13040-03-4Relevant articles and documents
Practical method for increasing optical purity of cis-verbenol
Kovalenko, Vitaly,Krauchanka, Aliaksei,Prokhorevich, Konstantin
, p. 865 - 869 (2019)
R/S mixture of monoterpene alcohol cis-verbenol can be separated in preparative scale by its conversion into phthalic mono-ester and subsequent crystallization of its diastereomeric salts with (R)-α-methylbenzylamine and (S)-α-methylbenzylamine. Finally, basic methanolysis of the resolved phthalic mono-esters results (S)-cis-verbenol and (R)-cis-verbenol in high enantiomeric and diastereomeric purity.
Heterogeneous selective oxidation catalysts based on coordination polymer MIL-101 and transition metal-substituted polyoxometalates
Maksimchuk,Timofeeva,Melgunov,Shmakov,Chesalov,Dybtsev,Fedin,Kholdeeva
, p. 315 - 323 (2008)
Titanium- and cobalt-monosubstituted Keggin heteropolyanions, [PW11CoO39]5- and [PW11TiO40]5-, were electrostatically bound to the chromium terephthalate polymer matrix MIL-101. The MIL-supported polyoxometalate (POM) catalysts were characterized by elemental analysis, XRD, N2 adsorption, and FT-IR-spectroscopy. The catalytic performance of both MIL-101 and the novel composite materials M-POM/MIL-101 was assessed in the oxidation of three representative alkenes-α-pinene, caryophyllene, and cyclohexene-using molecular oxygen and aqueous hydrogen peroxide as oxidants. Ti-POM/MIL-101 demonstrated fairly good catalytic activity and selectivity in α-pinene allylic oxidation and caryophyllene epoxidation with hydrogen peroxide, whereas Co-POM/MIL-101 catalyzed α-pinene allylic oxidation by molecular oxygen. Both composite materials are stable to POM leaching, behave as true heterogeneous catalysts, and can be used repeatedly without sustaining a loss of activity and selectivity in oxidations with O2 and H2O2, provided that rather mild reaction conditions (T 2O2] 0.2 M) are used with the latter oxidant.
Photokatalytische Oxygenierung von Cycloalkenen mit Mangan(III) Tetraarylporphyrin-Komplexen
Weber, L.,Behling, J.,Haufe, G.,Hennig, H.
, p. 265 - 268 (1992)
The catalytic oxygenation of cyclohexene, 1-methylcyclohexene, α-pinene, 1,5-dimethylcycloocta-1,5-diene, and cis,trans-cyclodeca-1,5-diene with (tetraarylporphyrinato)manganese(III) complexes in the presence of molecular oxygen and visible light is reported.The photocatalytic reaction results in the formation of epoxides and allylic oxygenation products due to allylic hydrogen abstraction.
Engineering the haem monooxygenase cytochrome P450cam for monoterpene oxidation
Bell,Sowden,Wong
, p. 635 - 636 (2001)
Monooxygenated terpenes are fine fragrance and flavouring chemicals, and active site mutants of the haem monooxygenase cytochrome P450cam which were designed to have improved complementarity between the substrate binding pocket and the monoterp
Biomass toward fine chemical products: Oxidation of α-pinene over sieves nanostructured modified with vanadium
Cánepa, Analía L.,Chanquía, Corina M.,Vaschetti, Virginia M.,Eimer, Griselda A.,Casuscelli, Sandra G.
, p. 65 - 73 (2015)
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.
H2O2 based α-pinene oxidation over Ti-MCM-41. A kinetic study
Cánepa, Analía L.,Herrero, Eduardo R.,Crivello, Mónica E.,Eimer, Griselda A.,Casuscelli, Sandra G.
, p. 1 - 7 (2011)
α-Pinene oxidation with hydrogen peroxide using Ti-MCM-41, prepared by hydrothermal synthesis, with a Ti content of 1.12 wt.% was studied. The major products of reaction observed were: verbenone, verbenol and campholenic aldehyde which are used in the pha
Aerobic oxidations of α-pinene over cobalt-substituted polyoxometalate supported on amino-modified mesoporous silicates
Maksimchuk,Melgunov,Chesalov,Mrowiec-Bialon,Jarzebski,Kholdeeva
, p. 241 - 248 (2007)
Co-containing polyoxometalate [Bu4N]4H[PW11Co(H2O)O39] (Co-POM) was supported on various NH2-modified mesoporous silicate matrixes (SBA-15, MCF, and SiO2-xerogel). The catalysts
Kinetic study of α-pinene allylic oxidation over FePcCl16-NH2-SiO2 catalyst
Becerra, Jaime-Andrés,González, Lina-María,Villa, Aída-Luz
, p. 12 - 21 (2016)
The kinetic of α-pinene oxidation over an iron hexadecachlorinated phthalocyanine immobilized on modified silica (FePcCl16-NH2-SiO2) with t-butyl hydroperoxide (TBHP) as oxidant is proposed. Reaction rates were calculated by the initial reaction rate method from the data obtained in a batch reactor, and compared with kinetic expressions proposed from mechanisms based on Langmuir Hinshelwood Hougen Watson (LHHW) and power-rate law models. The kinetic parameters were estimated from the experimental data by optimization using the Genetic Algorithm. A kinetic expression based on LHHW model with the adsorption of α-pinene, TBHP and the main reaction products (verbenone, α-pinene epoxide and verbenol) on the surface of the catalyst predicted the experimental data with good accuracy (R2?=?0.986). The apparent activation energy of α-pinene allylic oxidation over FePcCl16-NH2-SiO2/TBHP was 40.08?kJ/mol. α-Pinene conversion of 83.7% was obtained after 23?h with a selectivity to verbenone of 23%. Under the reaction conditions leaching of the active species was not observed; however, the effect of radicals in the bulk liquid phase was demonstrated, confirming that the reaction involves a combination of both heterogeneous and homogeneous pathways. The catalyst can be used at least in seven cycles without loss of α-pinene conversion nor verbenone selectivity.
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Regan
, p. 3801,3804 (1969)
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Molecular recognition in (+)-α-pinene oxidation by cytochrome P450cam
Bell, Stephen G.,Chen, Xuehui,Sowden, Rebecca J.,Xu, Feng,Williams, Jennifer N.,Wong, Luet-Lok,Rao, Zihe
, p. 705 - 714 (2003)
Oxygenated derivatives of the monoterpene (+)-α-pinene are found in plant essential oils and used as fragrances and flavorings. (+)-α-Pinene is structurally related to (+)-camphor, the natural substrate of the heme monooxygenase cytochrome P450cam from Pseudomonas putida. The aim of the present work was to apply the current understanding of P450 substrate binding and catalysis to engineer P450cam for the selective oxidation of (+)-α-pinene. Consideration of the structures of (+)-camphor and (+)-α-pinene lead to active-site mutants containing combinations of the Y96F, F87A, F87L, F87W, and V247L mutations. All mutants showed greatly enhanced binding and rate of oxidation of (+)-α-pinene. Some mutants had tighter (+)-α-pinene binding than camphor binding by the wild-type. The most active was the Y96F/V247L mutant, with a (+)-α-pinene oxidation rate of 270 nmol (nmol of P450cam)-1 min-1, which was 70% of the rate of camphor oxidation by wild-type P450cam. Camphor is oxidized by wild-type P450cam exclusively to 5-exo-hydroxycamphor. If the gem dimethyl groups of (+)-α-pinene occupied similar positions to those found for camphor in the wild-type structure, (+)-cis-verbenol would be the dominant product. All P450cam enzymes studied gave (+)-cis-verbenol as the major product but with much reduced selectivity compared to camphor oxidation by the wild-type. (+)-Verbenone, (+)-myrtenol, and the (+)-α-pinene epoxides were among the minor products. The crystal structure of the Y96F/F87W/V247L mutant, the most selective of the P450cam mutants initially examined, was determined to provide further insight into P450cam substrate binding and catalysis. (+)-α-Pinene was bound in two orientations which were related by rotation of the molecule. One orientation was similar to that of camphor in the wild-type enzyme while the other was significantly different. Analysis of the enzyme/substrate contacts suggested rationalizations of the product distribution. In particular competition rather than cooperativity between the F87W and V247L mutations and substrate movement during catalysis were proposed to be major factors. The crystal structure lead to the introduction of the L244A mutation to increase the selectivity of pinene oxidation by further biasing the binding orientation toward that of camphor in the wild-type structure. The F87W/Y96F/L244A mutant gave 86% (+)-cis-verbenol and 5% (+)-verbenone. The Y96F/L244A/V247L mutant gave 55% (+)-cis-verbenol but interestingly also 32% (+)-verbenone, suggesting that it may be possible to engineer a P450cam mutant that could oxidize (+)-α-pinene directly to (+)-verbenone. Verbenol, verbenone, and myrtenol are naturally occurring plant fragrance and flavorings. The preparation of these compounds by selective enzymatic oxidation of (+)-α-pinene, which is readily available in large quantities, could have applications in synthesis. The results also show that the protein engineering of P450cam for high selectivity of substrate oxidation is more difficult than achieving high substrate turnover rates because of the subtle and dynamic nature of enzyme - substrate interactions.
Individual stereoisomers of verbenol and verbenone express bioactive features
Ivanov, Marija,Kovalenko, Vitaly,Svirid, Anastasia,Kosti?, Marina,Petrovi?, Jovana,Stojkovi?, Dejan
, (2021/12/13)
Naturally occurring terpene core compounds have been used extensively in both pharmaceutical and cosmetic industry. However, since chirality of these compounds has profound influence on the level of their bioactivity, the aim of the present study was to a
Stereospecific synthesis of S-(?)-trans-verbenol and its antipode by inversion of sterically hindered alcohols
Fang, Jia-Xing,Kong, Xiang-Bo,Liu, Fu,Zhang, Su-Fang,Zhang, Zhen
, (2020/12/15)
S-(?)-trans-Verbenol (1) and its antipode, R-(+)-trans-verbenol (1′) have been confirmed as the critical pheromone components of bark beetles. Synthesis of these two active secondary alcohols (1 and 1′) from commercially available starting materials S-α-pinene and R-α-pinene was reported. The key steps were mainly depended on the effective SN2 stereo-inversion of the hydroxy group of sterically hindered alcohols (3 and 3′), using Mitsunobu reaction or hydrolysis of mesylate ester, alternatively. Our results provide a new and stereo-selectivity way to obtain optically active insect pheromones.
