- A silicododecamolybdate/pyridinium-tetrazole hybrid molecular salt as a catalyst for the epoxidation of bio-derived olefins
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The hybrid polyoxometalate (POM) salt (Hptz)4[SiMo12O40]?nH2O (1) (ptz = 5-(2-pyridyl)tetrazole) has been prepared, characterized by X-ray crystallography, and examined as a catalyst for the epoxidation of cis-cyclooctene (Cy) and bio-derived olefins, namely dl-limonene (Lim; a naturally occurring monoterpene found in the rinds of citrus fruits), methyl oleate and methyl linoleate (fatty acid methyl esters (FAMEs) obtained by transesterification of vegetable oils). The crystal structure of 1 consists of α-Keggin-type heteropolyanions, [SiMo12O40]4-, surrounded by space-filling and charge-balancing 2-(tetrazol-5-yl)pyridinium (Hptz+) cations, as well as by a large number of water molecules of crystallization (n = 9). The water molecules mediate an extensive three-dimensional (3D) hydrogen-bonding network involving the inorganic anions and organic cations. For the epoxidation of the model substrate Cy in a nonaqueous system (tert-butylhydroperoxide as oxidant), the catalytic performance of 1 (100% epoxide yield at 24 h, 70 °C) was superior to that of the tetrabutylammonium salt (Bu4N)4[SiMo12O40] (2) (63% epoxide yield at 24 h), illustrating the role of the counterion Hptz+ in enhancing catalytic activity. The hybrid salt 1 was effective for the epoxidation of Lim (69%/85% conversion at 6 h/24 h) and the FAMEs (87–88%/100% conversion at 6 h/24 h), leading to useful bio-based products (epoxides, diepoxides and diol products).
- Nunes, Martinique S.,Neves, Patrícia,Gomes, Ana C.,Cunha-Silva, Luís,Lopes, André D.,Valente, Anabela A.,Pillinger, Martyn,Gon?alves, Isabel S.
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- Selective Catalytic Synthesis of 1,2- and 8,9-Cyclic Limonene Carbonates as Versatile Building Blocks for Novel Hydroxyurethanes
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The selective catalytic synthesis of limonene-derived monofunctional cyclic carbonates and their subsequent functionalisation via thiol–ene addition and amine ring-opening is reported. A phosphotungstate polyoxometalate catalyst used for limonene epoxidation in the 1,2-position is shown to also be active in cyclic carbonate synthesis, allowing a two-step, one-pot synthesis without intermittent epoxide isolation. When used in conjunction with a classical halide catalyst, the polyoxometalate increased the rate of carbonation in a synergistic double-activation of both substrates. The cis isomer is shown to be responsible for incomplete conversion and by-product formation in commercial mixtures of 1,2-limomene oxide. Carbonation of 8,9-limonene epoxide furnished the 8,9-limonene carbonate for the first time. Both cyclic carbonates underwent thiol–ene addition reactions to yield linked di-monocarbonates, which can be used in linear non-isocyanate polyurethanes synthesis, as shown by their facile ring-opening with N-hexylamine. Thus, the selective catalytic route to monofunctional limonene carbonates gives straightforward access to monomers for novel bio-based polymers.
- Maltby, Katarzyna A.,Hutchby, Marc,Plucinski, Pawel,Davidson, Matthew G.,Hintermair, Ulrich
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supporting information
p. 7405 - 7415
(2020/05/25)
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- Sustainable catalytic protocols for the solvent free epoxidation and: Anti -dihydroxylation of the alkene bonds of biorenewable terpene feedstocks using H2O2 as oxidant
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A tungsten-based polyoxometalate catalyst employing aqueous H2O2 as a benign oxidant has been used for the solvent free catalytic epoxidation of the trisubstituted alkene bonds of a wide range of biorenewable terpene substrates. This epoxidation protocol has been scaled up to produce limonene oxide, 3-carene oxide and α-pinene oxide on a multigram scale, with the catalyst being recycled three times to produce 3-carene oxide. Epoxidation of the less reactive disubstituted alkene bonds of terpene substrates could be achieved by carrying out catalytic epoxidation reactions at 50 °C. Methods have been developed that enable direct epoxidation of untreated crude sulfate turpentine to afford 3-carene oxide, α-pinene oxide and β-pinene oxide. Treatment of crude epoxide products (no work-up) with a heterogeneous acid catalyst (Amberlyst-15) results in clean epoxide hydrolysis to afford their corresponding terpene-anti-diols in good yields.
- Cunningham, William B.,Tibbetts, Joshua D.,Hutchby, Marc,Maltby, Katarzyna A.,Davidson, Matthew G.,Hintermair, Ulrich,Plucinski, Pawel,Bull, Steven D.
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supporting information
p. 513 - 524
(2020/02/13)
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- Limonene oxyfunctionalization over Cu-modified silicates employing hydrogen peroxide and t-Butyl hydroperoxide: Reaction pathway analysis
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Limonene oxidation over Cu-nanostructured mesoporous materials was studied. Three solids with different copper content were synthesized employing the template-ion exchange method, and physically-chemically analyzed by a multi-technical characterization. The performance of the molecular sieves as catalysts in the liquid phase oxyfunctionalization of limonene, employing hydrogen peroxide (H2O2) or t-butyl hydroperoxide (TBHP) as oxidants was evaluated. All synthesized Cu-MCM materials were active in the reaction. The obtained results showed that the used oxidant had an important influence on the products distribution under the employed conditions. With H2O2, compounds of high added value such as limonene oxide, carveol and carvone were mainly obtained. Meanwhile, with TBHP, limonene hydroperoxide turned out to be the major product. Finally, a reaction mechanism was proposed for each oxidant.
- Vaschetti, Virginia M.,Cánepa, Analía L.,Barrera, Deicy,Sapag, Karim,Eimer, Griselda A.,Casuscelli, Sandra G.
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- Systematic synthetic study of four diastereomerically distinct limonene-1,2-diols and their corresponding cyclic carbonates
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In order to produce versatile and potentially functional terpene-based compounds, a (R)-limonene-derived diol and its corresponding five-membered cyclic carbonate were prepared. The diol (cyclic carbonate) comprises four diastereomers based on the stereochemical configuration of the diol (and cyclic carbonate) moiety. By choosing the appropriate starting compounds (trans- and cis-limonene oxide) and conditions, the desired diastereomers were synthesised in moderate to high yields with, in most cases, high stereoselectivity. Comparison of the NMR data of the obtained diols and carbonates revealed that the four different diastereomers of each compound could be distinguished by reference to their characteristic signals.
- Morikawa, Hiroshi,Yamaguchi, Jun-ichi,Sugimura, Shun-ichi,Minamoto, Masato,Gorou, Yuuta,Morinaga, Hisatoyo,Motokucho, Suguru
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supporting information
p. 130 - 136
(2019/01/30)
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- Oxy-functionalization of olefins with neat and heterogenized binuclear V(IV)O and Fe(II)complexes: Effect of steric hindrance on product selectivity and output in homogeneous and heterogeneous phase
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Neat {[VO(sal2bz)]2; [Fe(sal2bz)(H2O)2]2·2H2O} and zeolite-Y immobilized {[VO(sal2bz)]2-Y; [Fe(sal2bz)(H2O)2]2-Y} binuclear complexes have been prepared and characterized by spectroscopic techniques (IR, UV–vis), elemental analyses (CHN, ICP-OES), thermal study (TGA), scanning electron micrograph (SEM), adsorption study (BET)and X-ray diffraction (XRD)patterns. Neat (homogeneous)and immobilized (heterogeneous)complexes were employed as catalysts in the oxidation of olefins, namely, cyclohexene, limonene and α-pinene in the presence of 30% hydrogen peroxide. 100% conversion of cyclohexene and α-pinene was obtained while limonene was oxidized up to 90%. Homogeneous catalysts showed highly selective result as neat [VO(sal2bz)]2 complex has provided 87% cyclohexane-1,2-diol and neat [Fe(sal2bz)(H2O)2]2·2H2O complex has provided 79% verbenone in oxidation of cyclohexene and α-pinene, respectively. We have observed that due to steric hindrance, formation of olefinic oxidation products increases on moving from α-pinene to limonene and limonene to cyclohexene. Additionally. recovered heterogeneous catalysts showed intact results up to two consecutive runs. Probable catalytic mechanism has been proposed for oxidation of cyclohexene.
- Parmar, Digvijaysinh K.,Butani, Pinal M.,Thumar, Niraj J.,Jasani, Pinal M.,Padaliya, Ravi V.,Sandhiya, Paba R.,Nakum, Haresh D.,Khan, Md. Nasim,Makwana, Dipak
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- Performance of chiral tetracarbonylmolybdenum pyrindanyl amine complexes in catalytic olefin epoxidation
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Tetracarbonylmolybdenum(0) complexes of the type cis-[Mo(CO)4(L)] containing chiral 7-(1-pyrindanyl) amine ligands were prepared and found to be effective precatalysts for the epoxidation of achiral (cis-cyclooctene) and prochiral (DL-limonene and trans-β-methylstyrene) olefins at 55 °C. Epoxides were the only products formed from cis-cyclooctene (100% yield) and trans-β-methylstyrene (100% selectivity at 82–85% conversion), and the main products formed from DL-limonene (80–82% 1,2-epoxide selectivity at 85% conversion). Characterization of recovered catalysts revealed that the precatalysts were transformed in situ to stable polyoxomolybdate salts containing the β-octamolybdate anion [β-Mo8O26]4?, which was responsible for the catalytic reaction.
- Neves, Patrícia,Nogueira, Lucie S.,Valente, Anabela A.,Pillinger, Martyn,Gon?alves, Isabel S.,Sampaio-Dias, Ivo E.,Sousa, Carlos A.D.,Rizzo-Aguiar, Fabio,Rodríguez-Borges, José E.
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- Influence of ligand substitution on molybdenum catalysts with tridentate Schiff base ligands for the organic solvent-free oxidation of limonene using aqueous TBHP as oxidant
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The oxidation of limonene by aqueous TBHP has been analyzed in the presence of molybdenum complexes [MoO2L]2 as catalysts with five different tridentate ligands L in the absence of organic solvents (greener reaction conditions). The ligands are based on a common salicylidene amino(thio)phenolate, SA(T)P, backbone with differences in the coordination sphere (ONO for L = SAP vs. ONS for L = SATP) or in the salicyl moiety functionalization by OH groups for the ONO ligands. The process gives a regioselective endocyclic epoxidation to a kinetically controlled 1:1 mixture of the cis-LimO and trans-LimO epoxides and/or the isomeric diols ax-LimD and eq-LimD by the subsequent ring opening in the presence of water, with a product distribution that depends on the ligand, reaction time and temperature. In combination with control experiments of the cis/trans-LimO ring opening, the investigations demonstrate the catalytic action of the metal complexes in both the epoxidation and the ring opening steps, with the cis-LimO stereospecifically producing the ax-LimD product and the less reactive trans-LimO leading to a 4:3 mixture of ax-LimD and eq-LimD. The ONS system [MoO2(SATP)]2 exhibits the highest catalytic activity in both steps.
- Wang, Weili,Agustin, Dominique,Poli, Rinaldo
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- Kinetics of the Aqueous Phase Reactions of Atmospherically Relevant Monoterpene Epoxides
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Laboratory and field measurements have demonstrated that an isoprene-derived epoxide intermediate (IEPOX) is the origin of a wide range of chemical species found in ambient secondary organic aerosol (SOA). In order to explore the potential relevance of a similar mechanism for the formation of monoterpene-derived SOA, nuclear magnetic resonance techniques were used to study kinetics and reaction products of the aqueous-phase reactions of several monoterpene epoxides: β-pinene oxide, limonene oxide, and limonene dioxide. The present results, combined with a previous study of α-pinene oxide, indicate that all of these epoxides will react more quickly than IEPOX with aqueous atmospheric particles, even under low-acidity conditions. As for α-pinene oxide, the observed products can be mainly rationalized with a hydrolysis mechanism, and no long-lived organosulfate or nitrate species nor species that retain the β-pinene bicyclic carbon backbone are observed. As bicyclic ring-retaining organosulfate and nitrate species have been previously observed in monoterpene-derived SOA, it appears that monoterpene-derived epoxides may not be as versatile as IEPOX in producing a range of SOA species, and other mechanisms are needed to rationalize organosulfate and nitrate formation.
- Cortés, DIego A.,Elrod, Matthew J.
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p. 9297 - 9305
(2017/12/18)
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- Synthesis, characterization and catalytic application of a new organometallic oligomer based on polyhedral oligomeric silsesquioxane
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Although homogeneous catalysts provide high performance and selectivity, the difficulty of separation and recycling of these catalysts has bothered the scientific community worldwide. Therefore, the demand for heterogeneous catalysts that possess the advantages of homogeneous ones, with ease of separation and recyclability remains a topic of major impact. The oligomeric catalyst synthesized in this work was characterized using elemental analysis, Fourier transform infrared, 13C NMR, 29Si NMR and energy-dispersive X-ray spectroscopies, X-ray diffraction, thermogravimetric analysis, scanning electron microscopy and Brunauer–Emmett–Teller analysis and compared to its homogeneous counterpart [W(CO)3Br2(ATC)] in the epoxidation of 1-octene, cyclooctene, (S)-limonene, cis-3-hexen-1-ol, trans-3-hexen-1-ol and styrene. The results showed that the percentage conversion for the homogeneous species [W(CO)3Br2(ATC)] was slightly higher than for the oligomeric catalyst (POSS-ATC-[W(CO)3Br2]). Furthermore, the selectivity for epoxide of the oligomeric catalyst was greater than that of the homogeneous catalyst by about 25% when (S)-limonene was used. Great conversions (yields) of products were obtained with a wide range of substrates and the catalyst was recycled many times without any substantial loss of its catalytic activity.
- Vieira, Eduardo Guimar?es,Silva, Rafael Oliveira,Junior, Enes Furlani,Dias Filho, Newton Luiz
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- Towards a global greener process: from solvent-less synthesis of molybdenum(vi) ONO Schiff base complexes to catalyzed olefin epoxidation under organic-solvent-free conditions
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Nine Schiff base ligands derived from o-hydroxyaldehydes (2-hydroxybenzaldehyde, 2-hydroxy-3-methoxybenzaldehyde, 2-hydroxy- 1-naphthaldehyde) and nine corresponding dioxomolybdenum(vi) complexes, cis-[MoO2L(CH3OH)] or cis-[MoO2L(CH3OH)]·CH3OH and dinuclear [MoO2L]2, have been prepared using the conventional solution-based method as well as mechanochemically, by liquid assisted grinding (LAG). All products have been characterised by means of IR spectroscopy, thermal analyses and also by powder and five molybdenum complexes by single crystal X-ray diffraction. The crystal structure analysis of mononuclear complexes reveal distorted octahedral Mo(vi) coordination by ONO donor atoms from a dianionic tridentate Schiff base ligand, two oxido oxygen atoms from the MoO22+ moiety and an oxygen atom from the MeOH molecule trans to the oxido oxygen atom. Due to the trans effect of the oxido oxygen atom, Mo-O(MeOH) is the longest bond distance within the Mo coordination sphere and it expected to be the point of maximum reactivity of the complexes. All complexes have been studied as pre(catalysts) for the epoxidation of cis-cyclooctene, cyclohexene and (R)-limonene using aqueous tert-butyl peroxide (TBHP) as the oxidant and in the absence of an organic solvent.
- Cindri?, Marina,Pavlovi?, Gordana,Katava, Robert,Agustin, Dominique
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p. 594 - 602
(2017/02/05)
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- Synthesis of two new Mo(II) organometallic catalysts immobilized on POSS for application in olefin oxidation reactions
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The purpose of this work was the preparation and characterization of two new catalysts POSS-ATZAc-[Mo(η3-C3H5)Br(CO)2] (POSS-Mo-I) and POSS-ATZAc-[Mo(CO)3Br2] (POSS-Mo-II). The new heterogeneous catalysts were characterized by several techniques and used as catalysts for the epoxidation of olefins, presenting high catalytic activity. To study and optimize the syntheses of the heterogeneous catalysts, immobilization experiments of the [Mo(η3-C3H5)Br(CO)2(NCMe)2] and [Mo(CO)3Br2(NCMe)2] organometallic complexes on the modified polyhedral oligomeric silsesquioxane were performed. The sorption properties of the modified silsesquioxane showed to be dependent of the contact time, concentration and temperature. Catalysts were tested in the epoxidation of six olefins and compared with homogeneous species [Mo(η3-C3H5)Br(CO)2(ATZAc)] (Mo-I) and [Mo(CO)3Br2(ATZAc)] (Mo-II). To the best of our knowledge, this paper is the first that has reported the preparation and characterization of two new heterogeneous catalysts, as well as the comparison with homogeneous species for catalytic epoxidation of olefins.
- Vieira, Eduardo Guimar?es,Dal-Bó, Alexandre Gon?alves,Frizon, Tiago Elias Allievi,Dias Filho, Newton Luiz
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- Catalytic homogeneous oxidation of monoterpenes and cyclooctene with hydrogen peroxide in the presence of sandwich-type tungstophosphates [M4(H2O)2(PW9O34)2]n?, M = CoII, MnII and FeIII
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Catalytic efficiency of tetrabutylammonium salts of sandwich tungstophosphates B‐α‐[M4(H2O)2(PW9O34)2]n?, M = CoII, MnII, FeIII, was studied in the oxidation of (R)-(+)-limonene, geraniol, linalool, linalyl acetate, carveol, and cis-cyclooctene with hydrogen peroxide, in acetonitrile. Oxidation of (R)-(+)-limonene gave limonene-1,2-diol as main product. Epoxidation of linalool takes place preferentially at the more substituted 6,7-double bond, the corresponding 6,7-epoxide reacting further, yielding furano- and pyrano-oxides, via intramolecular cyclization. Oxidation of linalyl acetate occurred preferentially at the more substituted 6,7-double bond for Mn4(PW9)2, affording 6,7-epoxide at 82% selectivity. Linalyl acetate 1,2-epoxide was the major product with 51% and 77% selectivity for Co4(PW9)2 and Fe4(PW9)2, respectively. Oxidation of carveol occurred with very good conversions in the presence of Mn4(PW9)2, Co4(PW9)2 and Fe4(PW9)2, yielding carvone and carveol 1,2-epoxide in similar amounts. Oxidation of cis-cyclooctene gave only the epoxide, while oxidation of geraniol at room temperature afforded 2,3-epoxygeraniol as the major product.
- Santos, Isabel C.M.S.,Gamelas, José A.F.,Duarte, Tiago A.G.,Sim?es, Mário M.Q.,Neves, M. Gra?a P.M.S.,Cavaleiro, José A.S.,Cavaleiro, Ana M.V.
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p. 593 - 599
(2016/12/16)
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- Oxidation of olefins with H2O2 catalyzed by gallium(III) nitrate and aluminum(III) nitrate in solution
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Soluble gallium and aluminum nitrates (simple salts of non-transition metals) are good catalysts for the epoxidation of olefins (cyclooctene, dec-1-ene) including terpenes (carvone, limonene) with hydrogen peroxide in ethyl acetate or tetrahydrofurane (THF). Typically, the gallium salt is more efficient in comparison with the aluminum derivative. Products are formed in yields up to 93%, turnover numbers (TONs) attained 40. Addition of trifluoroacetic acid or pyrazine-2-carboxylic acid (PCA) accelerates the reaction and improves the yield. In striking contrast, added 2,2′-bipyridine or phenanthroline dramatically inhibit the oxidation.
- Mandelli, Dalmo,Kozlov, Yuriy N.,da Silva, Cezar A.R.,Carvalho, Wagner A.,Pescarmona, Paolo P.,Cella, Daniele de A.,de Paiva, Polyana T.,Shul'pin, Georgiy B.
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p. 216 - 220
(2016/09/19)
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- Syntheses and catalytic activities of new metallodendritic catalysts
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This investigation presents the syntheses of new metallodendritic catalysts from a silsesquioxane core (Silsesq-PrNH3+Cl-) via a new route. For optimization of the syntheses of the catalysts, reaction times, thermodynamic effects, and the amounts of [Mo(η3-C3H5)Br(CO)2(NCCH3)2] (1) and [Mo(CO)3Br2(NCCH3)2] (2) complexes fixed on the second-generation dendrimer (PDG2.0) were studied. After the optimization studies and with the objective of application in catalysis, the catalysts were prepared by reaction of PDG2.0 with the organometallic complexes and characterized by elemental analysis (CNH), FTIR, 13C and 29Si NMR, XRD, TGA, SEM, EDS and BET. The metallodendritic catalysts were tested in the epoxidation of olefins and shown to be a vigorous catalyst with conversion rates between 76 and 97% for PDG2.0-[(Mo(η3-C3H5)(CO)2Br)8] and 30-80% for PDG2.0-[(Mo(CO)3Br2)5], and a high selectivity in the formation of epoxides using tertbutyl hydroperoxide (TBHP) as an oxidant. The catalysts remain highly active after being used for at least 5 cycles. To the best of our knowledge, this study is the first to have reported the preparation of these new dendritic catalysts, as well as the catalytic comparison with their previous generations in the epoxidation of 1-octene, cyclooctene, (S)-limonene, cis-3-hexen-1-ol, trans-3-hexen-1-ol and styrene.
- Vieira, Eduardo Guimar?es,Silva, Rafael Oliveira,Dal-Bó, Alexandre Gon?alves,Frizon, Tiago Elias Allievi,Filho, Newton Luiz Dias
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p. 9403 - 9414
(2016/11/09)
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- Metal oxide-triazole hybrids as heterogeneous or reaction-induced self-separating catalysts
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The hybrid metal oxide-triazole materials [MoO3(trz)0.5] (1) and [W2O6(trz)] (2) (trz?=?1,2,4-triazole) have been hydrothermally synthesized and characterized by different techniques (TGA, SEM, 1H and 13C MAS NMR, FT-IR spectroscopy, and structure determination by Rietveld analysis of high resolution synchrotron powder XRD data). Materials 1 and 2 display distinct behaviors when applied as catalysts for oxidation reactions with alcohol, aldehyde, olefin and sulfide substrates, and are more effective with hydrogen peroxide as the oxidant than with tert-butylhydroperoxide. The MoVI hybrid 1 transforms into soluble active species during cis-cyclooctene epoxidation with H2O2. When consumption of H2O2 reaches completion, spontaneous reassembly of the 2-dimensional molybdenum oxide network of 1 takes place and the hybrid precipitates as a microcrystalline solid that can be easily separated and recycled. Reaction-induced self-separation behavior occurs with 1, H2O2 and other substrates such as methyl oleate and methylphenylsulfide. The WVI hybrid 2 behaves differently, preserving its structural features throughout the heterogeneous catalytic process.
- Amarante, Tatiana R.,Neves, Patrícia,Valente, Anabela A.,Paz, Filipe A. Almeida,Pillinger, Martyn,Gon?alves, Isabel S.
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p. 354 - 367
(2016/07/06)
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- Catalytic alcoholysis of epoxides using metal-free cucurbituril-based solids
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Metal-free cucurbit[7]uril (CB7) solid-state assemblies promote acid-catalysed alcoholysis of aliphatic and aromatic epoxides under mild conditions to give β-alkoxy alcohols, which are important intermediates for the synthesis of a vast range of compounds such as bioactive pharmaceuticals. The catalytic process is heterogeneous and the catalyst can be reused in consecutive runs without any reactivation treatment. The acid species responsible for the catalytic activity of CB7 may be entrapped hydronium ions.
- Bruno, Sofia M.,Gomes, Ana C.,Oliveira, Tania S. M.,Antunes, Margarida M.,Lopes, André D.,Valente, Anabela A.,Gon?alves, Isabel S.,Pillinger, Martyn
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supporting information
p. 3873 - 3877
(2016/05/24)
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- Efficient Epoxide Hydrolase Catalyzed Resolutions of (+)- and (-)-cis/trans-Limonene Oxides
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The synthesis of enantiomerically pure cis- and trans-limonene oxides and their corresponding diols from easily accessible raw materials has been of much interest for a long time. A straightforward one-step biocatalytic resolution of the (+)-cis/trans limonene oxide and the (-)-cis/trans-limonene oxide has been investigated. Epoxide hydrolases showing complementary stereoselectivity were recombinantly expressed in Escherichia coli, which allowed easy purification. The conditions for the selective epoxide hydrolase catalyzed ring-opening reactions have been optimized and enabled the preparation of all limonene oxide enantiomers. The described utilization of recombinant epoxide hydrolases for the synthesis of all limonene oxide enantiomers was superior to chemical routes and represents a highly resource-efficient one-step preparation.
- Ferrandi, Erica Elisa,Marchesi, Carlotta,Annovazzi, Celeste,Riva, Sergio,Monti, Daniela,Wohlgemuth, Roland
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p. 3171 - 3178
(2015/10/19)
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- Comparative study of the bioconversion process using R-(+)- and S-(-)-limonene as substrates for Fusarium oxysporum 152B
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This study compared the bioconversion process of S-(-)-limonene into limonene-1,2-diol with the already established biotransformation of R-(+)-limonene into α-terpineol using the same biocatalyst in both processes, Fusarium oxysporum 152B. The bioconversion of the S-(-)-isomer was tested on cell permeabilisation under anaerobic conditions and using a biphasic system. When submitted to permeabilisation trials, this biocatalyst has shown a relatively high resistance; still, no production of limonene-1,2-diol and a loss of activity of the biocatalyst were observed after intense cell treatment, indicating a complete loss of cell viability. Furthermore, the results showed that this process can be characterised as an aerobic system that was catalysed by limonene-1,2-epoxide hydrolase, had an intracellular nature and was cofactor-dependent because the final product was not detected by an anaerobic process. Finally, this is the first report to characterise the bioconversion of R-(+)- and S-(-)-limonene by cellular detoxification using ultra-structural analysis.
- Molina, Gustavo,Bution, Murillo L.,Bicas, Juliano L.,Dolder, Mary Anne Heidi,Pastore, Gláucia M.
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p. 606 - 613
(2015/02/19)
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- Comparative study of the bioconversion process using R-(+)- and S-(-)-limonene as substrates for Fusarium oxysporum 152B
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This study compared the bioconversion process of S-(-)-limonene into limonene-1,2-diol with the already established biotransformation of R-(+)-limonene into α-terpineol using the same biocatalyst in both processes, Fusarium oxysporum 152B. The bioconversion of the S-(-)-isomer was tested on cell permeabilisation under anaerobic conditions and using a biphasic system. When submitted to permeabilisation trials, this biocatalyst has shown a relatively high resistance; still, no production of limonene-1,2-diol and a loss of activity of the biocatalyst were observed after intense cell treatment, indicating a complete loss of cell viability. Furthermore, the results showed that this process can be characterised as an aerobic system that was catalysed by limonene-1,2-epoxide hydrolase, had an intracellular nature and was cofactor-dependent because the final product was not detected by an anaerobic process. Finally, this is the first report to characterise the bioconversion of R-(+)- and S-(-)-limonene by cellular detoxification using ultra-structural analysis.
- Molina, Gustavo,Bution, Murillo L.,Bicas, Juliano L.,Dolder, Mary Anne Heidi,Pastore, Glucia M.
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p. 606 - 613
(2015/04/16)
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- Oxidative catalytic versatility of a trivacant polyoxotungstate incorporated into MIL-101(Cr)
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The first immobilization of the trivacant Keggin-type polyoxometalate ([A-PW9O34]9-, PW9) to prepare a novel heterogeneous oxidative catalyst is here reported. PW9 was incorporated into the cavities of the chromium terephthalate metal-organic framework MIL-101(Cr). Characterization of the composite PW9@MIL-101 by powder X-ray diffraction, SEM-EDX, FT-IR, FT-Raman spectroscopy, N 2 adsorption-desorption isotherms and 31P solid-state NMR confirmed that the structures of MIL-101 and the polyoxometalate anion were retained after immobilization. The composite PW9@MIL-101 revealed versatility as a heterogeneous catalyst to oxidize efficiently monoterpenes as well as to reach a complete desulfurization of a model oil containing the most refractory sulfur compounds in fuel, using in both systems acetonitrile as the solvent and H2O2 as the oxidant. Complete conversion of geraniol to 2,3-epoxygeraniol was achieved after the first 30 min at room temperature, while the total desulfurization of the model oil containing 1707 ppm of sulfur was attained after 2 h. In both systems the catalyst was recyclable for various cycles without a significant loss of activity. The stability and heterogeneity of the catalyst were confirmed by several techniques and by leaching tests. the Partner Organisations 2014.
- Granadeiro, Carlos M.,Barbosa, Andre D. S.,Ribeiro, Susana,Santos, Isabel C. M. S.,De Castro, Baltazar,Cunha-Silva, Luis,Balula, Salete S.
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p. 1416 - 1425
(2014/05/06)
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- Heteropoly acid catalysts for the synthesis of fragrance compounds from biorenewables: Isomerization of limonene oxide
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The liquid-phase isomerization of limonene oxide was studied in the presence of heteropoly acid catalysts in aprotic solvents in homogeneous and heterogeneous systems. Among the catalysts were bulk and silica-supported tungstophosphoric acid H3PW12O40 and its acidic Cs salt Cs0.5H0.5PW12O40 (CsPW). The reaction gave dihydrocarvone, a valuable fragrance intermediate, as the main product with turnover numbers of up to 8000. The nature of the solvent had a strong effect on reaction rate and selectivity. CsPW (0.1 mol%) was found to be a highly efficient and truly heterogeneous catalyst for this reaction, providing 82% yield of dihydrocarvone in 1,4-dioxane as a solvent under ambient conditions. This simple catalytic method represents economically attractive route to industrially important compounds starting from bio-renewable substrates easily available from essential oils. The Royal Society of Chemistry 2013.
- Costa, Vinicius V.,Da Silva Rocha, Kelly A.,Kozhevnikov, Ivan V.,Kozhevnikova, Elena F.,Gusevskaya, Elena V.
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p. 244 - 250
(2013/04/10)
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- Bis(pyrazolyl)methanetetracarbonyl-molybdenum(0) as precursor to a molybdenum(VI) catalyst for olefin epoxidation
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Bis(pyrazolyl)methanetetracarbonyl-molybdenum(0), cis-[Mo(CO) 4(BPM)] (1), was prepared from Mo(CO)6 and the ligand bis(pyrazolyl)methane (BPM), and examined as a catalyst precursor for the epoxidation of olefins using tert-butylhydroperoxide (TBHP) as oxidant. Catalytic activities followed the sequence 1-octene Mo-1 h-1 at 55°C and 1175 mol molMo-1 h-1 at 75°C, which compare favourably with those found for other molybdenum carbonyl complexes used as catalyst precursors for the same reaction under similar conditions. Catalytic activities were lower in the presence of organic co-solvents, decreasing in the sequence 1,2-dichloroethane > nitromethane > ethanol > hexane > acetonitrile. It is proposed that the oxodiperoxo complex [MoO(O2)2(BPM)] (2) may be the active catalyst formed in situ by oxidative decarbonylation of 1, since crystals of 2 suitable for structure determination by X-ray diffraction were obtained from the reaction solution recovered after a catalytic run at 55°C with cis-cyclooctene as substrate. In support of this hypothesis, the catalytic performance of 2 for the epoxidation of cyclooctene at 55°C is very similar to that for 1.
- Figueiredo, Sónia,Gomes, Ana C.,Fernandes, José A.,Paz, Filipe A. Almeida,Lopes, André D.,Louren?o, Jo?o P.,Pillinger, Martyn,Gon?alves, Isabel S.
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- Acidic three-liquid-phase microemulsion systems based on balanced catalytic surfactant for epoxidation and sulfide oxidation under mild conditions
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Didecyldimethylammonium tungstate has been designed as a balanced catalytic surfactant to form acidic three-liquid-phase microemulsion systems at room temperature in the presence of water, a non-chlorinated solvent and dimethyldioctylammonium salts (hydrogen sulfate and dihydrogen phosphate). The triphasic system is efficient for the oxidation of olefins, sulfides and thiophenes under mild conditions. Moreover, the recovery and reusability of the catalyst, the straightforward separation of products and catalysts in two distinct phases as well as the possible use of environmentally friendly solvents such as tert-butyl acetate, make this system particularly attractive for catalytic oxidation reactions involving hydrogen peroxide as the primary oxidant under acidic or neutral conditions.
- Fressancourt-Collinet, Marion,Hong, Bing,Leclercq, Loic,Alsters, Paul L.,Aubry, Jean-Marie,Nardello-Rataj, Veronique
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supporting information
p. 409 - 420
(2013/05/22)
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- Water-promoted kinetic separation of trans- and cis-limonene oxides
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The efficient hydrolytic kinetic separation of trans/cis-(R)-(+)-limonene oxides was realized in a 1:1 mixed solvent of water and 1,4-dioxane without additional catalyst. Optically pure trans-(R)-(+)-limonene oxide was recovered in high yield (77%).
- Xu, Zhao-Bing,Qu, Jin
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experimental part
p. 1133 - 1136
(2012/07/28)
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- An octanuclear molybdenum(VI) complex containing coordinatively bound 4,4′-di-tert-butyl-2,2′-bipyridine, [Mo8O 22(OH)4(di-t Bu-bipy)4]: Synthesis, structure, and catalytic epoxidation of bio-derived olefins
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The reaction of [MoO2Cl2(di-tBu-bipy)] (1) (di-tBu-bipy = 4,4′-di-tert-butyl-2,2′-bipyridine) with water at 100-120 °C in a Teflon-lined stainless steel autoclave, in an open reflux system, or in a microwave synthesis system gave the octanuclear complex [Mo 8O22(OH)4(di-tBu-bipy)4] (2) as a microcrystalline powder in good yields. Single crystals of 2 suitable for X-ray diffraction were obtained by the reaction of MoO3 and di-tBu-bipy in water at 160 °C for 3 days. The molecular structure of 2 comprises a purely inorganic core, Mo4O8(μ3-OH) 2(μ2-O)2, attached to two peripheral oxo-bridged binuclear units, Mo2O4(μ2-O) 2(OH)(di-tBu-bipy)2. The inorganic core is composed of a unique assembly of four {MoO5} distorted square pyramids connected to each other via edge-sharing. Overall, the octanuclear complex adopts a highly distorted form strongly resembling an "S"-shaped molecular unit. Complex 2 was applied in the catalytic epoxidation of the biorenewable olefins DL-limonene (Lim) and methyl oleate (Ole), using tert-butylhydroperoxide (TBHP) as an oxygen donor, under mild reaction conditions (55 °C, air). The reactions of Lim and Ole gave the respective epoxide monomers in fairly high selectivities at high conversions (89% 1,2-epoxy-p-menth-8-ene selectivity at 96% Lim conversion; 99% methyl 9,10-epoxystearate selectivity at 94% Ole conversion, reached within 24 h reaction). Iodometric titrations revealed no measurable "non-productive" decomposition of TBHP.
- Amarante, Tatiana R.,Neves, Patricia,Tome, Catia,Abrantes, Marta,Valente, Anabela A.,Paz, Filipe A. Almeida,Pillinger, Martyn,Goncalves, Isabel S.
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experimental part
p. 3666 - 3676
(2012/05/19)
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- Hot water as a mild Bronsted acid catalyst in ring opening reactions of epoxides
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Ring opening of extremely hydrophobic epoxides with water, amines, sodium azide and thiophenol was realized in the mixture solvent of water and 1, 4-dioxane under reflux condition. Hot water was believed to act as a mild Bronsted acid catalyst in the epoxide-opening reactions.
- Xu, Zhaobing,Qu, Jin
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experimental part
p. 1718 - 1725
(2012/04/18)
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- Epoxidation of DL-limonene using an indenyl molybdenum(II) tricarbonyl complex as catalyst precursor
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The complex IndMo(CO)3Me (Ind = η5-C 9H7) is an effective catalyst precursor for the epoxidation of DL-limonene using the following oxidant solutions: (i) commercial tert-butylhydroperoxide in decane (TBHPdec), (ii) commercial aqueous TBHP (TBHPaq) pre-mixed with limonene (TBHPlim), or (iii) TBHPaq pre-mixed with 1,2-dichloroethane (TBHPdce); simple pre-drying treatments of the reaction solutions were applied prior to feeding the catalyst precursor to the batch reactor. The best results were found for the efficiently pre-dried reaction system (iii), which gave higher 1,2-epoxy-p-meth-8-ene yield at 35 min/55 °C than (i) (82% and 73% yield, respectively). This approach avoids the undesirable partial oxidation of decane, which would imply costly work-up procedures to remove high boiling point impurities from the epoxides. These results together with studies on the reactivity of different olefins indicate fairly high regioselectivity toward the epoxidation of the internal double bonds.
- Abrantes, Marta,Bruno, Sofia M.,Tomé, Cátia,Pillinger, Martyn,Gon?alves, Isabel S.,Valente, Anabela A.
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experimental part
p. 64 - 67
(2012/03/09)
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- Hot water-promoted ring-opening of epoxides and aziridines by water and other nucleopliles
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Effective hydrolysis of epoxides and aziridines was conducted by heating them in water at 60 or 100 °C. Other types of nucleophile such as amines, sodium azide, and thiophenol could also efficiently open epoxides and aziridines in hot water. It was proposed that hot water acted as a modest acid catalyst, reactant, and solvent in the hydrolysis reactions.
- Wang, Zhi,Cui, Yong-Tao,Xu, Zhao-Bing,Qu, Jin
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p. 2270 - 2274
(2008/09/19)
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- Exploring the substituent effects on a novel series of C1′-dimethyl-aryl Δ8-tetrahydrocannabinol analogs
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The synthesis and characterization of novel C1′-phenyl-substituted Δ8-THC analogs were previously reported by our laboratory. Within this small series of compounds, the C1′-dimethyl phenyl group was found to impart 13.5-fold selectivity for the CB2 receptor with a Ki 0.91 nM. The current study expands on the previous report by evaluating the effects of aromatic ring substitution on CB1 and CB2 receptor subtype binding and selectivity. The ring substituents synthesized in this study include aliphatic, halogen, nitrile, and acetamido functional groups. In addition, the isosteric replacement of the phenyl group by thiophene was evaluated. The anti-glioma activities of selected compounds were evaluated in vitro and compared to the lead compound 2.
- Krishnamurthy, Mathangi,Gurley, Steven,Moore II, Bob M.
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p. 6489 - 6500
(2008/12/21)
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- Facile methods for the separation of the cis- and trans-diastereomers of limonene 1,2-oxide and convenient routes to diequatorial and diaxial 1,2-diols
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Facile methods are described for accessing four diastereomerically pure products from the commercial mixture of limonene oxide. The use of either an aqueous mercury(II)-mediated or H+-catalysed hydration, afforded a kinetic separation of (+)-limonene oxide (cis- or trans-isomer could be respectively recovered) from the commercially available diastereomeric mixture in good recovery yields and high diastereoselectivity (>98% de). The hydrolysed limonene oxide products, either trans-diequatorial or trans-diaxial diols, are also formed in good conversion yields and high diastereoselectivity (>98% de). Georg Thieme Verlag Stuttgart.
- Blair, Michael,Andrews, Philip C.,Fraser, Benjamin H.,Forsyth, Craig M.,Junk, Peter C.,Massi, Massimiliano,Tuck, Kellie L.
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p. 1523 - 1527
(2008/02/08)
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- Alternating copolymerization of limonene oxide and carbon dioxide
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The alternating copolymerization of (R)- or (S)-limonene oxide and CO2 using β-diiminate zinc acetate catalysts is reported. At 100 psi CO2 and 25 °C, the catalyst exhibits a high selectivity for the trans isomer and produces regioregular polycarbonate. The copolymer contains >99% carbonate linkages, a narrow molecular weight distribution, and an Mn value consistent with the [epoxide]/[Zn] ratio. Copyright
- Byrne, Christopher M.,Allen, Scott D.,Lobkovsky, Emil B.,Coates, Geoffrey W.
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p. 11404 - 11405
(2007/10/03)
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- Activation of hydrogen peroxide through hydrogen-bonding interaction with acidic alcohols: Epoxidation of alkenes in phenol
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(Matrix presented) Electrophilic activation of hydrogen peroxide can be achieved in acidic alcohol solvents without the need for a metal catalyst. This concept is illustrated by the epoxidation of alkenes with H2O 2 employing phenol as a solvent. It is proposed that intermolecular hydrogen bonding between H2O2 and phenol activates H 2O2 for oxygen-atom transfer. In this interaction, the role of phenol is purely catalytic.
- Wahlen, Joos,De Vos, Dirk E.,Jacobs, Pierre A.
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p. 1777 - 1780
(2007/10/03)
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- A facile and efficient method for the kinetic separation of commercially available cis- and trans-limonene epoxide
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cis- and trans-Diastereomers of (R)-(+)-limonene oxide can be purified by simple kinetic separation of the commercially available (1:1) diastereomeric mixture of limonene oxides. Nucleophilic amines, such as pyrrolidine and piperidine, selectively open the epoxide ring of the trans-isomer, leaving the cis-limonene oxide largely unreacted. The unreacted cis-(R)-limonene oxide is recovered in up to 88% yield. On the other hand, less nucleophilic amines, such as triazole or pyrazole, selectively catalyze hydrolysis of the cis-limonene oxide to 1,2-limonene diol leaving the trans-limonene oxide largely unreacted. The unreacted trans-limonene oxide is recovered in up to 80% of the theoretical yield by a simple workup procedure. The cis- and trans-diastereomers of (R)-(+)-limonene oxide thus isolated were found to be >98% pure by both GC and NMR analyses. Thus, depending on the choice of amine, either cis- or trans-limonene oxide may be obtained in high diastereomeric purity by this simple and environmentally friendly method.
- Steiner, Derek,Ivison, Lacie,Goralski, Christian T,Appell, Robert B,Gojkovic, Jasna R,Singaram, Bakthan
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p. 2359 - 2363
(2007/10/03)
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- Modelling the biokinetic resolution of diastereomers present in unequal initial amounts
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The enantiomeric ratio (E) is commonly used to evaluate enzyme-catalysed kinetic resolutions. Chen et al. (1982) proposed a model for the enantiomeric ratio, which relates the extent of substrate conversion and the enantiomeric excess. The model, however,
- De Carvalho, Carla C.C.R.,Van Keulen, Frederik,Da Fonseca, M.Manuela R.
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p. 1637 - 1643
(2007/10/03)
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- Resolution of limonene 1,2-epoxide diastereomers by mercury(II) ions
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When HgCl2 was added to a diastereomeric mixture of cis- and trans-(4S)-limonene 1,2-epoxide, the Hg(II) ions stereoselectively complexed to the cis epoxide, enabling ring opening by water. The resulting mercuric salt could be demetalated by treatment with NaBH4, giving a mixture of diastereomeric (1S,2S,4S)- and (1R,2R,4S)-diols. The remaining trans-(4S)-epoxide was obtained in >98% d.e. and 40% yield. For reactions on a larger scale, the most convenient reaction system was Hg(OAc)2 in 50% acetone/tris-HCl buffer pH 7.0. The reaction rate was affected by the pH, with pH 6-8 as optimum.
- Van der Werf, Mari?t J.,Jongejan, Hugo,Franssen, Maurice C.R.
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p. 5521 - 5524
(2007/10/03)
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- Reactions of cis-and trans-epoxy derivatives of (+)-3-carene and limonene with aldehydes over askanite-bentonite clay
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cis-and trans-Epoxy derivatives of (+)-3-carene, limonene, and dipentene react with aldehydes in the presence of askanite-bentonite clay to give acetals. Hydrolysis of the latter selectively yields the corresponding cis-diols. The relative contribution of intra-and intermolecular processes in the reactions of epoxy derivatives with aldehydes is determined mainly by steric factor. * This study was financially supported by the Russian Foundation for Basic Research (project no. 97-03-32 952a).
- Volcho,Tatarova,Korchagina,Salakhutdinov,Barkhash
-
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- Catalytic transformation of (+) - Limonene oxide over binary oxide catalysts of alumina-rare earths
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The transformation reactions of (+)-limonene oxide over binary oxides like Al2O3-Y2O3, Al2O3- Sm2O3, Al2O3-Eu2O3, Al2O3-Pr6O11 and Al2O3-Nd2O3 at 110°C and 140°C are discussed. The activity of single oxides like Al2O3, Eu2O3, Nd2O3 and Y2O3 used for the transformation reaction is studied at 110°C. Among the binary oxides, Al2O3-Eu2O3 show maximum activity for epoxide transformation. Methyl (3-isopropenyl cyclopentyl) ketone (4) and carvone (5) are the major products formed over binary oxides at higher reaction temperture.
- Jayasree,Narayanan
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- Facile Formation of trans-Cyclohexanediols by the Aerobic Oxidation of Cyclohexenes with Sodium Disulfite
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Disulfite was found to be an excellent oxidizing reagent for a gentle and stereoselective reaction to produce trans-diols via corresponding epoxides from the cyclohexenes, such as 1-p-menthen-8-yl acetate, 1,8-p-menthadiene, and 2-pinene.
- Kimbara, Nagashige,Izumi, Shunsuke,Hirata, Toshifumi
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p. 1198 - 1200
(2007/10/02)
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- BIOTRANSFORMATION OF LIMONENE AND RELATED COMPOUNDS BY ASPERGILLUS CELLULOSAE
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The biotransformation of (+)-, (-)- and (+/-)-limones by Aspergillus cellulosae M-77 has been investigated. (+)-Limonene was transformed mainly to (+)-isopiperperitenone, (+)-limonene-1,2-trans-diol, (+)-cis-carveol and (+)-perilly alcohol, along with the minor formation of isopiperitenol and α-terpineol, whereas (-)-limonene was transformed to (-)-perillyl alcohol, (-)-limonene-1,2-trans-diol and (+)-neodihydrocarveol as the major products, along with the minor products such as (-)-isopiperitenone.In the case of the DL-form, perillyl alcohol, limonene-trans-1,2-diol, isopiperitenone and α-terpineol were also formed. 1-Methylcyclohexene and cyclohexene were also transformed to 3-methyl-2-cyclohexenone and 2-cyclohexenone via the corresponding alcohols, respectively.Key Word Index: Aspergillus cellulosae; biotransformation; (+)-, (-)- and (+/-)-limones; isoperitenone; limonene-1,2-trans-diol; cis-carveol; α-terpineol; 1-methylcyclohexene; cyclohexene; 3-methyl-2-cyclohexenone; 2-cyclohexenone.
- Noma, Yoshiaki,Yamasaki, Sumika,Asakawa, Yoshinori
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p. 2725 - 2728
(2007/10/02)
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- Cobalt mediated cyclisations of epoxy olefins
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Irradiation of solutions of β-hydroxycobaloximes e.g. (2), (5), (9) and (13) derived from epoxy olefins [e.g. (1), (8) and (12)] and cobalt(I) dimethylglyoxime, using a sunlamp at room temperature, leads to facile cyclisation producing cycloalkanols e.g. (4), (6), (10) and (14). By contrast, only the products viz (3), (7) and (11) of dehydrocobaltation are produced when the same β-hydroxycobaloximes are heated under reflux in benzene.
- Harrowven,Pattenden
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p. 243 - 246
(2007/10/02)
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- INTERCONVERSION AND CYCLIZATION OF ACYCLIC ALLYLIC PYROPHOSPHATES IN THE BIOSYNTHESIS OF CYCLIC MONOTERPENOIDS IN HIGHER PLANTS
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Key Word Index - Biosynthesis; interconversion; cyclization; acyclic allylic pyrophosphates; cyclic monoterpenoids; higher plants.The biosynthesis of cyclic monoterpenoids has been investigated in both intact plants and cell-free extracts of several higher plants.The participation of a non-redox process in the biosynthesis of the cyclic monoterpenoids was indicated by the retention of all the tritium labels originating from mevalonic acid and geranyl, neryl and linalyl pyrophosphates.The cell-free extract catalysed the non-redox interconversions of geranyl, neryl and linalyl pyrophosphates to each other.By contrast, in both intact plants and cell-free extracts, the incorporation of linalyl pyrophosphate into the cyclic monoterpenoids occurred preferentially to the incorporation of neryl and geranyl pyrophosphates.These observations suggest the involvetment of a teriary allylic compound and/or its equivalent as a key intermediate, not only in the interconversion of the acyclic allylic pyrophosphates, but also in the formation of the cyclic monoterpenoids.
- Suga, Takayuki,Hirata, Toshifumi,Aoki, Tadashi,Shishibori, Tsuyoshi
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p. 2769 - 2776
(2007/10/02)
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