Reaction of exo-nido-ruthenacarborane [Cl(Ph3P)2Ru]-5,6,10-(μ-H)3-10-H-7,8-C2B9H8 with bromine

The reaction of bromine with exo-nido-ruthenacarborane [Cl(Ph₃P)₂Ru]-5,6,10-(-H)₃-10-H-7,8-C₂B₉H₈ (1) led to the replacement of the chlorine atom by the bromine atom in the octahedral environment of the ruthenium atom rather than to the substitution in the carborane cage. The structure of [Br(Ph₃P)₂Ru]-5,6,10-(-H)₃-10-H-7,8-C₂B₉H₈ was established by NMR and IR spectroscopy and X-ray diffraction analysis.     

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.     

Facile formation of exo-nido→closo-rearrangement products upon the replacement of PPh3 ligands with bis(diphenylphosphino)alkanes in “three-bridge” ruthenacarborane 5,6,10-[RuCl(PPh3)2]-5,6,10-(μ-H)3-10-H-exo-nido-7,8-C2B9H8

The replacement of the PPh₃ ligands in “three-bridge” exo-nido-ruthenacarborane 5,6,10-[RuCl(PPh₃)₂]-5,6,10-(μ-H)₃-10-H-exo-nido-7,8-C₂B₉H₈ with diphosphines, viz., 1,3-bis(diphenylphosphino)propane (dppp) or 1,4-bis(diphenylphosphino)butane (dppb) dramatically decreases the barrier to the thermal exo-nido→closo rearrangement affording the chelate closo-complexes 3,3-[Ph₂P(CH₂)_nPPh₂]-3-H-3-Cl-closo-3,1,2-RuC₂B₉H₁₁ (n = 3 or 4) under mild conditions. In the reaction with dppp, the rearrangement is accompanied by the formation of 17-electron paramagnetic closo-ruthenacarborane 3,3-[Ph₂P(CH₂)₃PPh₂]-3-Cl-closo-3,1,2-RuC₂B₉H₁₁, which could be isolated as the main product when the reaction was carried out at 80 °C. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2455–2459, November, 2005.     

Electrophilic substitution in eleven-vertex metallacarborane 1,2,4-CpCoC2B8H10

Bromination and mercuration of cobaltacarborane 1,2,4-CpCoC₂B₈H₁₀ were investigated. Mercuration under mild conditions (Hg(OCOCF₃)₂ in CH₂Cl₂) afforded the only monomercurated complex containing the mercury atom at position 6. Bromination gave rise to 3-mono-, 6-mono-, or 6,9-disubstituted derivatives depending on the reaction conditions. The mercurated derivative was studied by the X-ray diffraction method.     

Reaction of hydroxyiminoacetophenone withp-toluenesulfonyl chloride and an X-ray diffraction study of the reaction product

2-Benzoyloxy-2-phenylmalononitrile is formed instead of the expected oxime tosylate in the reaction of hydroxyiminoacetophenone withp-toluenesulfonyl chloride. The structure of the product was confirmed unambiguously by X-ray diffraction analysis. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 872–874, April, 1997.     

Reaction of the Na salts of 2-amino-6-methyl-4-hydroxypyrimidine with bis(bromomethyl)phosphinic acid

The reaction of the Na salts of 2-amino-6-methyl-4-hydroxypyrimidine and bis(bromomethyl)phosphinic acid gave 3,5-dioxo-1,2,3,4,5,8-hexahydro-7-methyl-1,8-diaza-4a-azonia-3-phosphanaphthalene-3-olate, whose structure was determined by X-ray diffraction study. The molecule has a bipolar structure, in which a positive charge is delocalized on the guanidine fragment and a negative charge is on the phosphinic acid fragment.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1125–1128, June, 1995.     

Reaction of 4,6-bis(tert-butyl)-2,2,2-trichlorobenzo[d]-1,3,2-dioxaphosphole with phenylacetylene. ipso-Substitution of the tert-butyl group

The reaction of 4,6-bis(tert-butyl)-2,2,2-trichlorobenzo[d]-1,3,2-dioxaphosphole with phenylacetylene follows the mechanism of ipso-substitution of the tert-butyl group that is in para-position relative to the endocyclic O atom of the heterocycle, predominantly yielding 8-(tert-butyl)-2,6-dichloro-2-oxo-4-phenylbenzo[e]-1,2-oxaphosphorinine (NMR data). The structure of its hydrolysis product, 8-(tert-butyl)-6-chloro-2-hydroxy-2-oxo-4-phenylbenzo[e]-1,2-oxaphosphorinine, was proved by X-ray diffraction analysis.     

Reaction of dodecacarbonyltriruthenium with cinnamaldehyde

The reaction of dodecacarbonyltriruthenium with cinnamaldehyde yielded a mixture of the known H₄Ru₄(CO)₁₂, H₂Ru₄(CO)₁₃, and H₂Ru₆(CO)₁₈, and Ru₆C(CO)₁₇ clusters and the 1,1,1,2,2,2,3,3,3-nonacarbonyl-1,2;1,3-(μ₃-dihydrido)-1,3-σ;2-π-[μ₃-η²-(pheny)vinylidene]triangulotriruthenium complex. The structure of the last-mentioned compound was established by X-ray diffraction study. The mechanism of the reaction and a possible pathway of formation of the vinylidene complex are discussed. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1008–1011, May, 1998.     

Synthesis of bis-cyclopentadienyl compounds with a 9,9-fluorenylidene bridge. Crystal and molecular structure of [μ-9,9-Flu(η5-Cp)2]ZrCl2

An efficient synthetic approach to 9,9-bis(cyclopentadienyl)fluorenes was developed. The two correspondingansa-zirconocenes were synthesized. The structure of one of these compounds was established by X-ray diffraction analysis. Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1290–1294, July, 2000.     

Reaction of 1H-azoles with 2-hydroxybenzyl alcohols

Condensation of 1H-azoles with 2-hydroxybenzyl alcohols gave a series 2-(1H-azol-1-ylmethyl)phenols. 12H-Benzimidazo[2,1-b][1,3]benzoxazine was synthesized from 2-methylmercaptobenzimidazole and 2-hydroxybenzyl alcohol. The X-ray diffraction data of 7-nitro-2,3-diphenyl-5H-imidazo[2,1-b]-[1,3]benzoxazine are discussed. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, 1256–1263, August, 2007.     

Synthesis and configurational assignment of diastereomers ofcloso-3,3-[η2,3-(2-methylenebicyclo[2.2.1]hepta-2,5-dien-2-yl)]-1-benzyl-3,1,2-dicarbollylrhodium complexes

The previously synthesized mixture of diastereomeric complexescloso-3,3-(η^2,3-C₇H₇CH₂)-1-(PhCH₂)-3,1,2-RhC₂B₉H₁₀ was separated by TLC on silica gel into individual diastereomers, whose stereochemistry and relative configurations were determined by X-ray diffraction analysis. Triplet- and quadruplet-like signals are marked with an asterisk Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2069–2070, November, 1997.     

Two different crystal and molecular structures for dicarbonyl(η2-cis-cyclooctene)[η6-1,3,5-triethyl-2,4,6-tris-(trimethylsilylmethyl)-benzene]molybdenum(0): a highly crowded but surprisingly stable molecule

Summary Two crystal and molecular structures have been determined for the sterically very crowded molecule dicarbonyl(²-cis-cyclooctene)[⁶-1,3,5-triethyl-2,4,6-tris-(trimethylsilylmethyl)-benzene]-molybdenum(0),3 a und3 b. In structure3 a the crystals are monoclinic, space group P2₁/n, whereas in3 b they are orthorhombic, space group P2₁2₁2₁. In3 a the carbon-carbon double bond of thecis-cyclooctene moiety is almost parallel to the benzene ring plane; in3 b it is inclined at an angle of nearly 15°. In both3 a and3 b the co-ordinatedcis-cyclooctene and arene moieties adopt conformations which are very similar to those calculated to be the ground states of the free molecules.

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Zwei unterschiedliche Kristall- und Molekülstrukturen von Dicarbonyl (²-cis-cycloocten)[⁶-1,3,5-triethyl-2,4,6-tris-(trimethylsilylmethyl)-benzol]molybdän(0): einem hochgespannten aber überraschend stabilen Molekül

Zusammenfassung Von dem sterisch sehr gespannten Molekül Diarbonyl(²-cis-cycloocten)[⁶-1,3,5-triethyl-2,4,6-tris-(trimethylsilylmethyl)-benzol]molybdän(0) wurden zwei unterschiedliche Kristall-und Molekülstrukturen3 a und3 b ermittelt. Die Kristalle von3 a sind monoklin (Raumgruppe P2₁/n), jene von3 b orthorhombisch (Raumgruppe P2₁2₁2₁). In3 a ist die Kohlenstoff-Kohlenstoff Doppelbindung dercis-Cycloocteneinheit nahezu parallel zum Benzolring angeordnet; in3 b ist sie um etwa 15° gekippt. Die Konformationen des koordiniertencis-Cycloocten sowie des Arens sind sehr ähnlich jenen Grundzustandsstrukturen, die für die nichtkoordinierten Moleküle berechnet wurden.

     

Crystal and molecular structures of fluorinated derivatives of C60 fullerene

Two solvates of fluorinated derivatives of C₆₀ fullerene were studied by single-crystal X-ray diffraction analysis. The crystals of fluorinated fullerene solvate C₆₀F₁₈·C₆H₅Me belong to the monoclinic system with the unit cell parameters a = 11.532(2) , b = 21.501(3) , c = 16.261(2) , = 101.798(5)°. The fluorinated fullerene molecule with the approximate symmetry C _3v occupies a general position. The crystals of fluorinated fullerene solvate C₆₀F₄₈·2C₆H₃Me₃ belong to the cubic system (a = 23.138(2) ). The C₆₀F₄₈ molecule occupies the special position with the S ₆ symmetry. The experimental molecular geometry agrees with the results of quantum-chemical calculations.     

Reactions of lithium phenylacetylenide and lithium 3,3-dimethylbut-1-ynide with 3,6-di-tert-butyl-1,2-benzoquinone. Molecular structure of 2,5-di-tert-butyl-8-(3,6-di-tert-butyl-1,2-benzoquinon-4-yl)-8-phenylocta-2,4,6,7-tetraen-1,6-olide

Reactions of 3,6-di-tert-butyl-1,2-benzoquinone with PhC≡CLi and Bu^tC≡CLi are multistage processes. In the first stage, nucleophilic 1,2-addition of the organometallic compound too-benzoquinone occurs to form the corresponding hydroxycyclohexadienone derivative. In polar solvents, the latter undergoes rearrangement through insertion of the oxygen atom into the ring to form a new allenic organolithium compound. The reaction of the newly formed organometallic compound with the initialo-quinone occurs either as a one-electron transfer to yield lithium semiquinolate and a dimerization product,viz., 4,4′-bi(2,5-di-tert-butyl-9,9-dimethyldeca-2,5-dien-7-yn-1,6-olide), or as the 1,4-addition to yield 2,5-di-tert-butyl-8-(3,6-di-tert-butyl-1,2-benzoquinon-4-yl)-8-phenylocta-2,4,6,7-tetraen-1,6-olide. The structure of the latter compound was established by X-ray diffraction analysis and by NMR and IR spectroscopy. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 2, pp. 351–356, February, 1999.     

Natural product chemistry,part 100: The structure of carissone,C15H24O2

Summary C₁₅H₂₄O₂,M=236.2, monoclinic, P 2₁,a=7.229(7),b=14.925 (9),c=6.235 (9) Å, =92.40 (9)°,V=672.1 ų,T=–133 °C,Z=2,D _x=1.17 g cm^–3. The X-ray diffraction analysis of this sesquiterpenoid fromCarissa opaca confirmed the previously proposed constitution of the isolate and, furthermore, allowed precise NMR assignment.

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Naturstoffchemie, 100. Mitt.: Die Struktur des Carissons, C₁₅H₂₄O₂

Zusammenfassung C₁₅H₂₄O₂,M=236.2, monoklin, P 2₁,a=7.229 (7),b=14.925 (9),c=6.235 (9) Å, =92.40 (9)°,V=672.1 ų,T=–133 °C,Z=2,D _x=1.17 g cm^–3. Die Röntgenstrukturanalyse dieses Sesquiterpenoids ausCarissa opaca bestätigte die bereits vorgeschlagene Struktur und erlaubte ferner eine genaue NMR-Zuordnung.

     

Electrophilic substitution reactions of ferracarborane 3-(η5-Cp)-4-SMe2-3,1,2-FeC2B9H10

Mercuration and bromination reactions of ferracarborane 3-(η⁵-Cp)-4-SMe₂-3,1,2-FeC₂B₉H₁₀ (1) were investigated. Mercuration of 1 under mild conditions (mercury trifluoroacetate in dichloromethane) results in 8-monosubstituted mercury derivative as the only reaction product. Depending on the reaction conditions, bromination of 1 results in 8-mono- or 7,8-disubstituted bromo derivatives. The structures of the monomercury and dibromo derivatives of 1 were established by X-ray analysis. Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1609–1615, September, 2000.     

Reactions of aminophenols with formaldehyde and hydrogen sulfide

The reaction of m-aminophenol with CH₂O and H₂S (1: 2: 1 ratio) afforded 2, 12-dioxa-4, 14-dithia-6, 16-diazatricyclo[15.3.1.1^7,11]docosa-1(20), 7(22), 8, 10, 17(21), 18-hexaene in ∼9% yield. Aminophenol o-and p-isomers react with CH₂O and H₂S (1: 3: 2) to form 2-and 4-[4H-1,3,5-dithiazin-5(6H)-yl]phenols in 86 and 71% yields, respectively. In the crystal structure of the latter, molecules contain dithiazine cycles in the chair conformation with the axial hydroxyphenyl group. Molecular packing represents a combination of molecules forming chains due to the OH...S intermolecular hydrogen bond. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 305–308, February, 2006.     

Reaction of cytisine with formalin

The reaction of cytisine with formalin in various solvents was studied. Methylene-bis-cytisine was produced in addition to the expected N-methylolcytisine in all solvents except acetone, in which N-(3-oxobutyl)cytisine was produced. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 579–580, November–December, 2006.     

Reaction of the N-mesylates of 1,3a,4,8b-tetrahydrocyclopenta[b]indoles and 3,4,4a,9a-tetrahydrocarbazoles with dimethyldioxirane and bromine

In reaction with dimethyldioxirane N-mesyl-1,3a,4,8b-tetrahydrocyclopenta[b]indoles and N-mesyl-3,3,4a,9a-tetrahydrocarbazoles mostly form the trans-epoxide. The reaction with molecular bromine leads to the product from halogenation in the aromatic ring, i.e., the corresponding N-mesyl-7-bromo-1,3a,4,8b-tetrahydrocyclopenta[b]indole or N-mesyl-6-bromo-3,4,4a,9a-tetrahydrocarbazole. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1306–1313, September, 2006.     

Crystal and molecular structure of <Emphasis Type="Italic">tris</Emphasis>(<Emphasis Type="Italic">m</Emphasis>-chlorophenyl)phosphine selenide

The crystal and molecular structure of tris(m-chlorophenyl)phosphine selenide, C₁₈H₁₂Cl₃PSe (I), was investigated by X-ray diffraction (XRD) analysis. The trigonal rhombohedral structure of I (space group \(R\overline 3 c\), a = 14.110(2) Å, c = 32.360(4) Å, Z = 12) was solved by direct methods and refined by least squares in an anisotropic approximation (R = 0.029) for 1319 averaged measured reflections (CAD-4 automatic diffractometer, λCuK_α).