Three-component condensation of 2-naphthylamine with aromatic aldehydes and 5-(2-furyl)-1,3-cyclohexanedione

Three-component condensation of 5-(2-furyl)-1,3-cyclohexanedione with 2-naphthylamine and aromatic or heteroaromatic aldehydes afforded 12-aryl(hetaryl)-9-(2-furyl)-7,8,9,10,11,12-hexahydrobenzo[a]-acridin-11-ones possessing two asymmetric carbon atoms (C⁹ and C¹²). The products were found to be formed as mixtures of diastereoisomers.     

Condensation of quinolin-6-amine with 5-(<Emphasis Type="Italic">p</Emphasis>-methoxyphenyl)-cyclohexane-1,3-dione and substituted benzaldehydes

New 12-aryl-9-(p-methoxyphenyl)-8,9,10,12-tetrahydro-7H-benzo[b][4,7]phenanthrolin-11-ones having two asymmetric carbon atoms (C⁹ and C¹²) were synthesized by three-component condensation of quinolin-6-amine with 5-(p-methoxyphenyl)cyclohexane-1,3-dione and substituted benzaldehydes. According to the ¹H NMR data, the products are mixtures of diastereoisomers.     

(1,3-Diformylindenyl)cyclopentadienyl ruthenium derivatives

The reaction of [CpRu(CH₃CN)₃][PF₆], [Cp*RuCl] _n , and [Cp^FRuCl]n with 1,3-diformylindene results in the predominant formation of zwitter-ionic arene-cyclopentadienyl complexes {η⁶-1,3-(CHO)₂C₉H₅}RuCp (Cp = C₅H₅), {η⁶-1,3-(CHO)₂C₉H₅}RuCp* (Cp* = C₅Me₅), and {η⁶-1,3-(CHO)₂C₉H₅}RuCp^F (Cp^F = C₅Me₄CF₃), respectively. The ruthenocenes {η⁵-1,3-(CHO)₂C₉H₅}RuCp, {η⁵-1,3-(CHO)₂C₉H₅}RuCp*, and {η⁵-1,3-(CHO)₂C₉H₅}RuCpF were synthesized by the reaction of 1,3-diformylindenyl potassium with [CpRu(CH₃CN)₃][PF₆], [Cp*RuCl] _n , and [Cp^FRuCl] _n .     

Modified statistical theory of energy transfer in ion-molecule collisions

The modified statistical theory developed previously for potentials appropriate to interactions in neutral-neutral collisions, is now extended to more strongly attractive potentials involved in ion-neutral collisions. The model system is the collisional deactivation of C₅H₉⁺ by a variety of both polar and non-polar neutral molecules. A 12 - 6 - 4 potential is used for ion interaction with non-polar neutrals, and a 12 - 6 - 4 - 2 potential, as modified by Su and Bowers to take into account the rotational energy of the neutral, for interaction with polar neutrals. Calculated is (ΔE), the average energy lost by the ion in a collision, and compared with experiment. For C₅H₉⁺-CH₄ collisions, the calculated (ΔE) agrees with experiment within 5%. Predictions of the theory, namely that (ΔE) should increase with excitation energy and should decrease with the size of the excited reactant, are found to be in fair agreement with the somewhat ambiguous experimental evidence.     

Synthesis of π-(arene)metallocarboranes containing iron and ruthenium. Crystal structure of 3,1,2-(η6-1,3,5-(CH3)3C6H3)FeC2B9H11

The reaction of bis(arene)iron(II) salts (arene = mesitylene or hexamethylbenzene) or benzenedichlororuthenium(II) dimer with Tl[3,1,2-TlC₂B₉H₁₁] in THF produces neutral, air-stable π-(arene)(Fe, Ru)C₂B₉H₁₁ complexes in low or moderate yields. The metallocarboranes are formal analogues of [π-(arene)Fe, Ru)ⁿ⁺(C₅H₅)] species, and a single crystal X-ray structure of the title compound has established the closo sandwich geometry expected for the molecule on the basis of electron counting rules. The carborane cage was found to be disordered in the crystal but the essential features of the molecular geometry were not obscured. The mesitylene is symmetrically bound to the iron, and the Fe-arene (centroid) distance of 1.60 Å is similar to that found in the previously-characterized [(CH₃)₆C₆]Fe^I(C₅H₅) complex, despite the difference in the metal electronic configurations (d⁶ vs d⁷) and the change from the B₉C₂H₁₁^2? cage to C₅H₅^?. Crystals of 3,1,2-(η⁶-1,3,5-(CH₃)₃C₆H₃)FeC₂B₉H₁₁ are orthorhombic, space group Pn2₁a, with a = 12.638(4), b = 12.432(4), c = 9.686(3) Å.     

U¨bergangsmetall—Carbin—Komplexe: LXIV. Von equatorialen,zweikernigen silylcarben-komplexen des rheniumsU¨ber einen neuartigen kationischen silylcarbin-komplex zu axialen carben-komplexen

Decacarbonyldirhenium reacts with LiSi(C₆H₅)₃ to yield, on subsequent alkylation with FCH₃SO₃ or (C₂H₅)₃OBF₄, the equatorial nonacarbonyl[triphenylsily(alkoxy)carbene] dirhenium complexeseq-(CO)₉Re₂C(OR)Si(C₆H₅)₃(Ia, R - CH₃; Ib, R - C₄H₈OCH₃; Ic. R - C₂H₅). Reactions of these compounds with Al₂Cl₆ or Al₂Br₆ produce novel binuclear, cationic silycarbyne complexes, ax-[(CO)₉Re₂CSi(C₆H₅)₃]⁺ AlX₄^- (IIa, X - Cl; IIb, X - Br). Treatment of these complexes with alcohols results in formation of the axial nonacarbonyl(carbene)dirhenium complexesax-(CO)₉Re₂C(OR)Si(C₆H₅)₃ (IIIa, R - CH₃; IIIb, R - C₂H₅). The isomeric carbene complexes Ia and IIIa react with dialkylamine affording the isomeric aminocarbene complexeseq-(CO)₉Re₂C(CH₃)₂]-Si(C₆H₅)₃ (V) andax-(CO)₉Re₂Cl(NR₂)Si(C₆H₅)₃ (IVa, R - CH₃; IVb, R - C₂H₅). Reaction conditions, properties and spectroscopic data of the new compounds are reported.     

The synthesis of functional derivatives of the [1-CB9H10] anion by Brellochs reaction

Reactions of decaborane with various aldehydes in alkaline media were studied. The reactions with HCOH and 2-MeOC₆H₄CHO give the corresponding arachno-carboranes [6-R-arachno-CB₉H₁₃]⁻ (R = H, C₆H₄-2-OMe), whereas the reactions with C₆H₅CHO, 4-BrC₆H₄CHO, 4-MeCONHC₆H₄CHO, and 2-SC₄H₃CHO result in the nido-carboranes [6-R-nido-CB₉H₁₁]⁻ (R = C₆H₅, C₆H₄-4-Br, C₆H₄-4-NHCOMe, 2-SC₄H₃). Both the arachno- and nido-carboranes can be easily oxidized with elemental iodine in an alkaline aqueous solution giving the corresponding closo-derivatives [2-R-closo-2-CB₉H₉]⁻. These closo-2-isomers, under heating in solution, undergo rearrangement to more thermodynamically favorable closo-1-isomers [1-R-closo-1-CB₉H₉]⁻. The structure of (Bu₄N)[1-(4-BrC₆H₄)-1-CB₉H₉] was determined using single crystal X-ray diffraction.     

Reduction of (1,3-diformylindenyl)cyclopentadienylruthenium derivatives

The reduction of the (1,3-diformylindenyl)cyclopentadienylruthenium derivatives {η⁵-1,3-(CHO)₂C₉H₅}RuCp (Cp = C₅H₅), {η⁵-1,3-(CHO)₂C₉H₅}RuCp* (Cp* = C₅Me₅), and {η⁵-1,3-(CHO)₂C₉H₅}RuCpF (Cp^F = C₅Me₄CF₃) with NaBH₄ or LiAlH₄ under mild conditions affords the [1,3-bis(hydroxymethyl)indenyl]cyclopentadienylruthenium complexes {η⁵-1,3-(CH₂OH)₂C₉H₅}RuCp, {η⁵-1,3-(CH₂OH)₂C₉H₅}RuCp*, and {η⁵-1,3-(CH₂OH)₂C₉H₅}-RuCp^F, respectively, in good yields.     

Synthesis of the compounds [Re(CR)(CO)2(η5-C9H7)][BF4] (R = C6H4Me-4 or C6H3Me2-2,6) and the preparation of complexes with FeRe bonds

The salts [Re(CR)CO)₂(η⁵-C₉H₇)][BF₄] [R = C₆H₄Me-4 or C₆H₃Me-2,6; η⁵- C₉H₇ = indenyl] have been prepared and used to synthesize the dimetal compounds [FeRe(μ-CR)(μ-NO)(CO)₄(η⁵-C₉H₇)]. The iron-rhenium species containing a bridging p- tolylmethylidyne ligands react with [Fe₂(CO)₉] or with [Ru(CO)₄(η-C₂H₄)], respectively, to yield the trimetal compounds ([FeMRe(μ₃-CC₆H₄Me-4)(μ-CO)(μ-NO)(CO)₆(η ₅-C₉H₇)] (M = Fe or Ru).     

(Liquid + liquid) equilibrium in binary systems of isomeric C8 aliphatic monoethers with acetonitrile and its interpretation by the COSMO-SAC model

The (liquid + liquid) solubility curves have been determined by a synthetic method for six binary mixtures of [acetonitrile + {heptyl methyl ether CH₃OⁿC₇H₁₅, or ethyl hexyl ether C₂H₅OⁿC₆H₁₃, or pentyl propyl ether ⁿC₃H₇OⁿC₅H₁₁, or isopentyl propyl ether ⁿC₃H₇Oⁱ C₅H₁₁, or dibutyl ether ⁿC₄H₉OⁿC₄H₉, or butyl isobutyl ether ⁿC₄H₉OⁱC₄H₉}]. The possibility of the COSMO-SAC model to account for the thermodynamic differences between these systems has been tested and the discussion on the influence of screening charge of ethers on the system properties was undertaken.     

Synthesis and reactivity of 2-(tert-butylcyclopentadienyl)-indenyl dinuclear ruthenium complex [η5:η5-(tBuC5H3)(C9H6)]Ru2(CO)4: Halogen induced Ru cleavage from indenyl ring

Thermal reaction of Ru₃(CO)₁₂ with unsymmetrical Fv ligand 2-(tert-butylcyclopentadienyl)-indene provided [η⁵:η⁵-(^tBuC₅H₃)(C₉H₆)]Ru₂(CO)₄ (2) in good yield. When 2 reacted with three or more equivalent of halogen X₂, compounds [(η⁵-^tBuC₅H₃)(C₉H₆X)]Ru(CO)₂X (X = Br, 3; I, 4) were isolated in moderate yield. In complexes 3 and 4 only the Cp rings were coordinated with Ru(CO)₂X, along with uncomplexed halogenated-indenyl rings. All the new complexes have been fully characterized. X-ray characterization of 2, 3, and 4 are also provided.     

Intramolekulare Diels-Alder-Additionen in 6-(But-3-enyl)-6-methyl-cyclohexa-2,4-dien-1-on-Systemen; eine neue Synthese von Twistanderivaten

Alkylation of the sodium salt of mesitol with 2-bromomethyl-buta-1,3-diene ( 7 ) in benzene and subsequent refluxing of the reaction mixture gave 7% 2-methylene-3-butenyl-mesitylether ( 8 ), 12% 5-methylene-1,3,8-trimethyl-tricyclo[4,3,1,0^3,7]-8-decen-2-one ( 9 ) and 44% 9-methylene-1,3,5-trimethyl-tricyclo[4,4,0,0^3,8]-4-decen-2-one ( 10 ), a twistane derivative. The same procedure, when applied to the sodium salt of 2,6-dimethyl-4-methoxyphenol, gave in 73% yield a 26:18:54 mixture of 2,6-dimethyl-4-methoxyphenyl-(2-methylene-3-butenyl)-ether ( 11 ), 1,3-dimethyl-8-methoxy-5-methylene-tricyclo[4,3,1,0^{3, 7}]-8-decen-2-one ( 12 ), and 1,3-dimethyl-5-methoxy-9-methylene-tricyclo[4,4,0,0^{3, 8}]-4-decen-2-one ( 13 ). The tricyclic ketones 9 and 10 , or 12 and 13 , were also obtained on heating 8 or 11 respectively at 176° in decane solution. Alkylation of the sodium salt of 2,6-dimethylphenol with 3-butenylbromide in boiling toluene gave 1,3-dimethyl-tricyclo[4,3,1,0^3,7]-8-decen-2-one ( 17 ) as the only tricyclic product in 8% yield. The structures of the twistane derivatives 10 and 13 as well as those of the ketones 9, 12 and 17 were mainly deduced from spectroscopic data. Furthermore, the ketones 10 and 13 could be converted to the twistane derivatives 20 and 22 , possessing C₂-symmetry. On the other hand, compounds 9 and 17 gave only the asymmetric derivatives 18 and 21 .     

Studies on Taxol biosynthesis: preparation of taxadiene-diol and triol derivatives by deoxygenation of taxusin

The putative Taxol biosynthesis metabolites, taxa-4(20),11(12)-diene-5α,13α-diol (7), taxa-4(20),11(12)-diene-5α,9α,13α-triol (9), and taxa-4(20),11(12)-diene-5α,10β,13α-triol (10), have been prepared by Barton deoxygenation of the C-9 and C10-hydroxyl groups of protected derivatives of taxusin, a major taxoid metabolite isolated from Yew heart wood. The synthetic protocol devised is amenable for the preparation of isotopically labeled congeners that will be useful to probe further intermediate steps in the biosynthesis of Taxol.     

Preparation of chelate bis(imine)nickel allyl systems by reaction of their corresponding butadiene complexes with electrophiles

The chelate 1,2-bis(imine)nickel(butadiene) complex 4a (chelate ligand derived from condensation of biacetyl with 2,6-diisopropylaniline) adds the strong Lewis acid B(C₆F₅)₃ at the terminal carbon atom of the butadiene ligand to yield the dipolar substituted π-allyl-type betaine complex (lig)Ni[η³-C₃H₄-CH₂B(C₆F₅)₃] (Z-6a). At 90 °C the kinetically formed product equilibrated with its E-6a isomer. Similarly, 4a adds the boron Lewis acid (pyrrolyl)B(C₆F₅)₂ to yield the corresponding neutral dipolar π-allyl betaine complex Z-7a, that slowly equilibrated with E-7a over several hours at ambient temperature. Protonation of the butadiene ligand of complex 4a was achieved by treatment with the neutral Brønsted acid (2H-pyrrol)B(C₆F₅)₃ to yield the [(lig)Ni(η³-crotyl)⁺][(pyrrolyl)B(C₆F₅)₃⁻] salt 9a (Z-/E-9a ratio=90:10 upon preparation). At 298 K this salt rearranged to a 5:95 mixture of Z-9a/E-9a with a Gibbs activation energy of ΔG^‡ (298 K)=22.3±0.2 kcal mol⁻¹. Complex 4a added [Ph₃C⁺] to the butadiene ligand to yield the salt [(lig)Ni(η³-C₃H₄-CH₂CPh₃)⁺][B(C₆F₅)₄⁻] (Z-12a), that proved isomerically stable under the applied reaction conditions. Similar reactions were carried out starting from the acenaphthylene 1,2-dione derived chelate bis(imine)Ni(butadiene) complex 4b. The systems 6, 7, 9 and 12 were found to be active ethene polymerization catalysts in the presence of Al(i-Bu)₃.     

Phendione and anisylhydroresorcinol in the synthesis of 1,7-phenanthroline derivatives

Condensation of 5-phenyl-1,3-cyclohexanedione and 5-(p-methoxyphenyl)-1,3-cyclohexanedione with 5-quinolylamine and aldehydes of aromatic, heteroaromatic, and cyclohexene series provided new 7-aryl(heteryl, cyclohexenyl)-10-phenyl- or (p-methoxyphenyl)-7,10,11,12-tetrahydro-9H-benzo[b][1,7]phenanthrolin-8-ones containing two asymmetrical atoms C⁷ and C¹⁰. ¹H NMR spectroscopy revealed the presence of diastereomers in the target reaction products.     

Molecular structure of 5-[(triphenyl-phosphoranylidene)hydrazono]-exo-3-azatricyclo[5.2.1.02.6]decane-4-one

The molecular structure of 5-[(triphenylphosphoranylidene)hydrazono]-exo-3-azatricyclo[5.2.1.0^2.6]decane-4-one is determined. The C₂₇H₂₆N₃OP compound crystallizes in the space group P?1: a = 9.2163(9) Å, b = 11.1102(11) Å, c = 11.9397(12) Å, α = 74.284(2)°, β = 78.532(2)°, γ = 72.004(2)°.     

Arene substitution by iridium complexes under mild conditions

[(C₅Me₅Ir)₂Cl₄] reacts with Al₂Me₆ in saturated hydrocarbons to give [C₅Me₅IrMe₄) or cis- and trans-[C₅Me₅Ir)₂Me₂(α-CH₂)₂], depending on workup conditions. In benzene or toluene solution the main product is [(C₅Me₅Ir)₂Me(Aryl)(α-CH₂)₂] (aryl = Ph or m- plus p-tolyl, ratio 2/1); if CO is introduced into the benzene solution the products are [C₅Me₅Ir(CO)R¹R²] (R¹ = Me, R² = Ph; R¹ = R² = Me or Ph).     

Diorgano-gallium and -indium complexes with N-heterocyclic carboxylic acids: Synthesis, characterization and structures of [Me2M(O2C-C5H4N)]2, M = Ga or In

The reaction of triorgano-gallium and -indium etherate with heterocyclic carboxylic acids in benzene at room temperature yields complexes of the type [R₂M(L)]_n(M = Ga or In; R = Me or Et; L = 2-(C₅H₄N)CO₂, 2-(C₄H₃N₂)CO₂ or 2-(C₉H₆N)CO₂). These complexes have been characterized by elemental analysis, IR, UV-vis, NMR (¹H and ¹³C{¹H}) and mass spectral data. Complexes with L = (C₅H₄N)CO₂- and (C₉H₆N)CO₂- showed photoluminescence on excitation with ∼250 or ∼310 nm radiation, respectively. Single crystal X-ray structural analysis of [Me₂M(O₂C-C₅H₄N-2)]₂ (M = Ga or In), revealed a dimeric structure with five-coordinate metal atoms arising from the presence of two tridentate bridging picolinate ligands.     

Chemistry of strained polycyclic compounds—V : The stereospecific cationic cage expansion reaction of 4-homocubane carbinols to 1,3-bishomocubane bridgehead alcohols

The cationic rearrangement of four homocubane bridgehead carbinols viz dimethyl 4-(1-bromopentacyclo[4.3.0.0^2,5.0^3,8.0^4,7]nonyl-9-one ethylene ketal) carbinol 2, diphenyl 4-(1-bromopentacyclo[4.3.0.0^2,5.0^3,8.0^4,7]nonyl-9-one ethylene ketal) carbinol 3, 4-(1-bromopentacyclo[4.3.0.0^2,5.0^3,8.0^4,7] nonyl-9-one ethylene ketal) carbinol 4 and 4-(1-bromopentacyclo[4.3.0.0^2,5.0^3,8.0^4,7]nonyl) carbinol 16, has been studied undervarious conditions.Exclusive migration of the C₄C₇ (or the equivalent C₃C₄ bond) in the homocubane skeleton was observed leading to 1,3-bishomocubane bridgehead alcohols. Relief of cage constraint governs the selective course of these cage expansions.     

Structure of arsenic 8-mercaptoquinolinate: Synthesis and crystal structure of arsenic 4-methoxy-8-mercaptoquinolinate As[C<Subscript>9</Subscript>H<Subscript>5</Subscript>(OCH<Subscript>3</Subscript>)NS]<Subscript>3</Subscript>

Arsenic 4-methoxy-8-mercaptoquinolinate As[C₉H₅(4-OCH₃)NS]₃ (I) was synthesized and studied by X-ray diffraction. Crystals are trigonal: space group R3, a = b = 13.9867(4) Å, c = 12.4991(5) Å, γ = 120°, V = 2117.58(12) ų, ρ = 1.519 g/cm³, Z = 3. An arsenic atom in the crystal structure occupies a special position on axis 3. The structural unit of the crystal (neutral complex I) has symmetry C3. 4-Methoxy-8-mercaptoquinoline acts as a bidentate (N,S-) ligand. The coordination polyhedron of the arsenic atom is a symmetric octahedron (3S + 3N) or, with allowance for the lone electron pair, ψ-one-capped octahedron (3S + 3N + E). Bond lengths are as follows: As-S, 2.3179(7)Å; As…N 2.688(3) Å. The geometries of coordination polyhedra of arsenic atoms are compared in the crystal structures of As(C₉H₆NS)₃, As[C₉H₅(2-CH₃)NS]₃, and As[C₉H₅(4-CH₃)NS]₃.