50727-94-1Relevant articles and documents
Oxidovanadium(IV) complexes of 3-hydroxy-4-pyrone and 3-hydroxy-4- pyridinone ligands: A new generation of homogeneous catalysts for the epoxidation of geraniol
Pereira, Clara,Leite, Andreia,Nunes, Ana,Rebelo, Susana L. H.,Rangel, Maria,Freire, Cristina
, p. 98 - 104 (2010)
A novel generation of homogeneous catalysts for the epoxidation of geraniol, in the presence of tert-butyl hydroperoxide oxidant is reported. Oxidovanadium(IV) complexes of 3-hydroxy-4-pyrone and 3-hydroxy-4-pyridinone ligands exhibit excellent activity and selectivity towards the 2,3-epoxygeraniol product, only differing in the reaction times and turnover frequencies. The pyrone based complexes are the most efficient catalysts showing performances similar to that of the well known oxidovanadium(IV) acetylacetonate catalyst. Graphical abstract: [Figure not available: see fulltext.]
SELECTIVE EPOXIDATION OF ALLYLIC ALCOHOLS WITH DIBUTYLTIN OXYPEROXYDE
Kanemoto, Shigekazu,Nonaka, Tsuyoshi,Oshima, Koichiro,Utimoto, Kiitiro,Nozaki, Hitosi
, p. 3387 - 3390 (1986)
Dibutyltin oxyperoxide derived from BuSnO and tBuOOH epoxidize allylic alcohols with high stereo- and regioselectivities.
Photo-Oxidation of 2-(2-Furyl)-1,3-Dicarbonyl Compounds
Antonioletti, R.,Bonadies, F.,Pesci, S.,Scettri, A.
, p. 3947 - 3948 (1992)
A very efficient photo-sensitized oxidation of 2-(2-furyl)-1,3-dicarbonyl compounds 1 afford directly hydroperoxides 2 in stereoselective way.Compounds 2, easily isolated, can be conveniently employed in a selective epoxidation of trisubstituted allylic alcohols by a Sharpless-type procedure.
STEREOSELECTIVE EPOXIDATION OF ALLYLIC ALCOHOLS AND DEHYDROGENATIVE OXIDATION OF SECONDARY ALCOHOLS BY MEANS OF t-BUTYL HYDROPEROXIDE AND ALUMINIUM REAGENTS.
Takai,Oshima,Nozaki
, p. 3791 - 3795 (1983)
Treatment of a solution of geraniol and (t-BuO)//3Al in benzene with t-BuOOH at 5 degree C gives (2R*, 3R*)-2,3-epoxy-3,7-dimethyl-6-octenyl acetate in 83% yield after acetylative workup. Eight allylic alcohols are converted to alpha , beta -epoxy alcohols in preparative yields. The epoxidation of secondary (E)-allylic alcohols shows opposite stereo-selectivities to t-BuOOH-VO(acac)//2 system. Asymmetric epoxidation with a chiral hydroxamic acid as a ligand gives unsatisfactory degrees of enantiomeric excess. The same system can also convert secondary alcohols into ketones in excellent yields, while primary ones react very slowly.
Palladium-catalyzed stereospecific epoxide-opening reaction of γ,δ-epoxy-α,β-unsaturated esters with boric acid leading to γ,δ-diol derivatives with double inversion of configuration
Yu, Xiao-Qiang,Hirai, Atsushi,Miyashita, Masaaki
, p. 764 - 765 (2004)
A new palladium-catalyzed epoxide-opening reaction of γ,δ- epoxy-α,β-unsaturated esters with boric acid has been developed, which proceeds stereospecifically giving rise to the corresponding γ,β-diol derivatives with double inversion of the configuration, i.e., with retention of configuration, in excellent yields. The new method provides a useful tool in organic synthesis including natural product synthesis. (Graph Presented).
Dysprosium-doped zinc tungstate nanospheres as highly efficient heterogeneous catalysts in green oxidation of terpenic alcohols with hydrogen peroxide
Batalha, Daniel Carreira,Mesquita Borges, Kellen Cristina,de Fátima Gon?alves, Rosana,de Matos Rodrigues, Murillo Henrique,Godinho, Mário Júnior,Fajardo, Humberto Vieira,de Oliveira Bruziquesi, Carlos Giovani,da Silva, Márcio José
, p. 6661 - 6670 (2021/04/22)
A green route to oxidize terpenic alcohols (nerol and geraniol) with H2O2over a solid catalyst was developed. The Dy-doped ZnWO4catalyst was synthesized by coprecipitation and microwave-assisted hydrothermal heating, containing different dysprosium loads. All the catalysts were characterized through infrared spectroscopy, powder X-ray diffraction, surface area and porosimetry, transmission electronic microscopy image, andn-butylamine potentiometric titration analyses. The influence of main reaction parameters such as temperature, the stoichiometry of reactants, loads, and catalyst nature was assessed. ZnWO42.0 mol% Dy was the most active catalyst achieving the highest conversion (98%) and epoxide selectivity (78%) in nerol oxidation. The reaction scope was extended to other terpenic alcohols (i.e., geraniol, borneol, and α-terpineol). The highest activity of ZnWO42.0 mol% Dy was assigned to the lower crystallite size, higher surface area and pore volume, higher acidity strength and the greatest dysprosium load.
Total Synthesis of Kadcoccinic Acid A Trimethyl Ester
Gholami, Hadi,Trost, Barry M.,Zell, Daniel,Zhang, Guoting
supporting information, p. 12286 - 12293 (2021/08/20)
The first total synthesis of the trimethyl ester of kadcoccinic acid A is described. The central structural element of our synthesis is a cyclopentenone motif that allows the assembly of the natural product skeleton. A gold(I)-catalyzed cyclization of an enynyl acetate led to efficient construction of the cyclopentenone scaffold. In this step, optimization studies revealed that the stereochemistry of the enynyl acetate dictates regioisomeric cyclopentenone formation. The synthesis further highlights an efficient copper-mediated conjugate addition, merged with a gold(I)-catalyzed Conia-ene reaction to connect the two fragments, thereby forging the D-ring of the natural product. The synthetic strategy reported herein can provide a general platform to access the skeleton of other members of this family of natural products.
Vanadium-doped sodium phosphomolybdate salts as catalysts in the terpene alcohols oxidation with hydrogen peroxide
Ferreira, Sukarno Olavo,Rodrigues, Alana Alves,Vilanculo, Castelo Bandane,da Silva, Márcio José,da Silva, Rene Chagas
, p. 24072 - 24085 (2021/07/29)
In this work, we have explored the catalytic activity of Keggin-type heteropolyanions PMo12?nVnO40(3+n)?(n= 0, 1, 2, or 3) in the form of sodium salts in green oxidation routes of terpene alcohols with hydrogen peroxide. Nerol was the model molecule selected to assess the impacts of the main reaction parameters, such as temperature, catalyst load, and stoichiometry of reactants. The impacts of the presence of vanadium at different proportions (i.e., V1, V2, and V3loads/per anion) in the structure of phosphomolybdate catalysts were assessed. All the catalysts were characterized by various techniques such as powder X-ray diffraction, attenuated diffuse reflectance infrared spectroscopy, ultraviolet-visible spectroscopy, thermogravimetric analysis, isotherms of adsorption-desorption of N2measurements of surface area, scanning electronic microscopy, energy-dispersive X-ray spectroscopy, andn-butylamine potentiometric titration. Among the catalysts assessed, Na4PMo11VO40was the most active and selective toward epoxides. The efficiency of this catalyst in the epoxidation of different terpene alcohols was investigated. Special attention was dedicated to correlating the composition and properties of the vanadium-doped phosphomolybdic catalysts with their catalytic activity.
Proton-accelerated Lewis acid catalysis for stereo- And regioselective isomerization of epoxides to allylic alcohols
Baba, Misako,Hayashi, Satoshi,Hirabe, Rina,Noji, Masahiro,Takanami, Toshikatsu
supporting information, p. 7104 - 7107 (2021/07/28)
The isomerization of epoxides to allylic alcohols was developedviaproton-accelerated Lewis acid catalysis. The addition oftBuOH as a proton source is the key to the efficient catalytic cycle. Trisubstituted epoxides, including enantioenriched derivatives, were selectively converted to secondary-allylic alcohols without loss of enantiopurity.
New heptacoordinate tungsten(II) complexes with α-diimine ligands in the catalytic oxidation of multifunctional olefins
Vasconcellos-Dias, Maria,Nunes, Carla D.,Félix, Vítor,Brand?o, Paula,Calhorda, Maria José
, (2021/02/26)
New tungsten(II) and molybdenum(II) heptacoordinate complexes [MX2(CO)3(LY)] (MXLy: M = W, Mo; X = Br, I; LY = C5H4NCY = N(CH2)2CH3 with Y = H (L1), Me (L2), Ph (L3)) were synthesized and characterized by spectroscopic techniques and elemental analysis. The two tungsten complexes WXL1 (X = Br, I) were also structurally characterized by single crystal X-ray diffraction. The metal coordination environment is in both a distorted capped octahedron. The complexes with L1 and L2 ligands were grafted in MCM-41, after functionalization of the ligands with a Si(OEt)3 group. The new materials were characterized by elemental analysis, N2 adsorption isotherms, 29Si MAS and 13C MAS NMR. The tungsten(II) complexes and materials were the first examples of this type reported. All complexes and materials were tested as homogeneous and heterogeneous catalysts in the oxidation of multifunctional olefins (cis-hex-3-en-1-ol, trans-hex-3-en-1-ol, geraniol, S-limonene, and 1-octene), with tert-butyl hydroperoxide (TBHP) as oxidant. The molybdenum(II) catalyst precursors are in general very active, reaching 99% conversion and 100% selectivity in the epoxidation of trans-hex-3-en-1-ol. Their performance is comparable with that of the [Mo(η3-C3H5)X(CO)2(LY)] complexes, but it increases with immobilization. On the other hand, most of the W(II) complexes display an activity similar or inferior to that of the Mo(II) analogues and it decreases after they are supported in MCM-41. DFT calculations show that tungsten complexes and iodide ligands are more easily oxidized from M(II) to M(VI) than molybdenum ones, while the energies of relevant species in the catalytic cycle are very similar for all complexes, making the theoretical rationalization of experimental catalytic data difficult.
