13040-03-4Relevant academic research and scientific papers
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.
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
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
, (2019)
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.
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.
Comparative autoxidation of 3-Carene and α-Pinene: Factors governing regioselective hydrogen abstraction reactions
Rothenberg, Gadi,Yatziv, Yael,Sasson, Yoel
, p. 593 - 598 (1998)
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.
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
Homogeneous and polymer-supported catalysts in the oxidation of α-pinene with oxygen
Men'shikov,Sennikov,Romanova,Sycheva,Ostroushko
, p. 790 - 794 (2004)
The catalytic activities of nitrogen-containing cobalt complexes, polymer (AN-251 anion exchanger)-supported cobalt complex, and a polymer-salt composition containing molybdenum salt and nonionogenic water-soluble polymers were compared in the oxidation o
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.
Hydrocarbon oxidation over Fe- and Cr-containing metal-organic frameworks MIL-100 and MIL-101-a comparative study
Kholdeeva, Oxana A.,Skobelev, Igor Y.,Ivanchikova, Irina D.,Kovalenko, Konstantin A.,Fedin, Vladimir P.,Sorokin, Alexander B.
, p. 54 - 61 (2014)
Catalytic properties of Fe- and Cr-based metal-organic frameworks (MOFs) MIL-100 and MIL-101 have been assessed in two liquid-phase reactions: solvent-free allylic oxidation of alkenes (cyclohexene, α- and β-pinenes) with molecular oxygen and oxidation of anthracene (AN) with tert-butyl hydroperoxide (TBHP). In the oxidation of alkenes, the product selectivity strongly depends on the nature of metal (Fe or Cr) but, for the same metal, only slightly differs for the MIL-100 and MIL-101 structures. The Fe-containing MOFs afford the formation of unsaturated alcohols while Cr-based MOFs give mainly unsaturated ketones. Both Cr-MIL-100 and Cr-MIL-101 favor decomposition of cyclohexenyl hydroperoxide to produce 2-cyclohexen-1-one with 67-69% selectivity. Stability toward destruction reduced in the order Cr-MIL-101, Cr-MIL-100 > Fe-MIL-100 > Fe-MIL-101. In the oxidation of anthracene over both Cr-MOFs and Fe-MIL-101, the selectivity toward 9,10-anthraquinone (AQ) attained 100% at 92-100% AN conversion. The turnover frequency (TOF) decreased in the order Cr-MIL-101 > Fe-MIL-101 > Cr-MIL-100 > Fe-MIL-100. Cr-MIL-101 revealed superior catalytic performance in terms of AN conversion, AQ selectivity and TOF. Nearly quantitative yield of AQ was obtained after 1.5 h at 100 °C in chlorobenzene as solvent. No leaching of active metal occurred under optimal reaction conditions and the MOFs could be recycled several times without deterioration of the catalytic properties.
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
