldecahydro-7,8-dicarba-<Emphasis Type="Italic">nido</Emphasis>-undecaborate monoanions

Electrochemical thiocyanation of the dodecahydro-7,8-dicarba-nido-undecaborate and 7,8-dimethyldecahydro-7,8-dicarba-nido-undecaborate monoanions afforded thiocyanate derivatives of these compounds, which were isolated as alkylammonium salts. The structures of the synthesized compounds were determined by the data from IR, ¹H and ¹¹B NMR, and ¹¹B-¹¹B NMR COSY spectroscopy. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1553–1556, July, 2005.     

Halogenation and thiocyanation of the univalent anion of dodecahydro-7,8-dicarba-nido-undecaborate in a diaphragm electrochemical cell

Iodination, bromination, and thiocyanation reactions of the potassium salt K⁺[7,8-C₂B₉H₁₂]^? are investigated during diaphragm electrolysis. The B(9)-monosubstituted derivatives [9-X-7,8-C₂B₉H₁₁]^? (X = I, SCN) and disubstituted derivatives [9,11-X₂-7,8-C₂B₉H₁₀]^? (X = Br, I) are obtained as alkylammonium salts. The composition and structure of these substances are confirmed by data from elemental analysis and IR and NMR (¹H and ¹¹B) spectroscopy.     

Electrochemical iodination of C-methyl derivatives of dodecahydro-7,8-dicarba-nido-undecaborate anion

By electrochemical iodination of potassium 7-methyl-7,8-dicarba-nido-undecaborate and potassium 7,8-dimethyl-7,8-dicarba-nido-undecaborate, their monoiodine derivatives (extracted as tetramethylammonium salts) are synthesized. Their structure is confirmed by NMR and IR spectra and also by elemental analysis data.     

Electrochemical Halogenation of the Single-Charged Anion of Dodecahydro-7,8-dicarba-nido-undecaborate

By means of electrochemical iodination and bromination of potassium dodecahydro-7,8-dicarba-nido-undecaborate, extracted are monoiodide and monobromide derivatives in the form of alkylammonium salts with preparative yields. Their structure is confirmed by the data of elemental analysis and IR and ¹¹B NMR spectroscopy.     

Synthesis of unsaturated 7,8- and 7,9-di(hydroxymethyl)decahydro-7,8- and-7,9-dicarba-nido-undecaborate(1−) diethers

Dicarba-nido-undecaborate(1–) anions were obtained by treatment of 1,2-di(hydroxymethyl)-1,2-dicarba-closo-dodecaborane(12) diallyl ether, 1,2-di(hydroxymethyl)-1,2-dicarba-closo-dodecaborane (12), and 1,7-di(hydroxymethyl)-1,7-dicarba-closo-dodecaborane(12) with ethanolic solutions of KOH and subsequent reaction of the products with cesium and tetramethylammonium chlorides.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1821–1823, September, 1995.     

Synthesis and structure of halogen derivatives of 9-dimethylsulfonium-7,8-dicarba-nido-undecaborane [9-Me2S-7,8-C2B9H11]

Halogenation of 9-dimethylsulfonium-7,8-dicarba-nido-undecaborane [9-SMe₂-7,8-C₂B₉H₁₁] with N-chlorosuccinimide, bromine and iodine gave the expected corresponding halogen derivatives [9-SMe₂-11-X-7,8-C₂B₉H₁₀], where X = Cl (1), Br (2), I (3). In the bromination reaction, [9-SMe₂-6-Br-7,8-C₂B₉H₁₀] (4) was isolated as a minor product being the first example of substitution at a “lower” belt of the 7,8-dicarba-nido-undecaborate cage. The use of excess of bromine resulted in dibromo derivative [9-SMe₂-6,11-Br₂-7,8-C₂B₉H₉] (5). Structures of the compounds prepared were determined using ¹¹B-¹¹B COSY NMR spectroscopy (for all halogen derivatives) and single crystal X-ray diffraction (for compounds 2, 3, and 5).     

Synthesis and reactivity of 4,5-[1,2-dicarba-closo-dodecaborano(12)]-1,3-diselenacyclopentane: opening of the icosahedron to give a zwitterionic intermediate and conversion into 7,8-dicarba-nido-undecaborate(1-)

The reaction of the 1,2-diselenolato-1,2-dicarba-closo-dodecaborane(12) dianion [1,2-(1,2-C(2)B(10)H(10))Se(2)](2-) with dichloromethane (CH(2)Cl(2) or CD(2)Cl(2)) in the presence of donor solvents gave 4,5-[1,2-dicarba-closo-dodecaborano(12)]-1,3-diselenacyclopentane, the title compound, which was characterized by X-ray structural analysis and NMR spectroscopy ((1)H, (11)B, (13)C, and (77)Se). In the presence of pyridine, opening of the icosahedron took place, and a zwitterionic intermediate was isolated and fully characterized in the solid state by X-ray diffraction and in solution by multinuclear magnetic resonance techniques. Although such types of intermediates, prior to deboronation of the ortho-carborane cage, have been proposed several times, this is first example for which the structure has been confirmed unambiguously. This intermediate possesses a nido structure and contains a 7,8-dicarba-nido-undecaborate(1-) anion and a boronium cation, the latter with two pyridine rings linked to the boron atom, which has been extruded from the cage. It was shown that this process is reversible as long as the deboronation is not complete. The formation of the intermediate is accompanied by deboronation, which leads to the 7,8-dicarba-nido-undecaborate(1-) anion. The latter was prepared independently by conventional routes from the title compound, isolated as crystalline material as the tetrabutyl ammonium salt, and characterized by X-ray structural analysis and multinuclear magnetic resonance spectroscopy ((1)H, (11)B, (13)C, and (77)Se).     

Reaction of chloromercuriocobaltacarborane with derivatives of the undecaborate anion

The reactions of the undecaborate anion Cs⁺C₂B₉H₁₂ ^– (1) and exo-nido-ruthenacarborane exo-nido-5,6,10-[Cl(Ph₃P)₂Ru]-5,6,10-(-H)₃-10-H-7,8-C₂B₉H₈ (2) with the 9-chloromercurated cobaltacarborane, viz., 3-(⁵-Cp)-9-ClHg-3,1,2-CoC₂B₉H₁₀ (3), afforded Cs[10-{3"-(⁵-Cp)-3",1",2"-CoC₂B₉H₁₀-9"-Hg}-7,8-C₂B₉H₁₁] (4) and 5,6,10-exo-nido-[Cl(Ph₃P)₂Ru]-5,6,10-(-H)₃-10-{3"-(⁵-Cp)-3",1",2"-CoC₂B₉H₁₀-9"-Hg}-7,8-C₂B₉H₈ (5), respectively. The latter compound exists as two isomers. Compound 5 was prepared also by the reaction of compound 4 with Ru(PPh₃)₃Cl₂.     

Synthesis of 3-isocyano-nido-7,8-dicarbaundecaborate salts and their use as new isonitrile ligands in transition-metal complexes

The treatment of 3-isocyano-o-carboranes with an alkali solution in alcohol results in the regioselective splitting out of a boron atom from position 6 of theo-carborane nucleus to give 3-isocyano-nido-7,8-dicarbaundecaborate salts, in which the isonitrile group is attached to the boron atom of thenido-polyhedron anion. 3-Isocyano-nido-7,8-dicarbaundecaborate salts are new isonitrile ligands in transition-metal complexes. Complexes with chromium, molybdenum, tungsten, and iron compounds have been obtained.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1458–1460, August, 1993.     

Destruction ofB-polyfluorosubstitutedo-carboranes into anions ofB-fluorosubstitutednido-7,8-dicarbaundecaborates by the action of ethanolic alkali and amines

The destruction ofB-polyfluorosubstitutedo-carboranes by the action of ethanolic alkali and amines was studied. The destraction of trifluoro-o-carborane was found to occur regioselectively. The nature of the amine was shown to affect the stereochemistry of the destruction of trifluoro-o-carborane. The intermediate of the reaction of tetrafiuoro-o-carborane with diethylamine was detected.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1141–1145, June, 1995.     

Synthesis and characterization of three nickel(ii) carborane complexes containing nido- or closo-carborane diphosphine ligand

Three nickel(II) carborane complexes, [Ni₂(μ-Cl)₂{7,8-(PPh₂)₂-7,8-C₂B₉H₁₀}₂] (1), [Ni{7-(OPPh₂)-8-(PPh₂)-7,8-C₂B₉H₁₀}{7,8-(PPh₂)₂-7,8-C₂B₉H₁₀}] (2) and [NiBr₂{1,2-(PPh₂)₂-1,2-C₂B₁₀H₁₀}] · CH₂Cl₂ (3), have been synthesized by the reactions of 1,2-bis(diphenylphosphino)-1,2-dicarba-closo-dodecaborane with NiCl₂ · 6H₂O or NiBr₂ · 6H₂O in ethanol under different conditions, respectively. For complex 1, it could also be obtained under the solvothermal condition. All the three complexes were characterized by elemental analysis, FT-IR, ¹H and ¹³C NMR spectroscopy and X-ray structure determination. Single crystal analysis shows that the molecular symmetry of complex 1 is centrosymmetric, containing two same structure units - Ni(7,8-(PPh₂)₂-7,8-C₂B₉H₁₀) linked by two bridged-Cl atoms. The central square plane formed by the [Ni₂Cl₂] unit is almost parallel to the two side NiPP planes. For complex 2, the coordination environment of the Ni atom is a seriously distorted square-planar, in which two positions come from the chelating diphosphine ligand [7,8-(PPh₂)₂-7,8-C₂B₉H₁₀]⁻ degraded from the closo species, while the other two are occupied by an unsymmetrical chelating phosphine oxide ligand [7-(OPPh₂)-8-(PPh₂)-7,8-C₂B₉H₁₀]⁻. As for complex 3, the geometry at the Ni atom is a slightly distorted square-planar. The closo carborane diphosphine ligand 1,2-(PPh₂)₂-1,2-C₂B₁₀H₁₀ was coordinated bidentately to the metal ion through the two phosphorus atoms, and the two Br atoms are at cis position which can fulfill the four coordination mode of the metal.     

Synthesis and structure of new carborane-substituted cyclotriphosphazenes

The reactions of [N(3)P(3)Cl(6)] with one, two, or three equivalents of the difunctional 1,2-closo-carborane C(2)B(10)H(10)[CH(2)OH](2) and K(2)CO(3) in acetone have been investigated. These reactions led to the new spiro-closo-carboranylphosphazenes gem-[N(3)P(3)Cl(6-2n)[(OCH(2))(2)C(2)B(10)H(10)](n)] (n=1 (1), 2 (2)) and the first fully carborane-substituted phosphazene gem-[N(3)P(3)[(OCH(2))(2)C(2)B(10)H(10)](3)] (3). A bridged product, non-gem-[N(3)P(3)Cl(4)[(OCH(2))(2)C(2)B(10)H(10)]] (4), was also detected. The reaction of the well-known spiro derivatives [N(3)P(3)Cl(2)(O(2)C(12)H(8))(2)] and [N(3)P(3)Cl(4)(O(2)C(12)H(8))] with the same carborane-diol and K(2)CO(3) in acetone gave the new compounds gem-[N(3)P(3)(O(2)C(12)H(8))(3-n)[(OCH(2))(2)C(2)B(10)H(10)](n)] (n=1 (5) or 2 (6), respectively), without signs of intra- or intermolecularly bridged species. Upon treatment with NEt(3) in acetone, compound 5 was converted into the corresponding nido-carboranylphosphazene. However, the reaction of gem-[N(3)P(3)(O(2)C(12)H(8))(2)[(OCH(2))(2)C(2)B(10)H(10)]] (5) with NEt(3) in ethanol instead of acetone proceeded in a different manner to give the new compound (NHEt(3))(2)[N(3)P(3)(O(2)C(12)H(8))(2)(O)[OCH(2)C(2)B(9)H(10)CH(2)OCH(2)CH(3)]] (7). For compounds with two 2,2'-dioxybiphenyl units, gem-[N(3)P(3)(O(2)C(12)H(8))(2)[(OCH(2))(2)C(2)B(10)H(10)]] (5), (NHEt(3))[N(3)P(3)(O(2)C(12)H(8))(2)[(OCH(2))(2)C(2)B(9)H(10)]] (8), and (NHEt(3))(2)[N(3)P(3)(O(2)C(12)H(8))(2)(O)[OCH(2)C(2)B(9)H(10)CH(2)OCH(2)CH(3)]] (7), a mixture of different stereoisomers may be expected. However, for 5 and 7 only the meso compounds seem to be formed, with the same (R,S)-configuration as in the precursor [N(3)P(3)Cl(2)(O(2)C(12)H(8))(2)]. The reaction of 5 to give 8 seems to proceed with a change of configuration at one phosphorus center, giving a racemic mixture. The crystal structures of the nido-carboranylphosphazenes 7 and 8 have been confirmed by X-ray diffraction methods.     

Synthesis and NMR spectroscopy investigations of functionalized 8,8,10-trimethyl-4-phenyl-7,8-dihydro-2<Emphasis Type="Italic">H</Emphasis>,6<Emphasis Type="Italic">H</Emphasis>-pyrano[3,2-<Emphasis Type="Italic">g</Emphasis>]chromene-2,6-diones and their spirothiadiazole derivatives

New functionalized derivatives of 8,8,10-trimethyl-4-phenyl-7,8-dihydro-2H,6H-pyrano[3,2-g]-chromene-2,6-dione – analogues of the natural compound graveolone – possessing hydrazine, hydroxylamine, and thiosemicarbazide residues were synthesized and their reactions with acetic anhydride were studied. The structure of the obtained compounds was confirmed by NMR spectroscopy. Correspondence: Viktoria Moskvina, Chemistry Department, Kyiv National Taras Shevchenko University, 60, ul. Vladimirskaya, 01033 Kyiv, Ukraine.     

Synthesis of carboranyl derivatives of deuteroporphyrin IX

Carboranylporphyrins, which can be used in boron neutron-choture therapy of cancer, were prepared from natural deuteroporphyrin IX, 3-amino-o-carborate, and 9-hydroxymethyl-m-carborane. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2337–2339 December, 1999.     

Synthesis of some functional derivatives ofo- andm-carboranes

Amides, amines, and alcohols were synthesized from 9-o- and 9-m-carboranecarboxylic chlorides. It follows from comparison of the¹H NMR spectra ofN,N-dimethyl-1-o- and-1-m-carboranecarboxamides andN,N-dimethyl-9-o- and -9-m-carboranecarboxamides that -bonding of the carborane polyhedron with the carbonyl group in 1-carboranyl dimethylamides is stronger than that in 9-carboranyl dimethylamides. Oxidation of 9-hydroxymethyl-m-carborune with pyridinium chlorochromate gives 9-m-carboranylmethyl 9-m-carboranecarboxylate.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 719–721, March, 1996.     

Fluorosubstituted rhodacarboranes 3,4-(R3P)2-3-H-3,1,2-RhC2B9H11−n F n (n=1, 2, 4): Synthesis, molecular structure, and catalytic properties in hydrosilylation of styrene and phenylacetylene

Hydridorhodacarboranes 3,3-(Ph₂RP)₂-3-H-3,1,2-RhC₂B₉H_11−n F _n (R=Ph, Me;n=1, 2, 4) containing F atoms at the B atoms of the π-carborane ligand were synthesized from (Ph₃P)₃RhCl or (Ph₂MeP)₃RhCl andnido-7,8-C₂B₉H_12−n F _n ⁻ (n=1, 2, 4) salts. Hydridorhodacarboranes 3,3-(Ph₂MeP)₂-3-H-3,1,2-RhC₂B₉H_11−n F _n readily exchange the H atom at the Rh atom for the Cl atom under the action of CH₂Cl₂ to give 3,3-(Ph₂MeP)₂-3-Cl-3,1,2-RhC₂B₉H_11−n F _n . The structures of the 3,3-(Ph₃P)₂-3-H-3,1,2-RhC₂B₉H₇F₄ and 3,3-(Ph₂MeP)₂-3-Cl-3,1,2-RhC₂B₉H₉F₂ complexes were determined by X-ray diffraction analysis. Catalytic properties of the rhodacarbonanes obtained in hydrosilylation of styrene and phenylacetylene by PhMe₂SiH were studied. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 570–578, March, 1997.     

Synthesis of bridged isoflavone derivatives

Summary 7-Chloroalkoxyisoflavones (10–26) have been prepared by chemoselective-in the case of 5,7-dihydroxyisoflavones also regioselective-alkylation of hydroxyisoflavones (3–9) with -bromo--chloroalkanes. Compounds10–26 were allowed to react either with 2,4-dihydroxy-3-n-propylacetophenone (1) or with 2-ethoxycarbonyl-7-hydroxy-8-n-propylchromone (2) to afford bridged isoflavone derivatives27–51 with methylene spacers of various length. Carboxylic acid ethyl esters43–51 have been saponified to obtain the carboxylic acids52–60.

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Darstellung überbrückter Isoflavonderivate

Zusammenfassung Die chemoselektive und bei den 5,7-Dihydroxyisoflavonen auch regioselektive Alkylierung von Hydroxyisoflavonen3 bis9 mit -Brom--chloralkanen ergibt 7-Chloralkoxyisoflavone10 bis26. Die Umsetzung des 2,4-Dihydroxy-3-n-propylacetophenons und 2-Ethoxycarbonyl-7-hydroxy-8-n-propylchromons mit den Verbindungen10 bis26 liefert die überbrückten Isoflavone27 bis51 mit einem Methylen-Spacer verschiedener Länge. Die Verseifung der Ester43 bis51 führt zu den Carbonsäuren52 bis60.

     

Synthesis of dihalocarbene derivatives of estafiatin guaianolide

Adducts of dihalocarbenes generated from chloroform and bromoform were prepared by reaction with estafiatin guaianolide. Their structures were established by XSA. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 453–455, September–October, 2007.     

Synthesis of cyasteronylthiocarbamate derivatives

Ecdysterone, cyasterone, ajugalactone, ajugasterone B, 22-acetylcyasterone, and turkesterone were isolated from leaves of Ajuga turkestanica (Labiatae). Their structures were established using spectral and chemical data. The 2,3,22-triacetate, 2,3,22-tri-O-p-iodobenzoylthiocarbamate, and 2-O-p-iodobenzoylthiocarbamate derivatives of cyasterone were synthesized. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 449–451, September–October, 2006.