An efficient heterogeneous catalytic system for chemoselective hydrogenation of unsaturated ketones in aqueous medium

A highly chemoselective and green heterogeneous catalytic system of immobilized Ru(II)–phenanthroline complexes on amino functionalised MCM-41 material for the chemoselective hydrogenation of unsaturated ketones to unsaturated alcohols is demonstrated using water as a solvent. The XRD and FTIR spectra show the highly ordered hexagonal nature of the MCM-41, even after encapsulation of the ruthenium complex. The complex retains its configuration after anchoring, as was confirmed by FTIR and UV–Vis analysis. The detailed reaction parametric effect was studied for the hydrogenation of 3-methylpent-3-en-2-one to achieve complete conversion up to >99% chemoselectivity of 3-methylpent-3-en-2-ol. The anchored heterogeneous catalysts were recycled effectively and reused five times with marginal changes in activity and selectivity. The use of water as a solvent not only afforded high activity for the hydrogenation reaction compared to organic solvents, but also afforded a green process.     

Synthesis and Chemical Transformations of 5-Alkyl(phenyl)-4,5,6,7-tetrahydro[1,2,4]triazolo[1,5-<Emphasis Type="Italic">a</Emphasis>]pyrimidin-7-oles

5,5,7-Trimethyl-4,5,6,7-tetrahydro[1,2,4]triazolo[1,5-a]pyrimidin-7-ol was synthesized by cyclocondensation of 3-amino-1,2,4-triazole with 4-methylpent-3-en-2-one; its chemical transformations, and also the transformations of 5-phenyl-4,5,6,7-tetrahydro[1,2,4]triazolo[1,5-a]pyrimidin-7-ol were investigated in reactions with reagents of diverse electronic nature.     

Spectrophotometric behaviour of quinolinium oxime-palladium(II) complexes

Summary It has been established that 1-(2-phenyl-2-hydroxyiminoethyl)-1-quinolinium chloride, 1-(2-phenyl-2-hydroxyiminoethyl)-1-isoqui-nolinium chloride, 1-(2-phenyl-2-hydroxyiminoethyl)-1-(4-methyl)-quinolinium chloride and 1-(2-phenyl-2-hydroxyiminoethyl)-1-(6-methyl)quinolinium chloride react with palladium(II) chloride in the pH range 3.3–7.1 and form yellow water-soluble 11 complexes with maximum absorbance at 413 nm. The conditional stability constants of the complexes at the optimum pH of 6.5 are all about 10^4.7, and the molar absorptivities are in the range 2.2–2.6×10³ l·l mole^–1·cm^–1 at pH 6.5 and 413 nm. Beer's law is obeyed up to 3–4×10^–4 M oxime concentration, depending on the oxime determined.     

Boron chelates with 5,5,5-trifluoro- and 5,5,5-trichloro-4-aminopent-3-en-2-ones

Boron chelates were obtained by the reaction of butoxy(butylthio)diphenylborane with 5,5,5-trifluoro(trichloro)-4-aminopent-3-en-2-one, and their reactions with primary amines were investigated. -Diiminate complexes of boron with trifluoro- and trichloromethyl groups were synthesized.N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117913 Moscow. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 11, pp. 2657–2661, November, 1992.     

Catalytic peoperties of palladium. Fixed on poly(m- and p-) hydroxyphenylbenzoxazole-terephthalamides

Conclusion Polymeric chelates of palladium with poly(m- and p-)hydroxyphenylbenzoxazoleterephthalamides as fibers exhibit catalytic activity in the hydrogenation of monoolefins and dienes.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1420–1421, June, 1982.     

Azolyl-substituted 1,2,3-triazoles

Huisgen reaction of (E)-1,5-diarylpent-2-en-4-yn-1-ones and (E)-1,5-diarylpent-1-en-4-yn-3-ones afforded 1-aryl-3-(5-aryl-1H-1,2,3-triazol-4-yl)prop-2-en-1-ones and 3-aryl-1-(5-aryl-1H-1,2,3-triazol-4-yl)-prop-2-en-1-ones, respectively. (E)-1-Aryl-3-(5-phenyl-1H-1,2,3-triazol-4-yl)prop-2-en-1-ones reacted with hydrazine hydrate and phenylhydrazine to give 72–93% of 4-(3-aryl-4,5-dihydro-1H-pyrazol-5-yl)-5-phenyl-1H-1,2,3-triazoles which underwent dehydrogenation on heating in boiling acetic acid with formation of the corresponding pyrazole derivatives. The molecular structures of (E)-3-phenyl-1-(5-phenyl-1H-1,2,3-triazol-4-yl)prop-2-en-1-one and 4-[3-(4-methylphenyl)-1-phenyl-4,5-dihydro-1H-pyrazol-5-yl]-5-phenyl-1H-1,2,3-triazole were studied by X-ray analysis. 4-(3-Aryl-4,5-dihydro-1H-pyrazol-5-yl)-5-phenyl-1H-1,2,3-triazoles showed toxicity against Daphnia magna.     

Hydrogenation of difurfurylideneacetone on a raney nickel catalyst

1.5-Difurylpent-1-en-3-one, 1,5-difurylpentan-3-one, 1,5-ditetrahydrofurylpentan3-one, and l,5-ditetrahydrofuryl-pentan-3-ol were obtained by hydrogenation of difurfuryldieneacetone on a Raney nickel catalyst at 20–65°C and atmospheric pressure. It was established that the hydrogenation of difurfuryldieneacetone is a zero-order reaction with respect to the concentration of the starting compound. The rate constants of the reaction were found; the activation energy found for 20–65°C is 6.2±0.5 kcal/mole.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 462–465, April, 1979.     

Simultaneous determination of DTPA,EDTA, and NTA by UV–visible spectrometry and HPLC

In this study, UV–visible spectrophotometry (UV–Vis) and high-performance liquid chromatography (HPLC) were used for simultaneous analysis of chelating agents diethylenetriamine pentaacetic acid (DTPA), ethylenediamine tetraacetic acid (EDTA), and nitrilotriacetic acid (NTA), as their metal chelates in dishwashing detergents, natural waters, and pulp mill water. The total amounts of the chelating agents in dishwashing detergents were verified by potentiometric titration with Fe(III) solution. Nickel(II) chelates were determined by UV–Vis and iron(III)chelates by HPLC and titration. Recoveries of DTPA, EDTA, and NTA from a standard mixture of analytes by UV–Vis were 107±7, 101±12 and 94±13%, respectively, and the recovery of the total amount of complexing agents was 99±4%. The limits of detection for DTPA, EDTA, and NTA were 667, 324, and 739 mol L^–1, respectively. In HPLC measurements the optimized mobile phase contained 0.03 mol L^–1 sodium acetate, 0.002 mol L^–1 tetrabutylammonium bromide, and 5% methanol at pH 3.15 and the detection was by UV–Vis detection at 254 nm. All three complexing agents could be separated from each other in a simultaneous analysis in less than 5 min. The limits of detection were 0.34, 0.27, and 0.62 mol L^–1 for DTPA, EDTA, and NTA, respectively. The total amounts of the analytes measured in the dishwashing detergents by the three techniques were found to be highly comparable (ANOVA: F=0.04, P=0.96). R² values were 0.99 for EDTA, 0.99 for NTA, and 0.99 for all the results when UV–Vis and HPLC determinations were compared using regression lines. The UV–Vis and HPLC methods were proved to be viable also for analyses of natural and pulp mill waters. The absence of matrix interferences was verified by the standard addition technique.     

The structure and complexation equilibria of copper(II) with 4-(\bar 4-nitrophenyl)azo-2-phenyloxazolin-5-one

Summary A spectrophotometric method for determining trace amounts of Cu^II using 4-( -nitro-phenyl)azo-2-phenyloxazolin-5-one has been devised. With this reagent, Cu^II forms a stable chelate, in the 6–9.5 pH range which obeys Beer's law at 555 nm with a molar absorptivity of 4.50 × 10³ mol^–1 cm². Other copper-group metals do not interfere with this process. The stoichiometry and stability constant of the copper chelate has been determined using spectrophotometric, potentiometric and conductometric methods.     

New metal chelates of 5-amino-4-azopyrazoles: The crystal and molecular structure of bis{1-phenyl-3-methyl-4-(<Emphasis Type="Italic">p</Emphasis>-tolyl)azo-5-(<Emphasis Type="Italic">p</Emphasis>-carboxymethoxyphenyl)pyrazolamidato}copper(II)

The reactions of 1,3-alkyl(aryl) derivatives of 5-amino-4-azopyrazoles (HL) with copper(2+) acetate afford metal chelates CuL₂. Complexes with the CuN₄ chromophore containing a substituted amino group (X = NR) as a donor, like their azomethine analogues, have a pseudotetrahedral structure. Copper chelates with X = NH are planar. The X-ray diffraction data and an additional hyperfine structure (ahfs) from ¹⁵N atoms of the azo group in the labeled complexes provide evidence for the formation of six-membered metallocycles. The coordination polyhedron in bis{1-phenyl-3-methyl-4-(p-tolyl)azo-5-(p-carboxymethoxyphenyl)pyrazolamidato}Cu(II) can be described as a pseudotetrahedron.     

Reaction of perfluorinated 1-ethyl-, 1,1-diethyl-, and 1,2-diethylcyclobutabenzenes with pentafluorobenzene in SbF<Subscript>5</Subscript>

Perfluoro(1-ethyl-1,2-dihydrocyclobutabenzene) reacts with pentafluorobenzene in SbF5 to give perfluoro(1-ethyl-2-phenyl-1,2-dihydrocyclobutabenzene). Analogous reaction of a mixture of perfluoro(1,1-diethyl-1,2-dihydrocyclobutabenzene) and perfluoro(1,2-diethyl-1,2-dihydrocyclobutabenzene) leads to the formation (after hydrolysis of the reaction mixture) of perfluorinated 7-phenyl-8,8-diethylbicyclo[4.2.0]octa-1,4,6-trien-3-one, 1,1-diethyl-2-(4-oxocyclohexa-2,5-dienylidene)-1,2-dihydrocyclobutabenzene, and 2-(pent-2-en-3-yl)benzophenone (from the 1,1-isomer) and perfluorinated (E)-1,2-diethyl-1-phenyl-1,2-dihydrocyclobutabenzene, 7,8-diethyl-8-phenylbicyclo[4.2.0]octa-1,4,6-trien-3-one, and 1-[2-(1-phenylprop-1-en-1-yl)-phenyl]propan-1-one (from the 1,2-isomer).     

Reaction of ethylene oxide with n-phenylated isomers of 1,2,4-triazoline-3-thione and 1-phenyltetrazoline-5-thione

It is demonstrated that ethylene oxide forms N--hydroxyethyl derivatives of the corresponding triazolin-3-ones in the reaction with 1-phenyl- and 4-phenyl-1,2,4-triazolin-3-thiones and with 3--hydroxyethylthio derivatives of 1-phenyl- and 4-phenyl-1,2,4-triazole in acetic acid. 1-Phenyltetrazolin-5-thione reacts similarly with ethylene oxide. Under the influence of ethylene oxide, 2-methyl-4-phenyl-1,2,4-triazolin-3-thione is converted to 2-methyl-4-phenyl-1,2,4-triazolin-3-one.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 700–703, May, 1971.     

Novel synthesis of (24R,6E)-24-ethylcholest-6-hydroxyimino-4-en-3-one, a steroidal oxime fromCinachyrella spp. sponges

(24R,6E)-24-ethylcholest-6-hydroxyimino-4-en-3-one (1), which was isolated previously fromCinachyrella spp. sponges, is synthesized in five steps from -sitosterol in 30% overall yield.Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, Belarus, 220141, Minsk, ul. Akad. Kuprevicha, 5/2. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 149–151, March–April, 2000.     

The interaction of alkaline solutions of potassium borohydride with LaNi4.5M0.5 (M = Ni,Mn, Cr,Co, Fe,Cu, Al) intermetallic compounds

The behavior of LaNi_4.5M_0.5 (M = Ni, Mn, Cc Co, Fe, Cu, Al) interinctallic compounds (IMC) in alkaline solutions of KBH₄ (0.1; 1.0; 4.0 mol L^–1 KOH) Was investigated in the temperature range 298–318 K. The catalytic hydrolysis of KBH₄ is zero order with respect to KBH₄ and not order with respect to IMC. Activation energies of the catalytic hydrolysis of KBH₄ in the presence of' IMC are in the range of 60–65 U mol^–1. The rate of hydrolysis of KBH₄ increases with the concentration of the KOH solution. The hydrogenation of LaNi_4.5M_0.5 in alkaline solutions of KBH₄ yields -hybride phases for M = Min, Cr, Co, Cu, Al and -hybride phases for M = Ni, Fe.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1632–1635, July, 1996.     

Molecular structure of (4Z)-{[(1<Emphasis Type="Italic">R</Emphasis>,6<Emphasis Type="Italic">S</Emphasis>)-7,7-dimethyl-2-oxo-3-oxabicyclo [4.1.0] hept-4-en-4-yl]methylene}-2-phenyl-l,3-oxazol-5(4H)-one

The (4Z)- {[(1R, 6S)-7,7-dimethyl-2-oxo-3-oxabicyclo[4.1.0]hept-4-en-4-yl]methylene}-2-phenyl-1,3-oxazol-5(4H)-one compound is synthesized and its molecular structure is determined.     

2,3-Diferrocenylcyclopropenone in the reaction with organomagnesium compounds

The reactions of 2,3-diferrocenylcyclopropenone with ethyl- and benzylmagnesium chlorides afford 3,3-diethyl- and 3,3-dibenzyl-1,2-diferrocenylcyclopropenes along with products of nucleophilic opening of the three-membered ring: ,-unsaturated and saturated ketones (cis-1,2-diferrocenylpent-1-en-3-one and cis-1,2-diferrocenyl-4-phenylbut-1-en-3-one, 4,5-diferrocenylheptan-3-one, and 3,4-diferrocenyl-1,5-diphenylpentan-2-one). The products of insertion of intermediate diferrocenyl(vinyl)carbene at one of the -bonds of the starting 2,3-diferrocenylcyclopropenone were also isolated: 4-(2-oxo-1-ferrocenylbutyl)- and 4-(2-oxo-3-phenyl-1-ferrocenylpropyl)-2,3,4-triferrocenylcyclobutenones. 3,3-Dibenzyl-1,2-diferrocenylcyclopropene and one of the diastereomers of 4,5-diferrocenylheptan-3-one were studied by X-ray diffraction analysis.     

A homogeneous catalyst made of poly(4-vinylpyridine-co-N-vinylpyrrolidone)-Pd(0) complex for hydrogenation of aromatic nitro compounds

Poly(4-vinylpyridine-co-N-vinylpyrrolidone)(VPy-co-NVP) and its palladium complex (VPy–NVP–Pd) were prepared. The palladium complex was used as catalyst for the hydrogenation of some nitroaromatics. The molar content of VPy units in VPy-co-NVP was determined as 31.25% by ¹H NMR. VPy–NVP–Pd can be easily resolved in ethanol forming a homogeneous catalytic hydrogenation system together with substrates. The optimum catalytic activity for hydrogenation of nitrobenzene appeared when VPy/Pd molar ratio was 2. The catalytic behavior of the catalyst was found to be greatly affected by the type and concentration of added alkalies. The highest hydrogenation rate for nitrobenzene was found in a 0.1 mol/l ethanol solution of potassium hydroxide. The catalytic stability was examined by using nitrobenzene and 4-nitroanisole as substrates.     

Synthesis of pregnane derivatives

Pregnane derivatives have been obtained from the cyanohydrins of androst-4-en-3, 17-dione and of 3-acetoxyandrost-5-en-17-one. It has been shown that when both a nitrile group and an ethylenedioxy group are present in an androstane derivative a Grignard reaction in anisole takes place simultaneously at the two groups.S. Ordzhonikidze All-Union Scientific-Research Institute of Pharmaceutical Chemistry, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 324–327, May–June, 1984.