Synthesis of the grapevine moth sex pheromone by Grignard—Schlosser cross-coupling: The effect of the electrophile structure on the stereoisomeric ratio in the reaction products

1-Acetoxy-2E,4Z-heptadiene (4) and 1-bromo-3E,5Z-octadiene (5) were obtained with 90 and 88–92 % configurational purity, respectively, starting from 2,4-heptadiyn-1-ol or 3,5-octadiyn-1-ol. The Li₂CuCl₄-catalyzed cross-coupling of the allylic acetate4 with 5tert-butoxypentylmagnesium chloride affords 1-tert-butoxy-7E,9Z-dodecadiene (11) contaminated with 25 % of minor stereoisomers in 54–60 % overall yield. Under similar conditions, the homoallylic bromide5 reacts with 4-tert-butoxybutylmagnesium chloride to give in 50–52 % yield another sample of diene11 containing 17 % of minor stereoisomers. If the latter coupling is carried out with enyne8 instead of5 followed bycis-hydrogenation of the triple bond in the resulting product, the configurational purity of diene11 is as high as 84.7 % (45 % overall yield). The reaction of11 with Ac₂O in the presence of FeCl₃ leads directly to the target 7E,9Z-dodecadienyl acetate (1) with somewhat lower configurational purity than that of the starting ether11.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1133–1137, June, 1993.     

Heterogeneous catalytic synthesis and structure of 5,5a,10a,11-tetrahydro-10H-indeno[1,2-b]quinoline

Hydrogenation of 10H-indeno[1,2-b]quinoline in benzene in the presence of R₂S₇ gave 5,5a,10a,11-tetrahydro-10H-indeno[1,2-b]quinoline, the structure of which was established by mass-, IR, UV,¹³C, and¹H NMR spectra. Thecis fusion of the indan and tetrahydroquinoline fragments, the axial orientation of the proton at C(5a), and the equatorial orientation of the proton at C(10a) were confirmed by molecular mechanics calculations using the PC MODEL program.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1098–1101, June, 1994.     

Hydrogenation of α-methylstyrene on membrane catalysts

Conclusions The hydrogenation of -methylstyrene on Pd-Ru and Pd-Ni membrane catalysts is zero-order relative to the starting substrate and close to 0.5 relative to H₂. The use of the Pd-Ru catalyst is recommended for the hydrogenation of -methylstyrene. Hydrogenation on this catalyst is superior in its mechanical strength to the Pd catalyst.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1158–1160, May, 1988.     

Synthesis of Drim-9(11)-en-8α- and -8β-ols from Drimenol

Drim-9(11)-en-8α-ol and drim-9(11)-en-8β-ol were synthesized in six steps from drimenol. Drimenol was oxidized by P₂O₅ and DMSO to drimenal, which isomerized with p-TsOH into isodrimenal. Isodrimenal was reduced by NaBH₄ into isodrimenol, epoxidation of which by m-CPBA gave a mixture (3.4:1) of α- and β-epoxyisodrimenols. These reacted with tosyl chloride in Py to give a mixture of α- and β-epoxyisodrimenol tosylates. Treatment of the tosylate mixture with KI and then Ph₃P produced a mixture of drim-9(11)-en-8α- and -8β-ols that was separated chromatographically. The overall yield was ∼26%.__________Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 152–155, March–April, 2005.     

Solvolysis of allylic prostaglandin mesylates: moderate 1,3-<Emphasis Type="Italic">syn</Emphasis>-stereoselectivity

The stereochemistry of S _N2 and S _N2 substitutions of the allylic mesyloxy group in mesylates of prostaglandin allylic epimeric 13- and 15-alcohols under the action of various nucleophiles (H₂O, MeOH, AcOH, LiBr) was studied. The substitution accompanied by rearrangement occurs with moderate (1.4–1.6 : 1) syn-stereoselectivity with respect to the configuration of the mesyloxy group, which increases with decreasing temperature and depends only slightly on the nature of the nucleophile.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2510–2518, November, 2004.     

Stereoselective hydrogenation of 2-hexyne on Cu/γ-Al2O3 catalysts

The stereoselective hydrogenation of 2-hexyne in ethanol on Cu/-Al₂O₃ catalysts (1–40 % Cu) at 4–10 atm and 80–120 °C has been studied. The reaction affordscis-2-hexene as the only reaction product in 100 % yield at [Cu] 30 %. For samples with 20 % Cu, hydrogenation proceeds in parallel with absorption of H₂ by the catalyst.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1314–1315, July, 1993.     

Synthesis ofS-(+)-methoprene

An optically active juvenile hormone analogue,S-(+)-methoprene (1), is synthesized in six steps from technical gradeS-(+)-3,7-dimethyl-1,6-octadiene ((+)-dihydromyrcene, e.e. –50%) by a novel procedure which begins with selective hydroalumination-oxidation to giveS-(-)-citronellol. This alcohol is oxidized to giveS-(-)-citronellal which on reaction with allylmagnesium chloride affords 6S, 10-dimethyl-1,9-undecadien-4 R/S-ol (5). Smidt-Moiseev oxygenation of 5 followed by dehydration leads to 6S, 10-dimethyl-3E,9-undecadien-2-one. The latter on treatment with isopropoxyethynylmagnesium bromide is transformed into isopropyl 3,7S,11-trimethyl-2E/Z,4,E,10-dodecatrienoate which upon Brown solvomercurationreduction in MeOH gives1 in 14% overall yield.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 108–109, January, 1993.     

Two-Dimensional Supramolecular from the Self-Assembly of Dissymmetrical Oxamidato-Bridged Heterometallic Trinuclear Building Blocks: Synthesis, Crystal Structure, and Magnetic Properties

Two heterometallic trinuclear complexes {[Cu(oxbp)]₂Co(H₂O)₂}1.5DMF0.5H₂O (complex 1) and {[Cu(oxbm)]₂Co(H₂O)₂}2DMF (complex 2) were obtained from the self-organization of two new dissymmetrical oxamidato-bridged copper(II) building blocks [Cu(oxbp)]^– and [Cu(oxbm)]^–[H₃oxbp=N-benzoato-N'-(3-aminopropyl)oxamido, H₃oxbm=N-benzoato-N'-(2-amino-2-methylethyl)oxamido, DMF=dimethylformamide]. The crystal structure of complex 1 has been determined. Complex 1 crystallize in triclinic system, space group P-1, a=8.0609(16) Å, b=10.661(2) Å, c=22.279(5) Å, =85.32(3), =86.64(3), =70.90(3), and Z=1. The crystal structure of complex 1 consists of neutral trinuclear complex units, and hydrogen bond involved DMF and water molecules. Through the hydrogen bonds, weak coordination and CuCu weak interactions, complex 1 features a 2-D supramolecular structure. Magnetic susceptibility measurements (5–100 K) indicate that the central Co(II) and terminal copper metal ions are antiferromagnetically coupled with J=–28.09 and J=–29.70 cm^–1 for complex 1 and 2, respectively.     

The properties of supported rhenium catalysts in the dehydrogenation of cyclohexane

The 2 % Re/sibunite catalyst is more active than 2 % Re/-Al₂O₃ and 2 % Re/-Al₂O₃ catalysts in the dehydrogenation of cyclohexane into benzene (T = 350 °C,w = 0.5 h–1). The substitution of NH₄ReO₄ by HReO₄ in the preparation of the catalyst enhances its activity by a factor of 1.3. Treatment with HNO₃ or oxalic acid increases the selectivity by a factor of 1.2 and 1.35, respectively, the overall conversion of cyclohexane being 32–40 %.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 2119–2121, August, 1996.     

The Stability of Monolith CuZSM-5 Catalysts for the Selective Reduction of Nitrogen Oxides with Hydrocarbons: II. Synthesis and Characterization of Bulk Cu(80% ZSM-5 + 20% Al2O3) Catalysts

The effects of ion-exchange conditions and the zeolite Si/Al atomic ratio on the copper contents of Cu(80% ZSM-5 + 20%Al₂O₃) catalysts and on the catalytic activity in the selective reduction of NO with propane were studied. It was found that the synthesis of these catalysts exhibited the same behavior as in the case of bulk CuZSM-5 catalysts containing no Al₂O₃. The copper contents of the catalysts depend on the pH and concentration of copper solutions used for ion exchange, and the maximum activity (NO conversion) is attained even at an exchange level (Cu/Al) close to 100% regardless of pH and the zeolite Si/Al atomic ratio. At 300–400°C, the activity of the test catalysts is 10–20% lower than the activity of CuZSM-5 catalysts containing no Al₂O₃at equal exchange levels. This difference in the activity almost disappeared as the reaction temperature was increased. It was also found that in the Cu(80% ZSM-5 + 20%Al₂O₃) catalysts, an exchange level close to that in CuZSM-5 catalysts is attained by ion exchange from more concentrated solutions. An increase in the exchange level to 100% (by an increase in the pH of a copper solution from 6 to 10, as in the case of CuZSM-5 catalysts), had no effect on the activity.     

Arylation of aliphatic alcohols with tri-p-tolylbismuth and tri-p-tolylbismuth diacetate in the presence of a copper salt

Tri-p-tolylbismuth diacetate in the presence of a catalytic amount of a copper(II) salt (10.02, mol/mol) and tri-p-tolylbismuth in the presence of copper diacetate (1 2) replace the hydrogen atom of the hydroxyl groups of methanol and butanol with a tolyl group at 80 °C in up to 90 % yields.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 156–158, January, 1995.     

Linear scan stripping voltammetry of copper(II) at the chemically modified carbon paste electrode

A new chemically modified electrode (CME), -benzoinoxime (CUPRON) modified carbon paste electrode, for determining copper(II) is reported because of its excellent selectivity and sensitivity. The electrode is made by mixing a quantity of CUPRON (25%, w/w) with graphite powder (50%, w/w) and paraffin oil (25%, w/w). The CME preferentially deposits copper from the pH 8.5 NH₃-NH₄Cl buffer solution containing copper(II) under an open circuit and most of metal ions do not interfere with the measurements. The detection limit (S/N of three) for determining Cu(II) is 3 × 10^–10 g/ml after 10 min accumulation in fast linear scan stripping voltammetric measurement. Linear calibration curves are obtained for Cu(II) concentration ranged from 1 × 10^–8 M to 1 × 10^–6 M. The response can be maintained with relative standard deviation of 6.0% in a 5 × 10^–6 M Cu(II) solution after eight accumulation/measurement/ regeneration cycles at the same electrode surface. The effect resulted from carbon paste preparation, reduction potential, electrode renewal, electrolyte and solution pH, preconcentration time, concentration dependence, possible interference and other variables has been evaluated. As for application, the CME demonstrates its high sensitivity and copper-selectivity in complex composition samples, such as anodic mud and polluted water.     

Selective alkylation of xylenes by alcohols on zeolite catalysts

The peculiarities of catalytic performance of crystalline aluminosilicates of different types and compositions (X, Y including dealuminated Y, mordenite, pentasil ZSM-5), as well as of amorphous aluminosilicate catalyst in conversion of xylene + alcohol mixtures were studied. New data were obtained for alkylation ofo-xylene withtert-butyl alcohol, concerning controlling the selectivity and stability of the zeolite catalysts in reactions proceeding with the participation of water, including the water evolved during the reaction, in particular by controlling the acidic properties and hydrophobycity of the zeolites. A catalyst ensuring production of 1,2-dimethyl-4-tert-butylbenzene (DMTBB) with a 94% yield and selectivity of alcohol conversion to the target product of 94–97% was developed. The catalyst can be used as the basis for a high-performance and environmentally safe method for the synthesis of DMTBB. The catalysts developed can be also used for selective alkylation ofo-xylene by C₃-C₅ alcohols and for alkylation ofm-xylene bytert-butyl alcohol.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No, 12, pp, 2912–2917, December, 1996.     

ESR study of weak exchange interactions in binuclear copper(ii) complexes with acyldihydrazones of fluorinated β-diketones

A series of binuclear copper(ii) complexes with acyldihydrazones of aliphatic dicarboxylic acids (from malonic to adipic) and fluorinated -diketones (trifluoro- and hexafluoroacetylacetone) of composition Cu₂L·2Py (H₄L is acyldihydrazone) were studied by ESR spectroscopy. The ESR spectra of solutions of complexes with trifluoroacetylacetone acyldihydrazones have an isotropic signal with a seven-line hyperfine structure from two equivalent copper nuclei (g = 2.112, a _Cu = (39—40)·10^–4 cm^–1), which is indicative of weak exchange interactions between the paramagnetic centers due to spin density delocalization through a chain of the -bonds of the polymethylene bridge. On going to hexafluoroacetylacetone derivatives, the coupling is suppressed and the ESR spectra of solutions of such complexes show a signal with a four-line hyperfine structure (g = 2.121—2.131, a _Cu = (55—63)·10^–4 cm^–1) typical of mononuclear copper complexes.     

Disposition of copper(II) inβ-cyclodextrin

Distances of glucose protons in-cyclodextrin (BCD) from copper(II) in copper(II)--cyclodextrin have been determined from¹H NMR spin-lattice relaxation time (T ₁) measurements for the first time. Very lowT _1p /T _2p values indicated the dipolar mechanism to be the most dominant one in determining the paramagnetic contribution to relaxation. The distances of copper(II) from BCD glucose protons indicated copper(II) to be present almost in the centre, inside the cavity in the same plane as H-1 and H-4. An average distance of about 5.0–5.9 Å was obtained for copper(II) from the H-2, H-3, H-1, H-4 and H-6 a and b protons in BCD.     

Interaction of fluorine-containing 1,3-dicarbonyl compounds with polyamines

In the reaction of fluorinated copper(II) 1,3-diketonates with diethylenetriamine (or triethylenetetramine) in CHCl₃, N,N-bis(1,3-aminovinylketones) are formed in 21–35% yields. Fluorine-containing 1,3-diketones and 1,3-ketoesters, upon interaction with polyamines without solvent, undergo acid cleavage, forming the corresponding amides. The copper(II) 1,3-ketoesterates are readily cleaved in CHCl₃ at 25°C in excess triethylenetetramine or ethylenediamine.Department of Fine Organic Synthesis, Institute of Organic Chemistry, Ural Branch, Russian Academy of Sciences, 620219 Ekaterinburg. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 11, pp. 2591–2596, November, 1992.     

A calorimetric study ofN,N-dimethylformamide complexes of copper(II) in acetonitrile

Complex formation of copper(II) with N,N-dimethylformamide(DMF) has been investigated calorimetrically in acetonitrile at 25°C. Calorimetric titration curves obtained are explained in terms of formation of [Cu(dmf) _n ]²⁺ (n=1–4, 6) and their formation constants, enthalpies and entropies were determined. Formation of [Cu(dmf)₅]²⁺ is uncertain. The stepwise enthalpies S ₃ ⁰ and entropies S _n ⁰ at each consecutive step are all negative except for S ₃ ⁰ . The overall enthalpies of formation of [Cu(dmf)₆]²⁺ is –(77.8±5.4) kJ-mol^–1, which is compared with the enthalpy of transfer of copper(II) ion, H _t ^o =–79.7 kJ-mol^–1, from acetonitrile to DMF.     

Osmium liquid-phase catalysts for hydrogenolysis of saturated hydrocarbons and hydrogenation of arenes

Reduction of OsO₄ by molecular hydrogen in alkane (cycloalkane) or benzene (toluene) solution produces small-ligand clusters of osmium of composition Os_1.5–2.5. CH_0–2 with a particle size 10–40 Å and a specific surface area of 34–46 m²/g. Hydrogenation of dry catalyst produces methane. The small-ligand osmium clusters obtained effectively catalyze hydrogenolysis of alkanes and cycloalkanes at 100–150°C and =5 MPa and hydrogenation of benzene at 20°C and =0.1 MPa.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2428–2433, November, 1989.     

Determination of copper(I)-ethylene complexes, [Cu(C2H4)]+ and [Cu(C2H4)2]+, with aid of EDTA titration of copper(I) and copper(II) ions

Summary Volumetric measurements of ethylene and simple EDTA titration of copper(I) and copper(II) ions confirm that [CuL]⁺ and [CuL₂]⁺ are formed when an aqueous solution of copper(II) is reduced by copper metal in the presence of ethylene, (L). The formation constants,K ₁=[CuL⁺]²[Cu²⁺]^–1[L]^–2 andK ₂=[CuL ₂ ⁺ ]^–1[L]^–1, have been estimated. The formation of [CuL]⁺ is accompanied by an enthalpy change, H, of –25 kJ mol^–1, and a positive entropy change, S, of 13 J mol^–1 K^–1.     

Methylpyrazine Ammoxidation over Binary Oxide Systems: V. Effect of Phosphorus Additives on the Physicochemical and Catalytic Properties of a Vanadium–Titanium Catalyst in Methylpyrazine Ammoxidation

Oxide vanadium–titanium catalysts modified by phosphorus additives (20V₂O₅–(80 –n)TiO₂–nP₂O₅, n = 1, 3, 5, 10, and 15 wt %) are studied in methylpyrazine ammoxidation. Two regions of compositions are found corresponding to radically different catalytic properties, namely, catalysts with a low (5 wt % P₂O₅) and high (10 wt % P₂O₅) concentration of the additive. In the first case, the introduction of phosphorus is accompanied by a gradual increase in the activity. In the second case, an increase in the additive concentration results in a decrease in the activity and selectivity to the target product, pyrazineamide, and a simultaneous increase in the selectivities to by-products, pyrazine and carbon oxides. The catalysts are characterized by X-ray diffraction analysis, differential dissolution, IR, and NMR spectroscopic data. As in the binary system, the active sites of the samples with a low concentration of phosphorus contain V⁵⁺ cations in a strongly distorted octahedral oxygen environment, which are strongly bound to a support due to the formation of V–O–Ti bonds. The catalytic properties of the samples containing 10 wt % P₂O₅ are due to the presence of the phase of a triple V–P–Ti compound with an atomic ratio V : P : Ti approximately equal to 1 : 1 : 1. The V⁵⁺ cations in this compound occur in a weakly distorted tetrahedral oxygen environment and are bound to the tetrahedral P⁵⁺ cations.