- Development of rapid and selective epoxidation of α-pinene using single-step addition of H2O2in an organic solvent-free process
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This study reports substantial improvement in the process for oxidising α-pinene, using environmentally friendly H2O2 at high atom economy (~93%) and selectivity to α-pinene oxide (100%). The epoxidation of α-pinene with H2O2 was catalysed by tungsten-based polyoxometalates without any solvent. The variables in the screening parameters were temperatures (30-70 °C), oxidant amount (100-200 mol%), acid concentrations (0.02-0.09 M) and solvent types (i.e., 1,2-dichloroethane, toluene, p-cymene and acetonitrile). Screening the process parameters revealed that almost 100% selective epoxidation of α-pinene to α-pinene oxide was possible with negligible side product formation within a short reaction time (~20 min), using process conditions of a 50 °C temperature in the absence of solvent and α-pinene/H2O2/catalyst molar ratio of 5?:?1?:?0.01. A kinetic investigation showed that the reaction was first-order for α-pinene and catalyst concentration, and a fractional order (~0.5) for H2O2 concentration. The activation energy (Ea) for the epoxidation of α-pinene was ~35 kJ mol-1. The advantages of the epoxidation reported here are that the reaction could be performed isothermally in an organic solvent-free environment to enhance the reaction rate, achieving nearly 100% selectivity to α-pinene oxide.
- Eze, Valentine C.,Harvey, Adam P.,López Fernández, Ana María,Mukhtar Gunam Resul, Mohamad Faiz,Rehman, Abdul
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p. 33027 - 33035
(2021/12/07)
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- Biomimetic conversion of α-pinene with H2O2 to sobrerol over V2O5: Dihydroxylation by a peroxo vanadium peracid vectoring gentle synergistic oxidation
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In this communication, we report the gentle preparation of sobrerol from dihydroxylation of α-pinene synergistically catalyzed by V2O5-H2O2 under benign conditions. It was proposed that a “peroxo vanadium acid”, VVO(OH)(OOH), was formed by HOO? insertion and proton transfer between V2O5 and H2O2. Theoretical DFT calculations that using the dimer?vanadium peracid as a model of the catalytically active species revealed that peroxo vanadium acid exhibited bifunctional catalytic capabilities resembling epoxidation of α-pinene by peracetic acid and then open-ring hydration with an acetic media.
- He, Huiting,Huang, Geng,Kirk, Steven Robert,Li, Hui,Liu, Jian,Liu, Qiang,Liu, Xianxiang,Mao, Liqiu,Su, Shengpei,Xu, Qiong,Yin, Dulin
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- Tailoring chemoenzymatic oxidation: Via in situ peracids
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Epoxidation chemistry often suffers from the challenging handling of peracids and thus requires in situ preparation. Here, we describe a two-phase enzymatic system that allows the effective generation of peracids and directly translate their activity to the epoxidation of olefins. We demonstrate the approach by application to lipid and olefin epoxidation as well as sulfide oxidation. These methods offer useful applications to synthetic modifications and scalable green processes.
- Re, Rebecca N.,Proessdorf, Johanna C.,La Clair, James J.,Subileau, Maeva,Burkart, Michael D.
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supporting information
p. 9418 - 9424
(2019/11/14)
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- Synthesis of Fencholenic Aldehyde from α-pinene Epoxide on Modified Clays
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The conditions for isomerization of α-pinene epoxide (2,3-epoxypinane) on modified clays that gave comparatively high contents (33.0%) of fencholenic (iso-campholenic) aldehyde in the product mixture were determined. An effective method for isolating it w
- Sidorenko, A. Yu.,Ignatovich, Zh. V.,Ermolinskaya,Kravtsova,Baranovskii,Koroleva,Agabekov
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p. 893 - 897
(2018/09/27)
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- Biomass toward fine chemical products: Oxidation of α-pinene over sieves nanostructured modified with vanadium
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Vanadium-containing molecular sieves (V-M(x)) were synthetized and applied as heterogeneous catalysts for the liquid phase oxidation of α-pinene with hydrogen peroxide at 70°C. It has been found that the vanadium content in V-M(x) materials affected the conversion of α-pinene and product distribution. The turnover numbers increased strongly with the decreasing of V content probably caused by a high V dispersion. The major products were verbenone, trans-sobrerol and campholenic aldehyde. The acid-base properties of V-M(x) affected the distribution of products formed via the isomerization of α-pinene oxide over Lewis acid sites to campholenic aldehyde while Br?nsted acid sites brought about the formation of 1,2 pinanediol and trans-sobrerol by hydrolysis and by the opening of oxirane ring. The increase in V content in V-M(x) led to the increase in campholenic aldehyde, 1,2 pinanediol, trans- sobrerol and over oxidation products. Moreover, the effect of several solvents on the reaction oxidation was studied. The results showed that the highest α-pinene conversions are obtained in the following order: acetonitrile > ethanol > isoamyl alcohol > methyl ethyl ketone. Thus, using aprotic solvents, the catalytic activity was increased and the formation of alkyl glycol ethers as by-product was not observed.
- Cánepa, Analía L.,Chanquía, Corina M.,Vaschetti, Virginia M.,Eimer, Griselda A.,Casuscelli, Sandra G.
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- Effect of iron content on selectivity in isomerization of α-pinene oxide to campholenic aldehyde over Fe-MMM-2 and Fe-VSB-5
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Isomerization of α-pinene oxide to campholenic aldehyde (CA) was investigated over Fe-containing mesoporous mesophase materials (Fe-MMM-2) and microporous nickel phosphate molecular sieves (Fe-VSB-5). Activity and selectivity of reaction towards CA over Fe-containing materials was found to depend on iron content in materials that affects oligomeric state of Fe and amount of Lewis acid sites. In the presence of Fe-VSB-5 selectivity towards CA increased with increase in iron content in structure, while that decreased in the presence of Fe-MMM-2. This phenomenon is related to change in agglomeration of iron species in Fe-MMM-2 structure. The high selectivity towards CA in the presence of Fe-VSB-5 was suggested to arise from unique structure of these materials, which favours shape selectivity.
- Timofeeva,Panchenko,Hasan, Zubair,Khan, Nazmul Abedin,Mel'Gunov,Abel,Matrosova,Volcho,Jhung, Sung Hwa
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p. 427 - 433
(2013/11/19)
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- Hot water-promoted SN1 solvolysis reactions of allylic and benzylic alcohols
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During the studies of hydrolysis of epoxides in water, we found that the hydrolysis of (-)-α-pinene oxide at 20 °C gave enantiomerically pure trans-(-)-sobrerol, whereas the same reaction in water heated at reflux unexpectedly gave a racemic mixture of trans- and cis-sobrerol (trans/cis=6:4). We have examined this remarkable difference in detail and found that hot water, whose behavior is quite different compared with room- or high-temperature water, could promote SN1 solvolysis reactions of allylic alcohols and thus caused the racemization of trans-(-)-sobrerol. The effect of reaction temperature, the addition of organic co-solvent, and the concentration of the solute on the rate of the racemization of trans-(-)-sobrerol were further examined to understand the role that hot water played in the reaction. It was proposed that the catalytic effects of hot water are owing to its mild acidic characteristic, thermal activation, high ionizing power, and better solubility of organic reactant. Further investigation showed that the racemization of other chiral allylic/benzylic alcohols could efficiently proceed in hot water.
- Xu, Zhao-Bing,Qu, Jin
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supporting information
p. 314 - 323
(2013/03/13)
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- Unique salt effect on highly selective synthesis of acid-labile terpene and styrene oxides with a tungsten/Hcatalytic system under acidic aqueous conditions
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Acid-labile epoxides such as terpene and styrene oxides are effectively synthesized in high yields with good selectivities using tungsten-catalyzed hydrogen peroxide epoxidation in the presence of NaO The salt effect is thought to originate with the addition of a saturated amount of NaOto aqueous H this addition strongly inhibited the undesired hydrolysis of the acid-labile epoxy products, despite the biphasic conditions of substrate as oil phase and Has acidic aqueous phase.
- Hachiya, Houjin,Kon, Yoshihiro,Ono, Yutaka,Takumi, Kiyoshi,Sasagawa, Naoki,Ezaki, Yoichiro,Sato, Kazuhiko
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experimental part
p. 1672 - 1678
(2012/07/16)
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- Unique salt effect on the high yield synthesis of acid-labile terpene oxides using hydrogen peroxide under acidic aqueous conditions
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Acid-labile epoxides such as -pinene oxide are (effectively) synthesized in high yield from the epoxidation of terpenes with aqueous H2O 2 catalyzed by Na2WO4, [Me(n-C 8H17)3N]HSO4, and PhP(O)(OH) 2 in the presence of Na2SO4 as an auxiliary additive under organic solvent-free conditions at ambient temperature. Origin of the salt effect is considered that the addition of a saturated amount of Na2SO4 to aqueous H2O2 strongly inhibited the undesired hydrolysis of the acid-labile epoxide products, despite the highly acidic reaction conditions. Georg Thieme Verlag Stuttgart · New York.
- Hachiya, Houjin,Kon, Yoshihiro,Ono, Yutaka,Takumi, Kiyoshi,Sasagawa, Naoki,Ezaki, Yoichiro,Sato, Kazuhiko
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scheme or table
p. 2819 - 2822
(2012/01/02)
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- Myrseguinosides A-E, five new glycosides from the fruits of Myrsine seguinii
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Chemical investigation of the 1-BuOH soluble fraction of the dried fruits of Myrsine seguinii (Myrsinaceae) led to the isolation of five new glycosides, named myrseguinosides A-E (1-5), together with eight known compounds (6-13). The absolute structures of the new glycosides were elucidated by spectroscopic and chemical analyses to be a monoterpene glucoside (1), two flavonol glycosides (2, 3), and two oleanane-type triterpene saponins (4, 5). Myrseguinosides B (2), D (4), and E (5) exhibited 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and growth inhibitory activity toward human cancer cells, respectively.
- Matsunami, Katsuyoshi,Otsuka, Hideaki,Takeda, Yoshio
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experimental part
p. 1274 - 1280
(2011/12/04)
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- Formation of trans-verbenol and verbenone from α-pinene catalysed by immobilised Picea abies cells
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Both enantiomers and the raceinate of α-pinene were transformed by Picea abies cells immobilised on alginate. The main products were cis- and trans-verbenol, the later being further transformed to verbenone. The enantiomeric purity of each product more or less corresponded to that of the substrate. Transformation by free cells was faster than that by the immobilised cells. The ratio of products differed to some extent between the transformation by tree and immobilised cells.
- Vanek, Tomas,Halik, Jan,Vankova, Radmila,Valterova, Irena
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p. 321 - 325
(2007/10/03)
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- A convenient, large scale synthesis of trans-(+)-sobrerol
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A convenient and highly efficient synthesis of optically pure trans(+)-sobrerol (1), starting from methyl 3,5-dihydroxy-4-methyl benzoate 2 in 8 steps with overall yield 26%, is reported. The key intermediate 4 is prepared in remarkably high yield by selectively esterification of 3 using lipase as catalyst. A critical step to stereoselectively inverse the configuration of 7 is realized under Mistunobu conditions.
- Wang, Qiuan,Li, Yanlin,Chen, Qingqi
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p. 2125 - 2134
(2007/10/03)
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- Partial purification of Nigella sativa L. seed lipase and its application in transesterification reactions
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Nigella sativa L. seed lipase isolated from defatted seeds was partially purified and used as catalyst in transesterification reactions. Purification of an ammonium sulfate-precipitated sample (at 35% saturation, Nigella PL) by DEAE ion-exchange chromatography increased the specific activity from 13.9 to 156.7 U/mg protein. Nigella PL and Nigella CPL (the partially purified enzyme sample obtained by DEAE ion-exchange chromatography) catalyzed the transesterification of vinyl acetate with octanol, with racemic sulcatol (6-methyl-5-hepten-2-ol), and with racemic trans-sobrerol (trans-p-menth-6-ene-2,8-diol) in different organic solvents. Both activity and enantioselectivity of the enzyme samples used for these biotransformations were affected by the nature of the organic solvent.
- Tuter, Melek,Secundo, Francesco,Riva, Sergio,Ayse Aksoy,Ustun, Guldem
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- Comparative autoxidation of 3-Carene and α-Pinene: Factors governing regioselective hydrogen abstraction reactions
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Autoxidation reactions of 3-Carene 1 and α-Pinene 2 were performed using various homogeneous catalysts. Different product and regio- selectivities were observed. The factors that promote hydrogen abstraction (HA) reactions in both molecules are discussed, and it is proposed that the difference in the product selectivities is due to the lack of 'cyclic activation' in 2. Oxidation of 1 produced mainly 3-carene-5-one 3, while 2 yielded 2,3-epoxypinane 6 as the major product.
- Rothenberg, Gadi,Yatziv, Yael,Sasson, Yoel
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p. 593 - 598
(2007/10/03)
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- Resolution of (±)-trans-sobrerol by lipase PS-catalyzed transesterification and effects of organic solvents on enantioselectivity
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Resolution of the mucolytic drug (±)-trans-sobrerol (1) was achieved by transesterification with vinyl acetate in organic media, catalyzed by free or immobilized Lipase PS. The enantioselectivity of the enzyme was markedly influenced by the nature of the organic solvent, but there was no correlation between enantiomeric ratio values (70-500) and either the hydrophobicity or the dielectric constant of the medium. With the enzyme immobilized onto Hyflo Super Cell and t-amyl alcohol as the solvent, the selectivity of Lipase PS for (-)-1 was extremely high and, at 50% conversion both (-)-trans-sobrerol and (+)-trans-sobrerol monoacetate were obtained in practically 100% optical purity.
- Bovara,Carrea,Ferrara,Riva
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p. 931 - 938
(2007/10/02)
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- Pheromone Synthesis, CIV.- Synthesis of the Enantiomers of α-Phellandren-8-ol (p-Mentha-1,5-dien-8-ol), a Monoterpene from Bark Beetles
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Enantiomerically pure (R)-α-phellandren-8-ol (p-mentha-1,5-dien-8-ol, 1a) was synthesized from (R)-carvone (2).Similarly (S)-1a was synthesized from (S)-2.
- Mori, Kenji,Igarashi, Yasuhiro
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- Stereocontrolled Regiospecificity of the Water Loss from trans-Sobrerol Radical Cation upon Electron Ionization
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Water loss from trans-sobrerol upon electron impact ionization selectively involves the tertiary OH group, predominantly occuring by a stereocontrolled H-transfer from C(5) position in a rate-determining step process, as proved by 18O and deuterium labelling.Monomethyl ethers behave accordingly.Ionic structures of the water-loss product or products are investigated by metastable ion and collision activation mass-analysed ion kinetic energy spectroscopy, using model ions generated from some substrates, which are chemically related to trans-sobrerol in condensed phase, i.e. α-pinane epoxide, cis-sobrerol and pinol.A substantial conversion of cis-sobrerol molecular ions to ionized pinol by loss of water has been demonstrated.
- Selva, Antonio,Ferrario, Francesco,Ventura, Paolo,Pellegata, Renato
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p. 523 - 529
(2007/10/02)
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- THE ENANTIOSELECTIVE BIOTRANSFORMATION OF α-TERPINEOL AND ITS ACETATE WITH THE CULTURED CELLS OF NICOTIANA TABACUM
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In the biotransformation of the enantiomers of p-ment-1-en-8-ol (α-terpineol) and 8-acetoxy-p-ment-1-ene (α-terpinyl acetate) with the cultured suspension cells of Nicotina tabacum, it was clarified that the cultured cells effected the hydroxylation at the 6-position of (4R)-(+)-enantiomer in preference to the (4S)-(-)-enantiomer, whereas the cells did the hydrolysis of the acetoxyl group and the hydroxylation of the ethylenic linkage of (4S)-(-)-α-terpinyl acetate in preference to the (4R)-(+)-enantiomer.
- Suga, Takayuki,Hirata, Toshifumi,Lee, Ym Sook
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p. 1595 - 1598
(2007/10/02)
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- THE STEREOSPECIFIC HYDROXILATION OF ENDOCYCLIC ETHYLENIC LINKAGE IN THE BIOTRANSFORMATION OF α- TERPINYL ACETATE WITH CULTURED SUSPENSION CELLS OF NICOTIANA TABACUM
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The biotransformation of (+/-)-8-acetoxy-p-menth-1-ene (α-terpinyl acetate) with the cultured cells of Nicotiana tabacum was found to result in the predominant formation of 8-acetoxy-c-4-p-menthane-r-1, t-2-diol.This experimental result indicates that the hydroxylation of the endocyclic ethylenic linkage with the cultured suspension cells is stereospecific.
- Hirata, Toshifumi,Lee, Ym Sook,Suga, Takayuki
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p. 671 - 674
(2007/10/02)
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