822-67-3Relevant articles and documents
Selective allylic oxidation of cyclohexene over a novel nanostructured CeO2–Sm2O3/SiO2 catalyst
Rao, Bolla Govinda,Sudarsanam, Putla,Nallappareddy,Yugandhar Reddy,Venkateshwar Rao,Reddy, Benjaram M.
, p. 6151 - 6168 (2018)
Abstract: Selective allylic oxidation of cyclohexene was investigated over nanostructured CeO2/SiO2 and CeO2–Sm2O3/SiO2 catalysts synthesized by a feasible deposition precipitation method. The CeO2–Sm2O3/SiO2 catalyst showed excellent catalytic efficiency with ~89?% cyclohexene conversion and ~90?% selectivity for allylic products (i.e., 2-cyclohexen-1-ol and 2-cyclohexene-1-one), while only ~50 and ~35?% cyclohexene conversion was observed, respectively, over CeO2/SiO2 and CeO2 catalysts. Systematic characterization of the designed catalysts was undertaken to correlate their catalytic activity with the physicochemical properties using X-ray diffraction (XRD) analysis, Brunauer–Emmett–Teller (BET) surface area measurements, Raman spectroscopy, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and NH3-temperature programmed desorption (TPD) techniques. The results revealed that doping of Sm3+ into the ceria lattice and simultaneous dispersion of resultant Ce–Sm mixed oxides on the silica surface led to improved structural, acidic, and catalytic properties. The better catalytic efficiency of CeO2–Sm2O3/SiO2 was due to high specific surface area, more structural defects, and high concentration of strong acid sites, stimulated by synergistic interaction between various oxides in the catalyst. The cyclohexene conversion and selectivity for allylic products depended on the reaction temperature, nature of solvent, molar ratio of cyclohexene to oxidant, and reaction time. Possible reaction pathways are proposed for selective allylic oxidation of cyclohexene towards 2-cyclohexen-1-ol and 2-cyclohexene-1-one products. Graphical Abstract: SiO2-supported CeO2–Sm2O3 nanocatalyst exhibited outstanding catalytic performance with superior selectivity for allylic products in liquid-phase selective oxidation of cyclohexene under mild reaction conditions.[Figure not available: see fulltext.].
Selective hydroxylation of cyclohexene in water as an environment-friendly solvent with hydrogen peroxide over febipyridine encapsulated in y-type zeolite
Yamaguchi, Syuhei,Fukura, Tomohiro,Fujita, Chiharu,Yahiro, Hidenori
, p. 713 - 715 (2012)
The selective hydroxylation of cyclohexene to 2-cyclohexen- 1-ol with hydrogen peroxide in water was successfully achieved using [Fe(bpy) 3]2+ complexes encapsulated into Y-type zeolite.
Highly efficient and expeditious PdO/SBA-15 catalysts for allylic oxidation of cyclohexene to cyclohexenone
Ganji, Saidulu,Bukya, Padma,Vakati, Venkateswarlu,Rao, Kamaraju Seetha Rama,Burri, David Raju
, p. 409 - 414 (2013)
A series of four PdO/SBA-15 catalysts with 1, 2, 4, 5% (by weight) loading of PdO have been prepared by a conventional impregnation method and are characterized by N2-adsorption, low-angle and wide-angle XRD, XPS and TEM techniques. The catalys
Four-coordinate trispyrazolylboratomanganese and -iron complexes with a pyrazolato Co-ligand: Syntheses and properties as oxidation catalysts
Tietz, Thomas,Limberg, Christian,Stoesser, Reinhard,Ziemer, Burkhard
, p. 10010 - 10020 (2011)
A series of complexes of the type [(TpR1,R2)M(X)] (Tp=trispyrazolylborato) with R1/R2 combinations Me/tBu, Ph/Me, iPr/iPr, Me/Me and for M=Mn or Fe coordinating [PzMe,tBu] - (Pz=pyrazolato) or Cl
Synthesis and characterization of Au nanocatalyst on modifed bentonite and silica and their applications for solvent free oxidation of cyclohexene with molecular oxygen
Shahabi Nejad,Ghasemi,Martínez-Huerta,Ghiaci
, p. 118 - 126 (2015)
In the present work, the selective liquid phase oxidation of cyclohexene mainly to 2-cyclohexe-1-one has been investigated over gold nanoparticles (GNPs) with molecular oxygen in a solvent-free condition. Gold nanoparticles were synthesised on two modifie
Solvent-free oxidation of cyclohexene over catalysts Au/OMS-2 and Au/La-OMS-2 with molecular oxygen
Cai, Zhen-Yu,Zhu, Ming-Qiao,Chen, Jun,Shen, Yang-Yi,Zhao, Jing,Tang, Yue,Chen, Xin-Zhi
, p. 197 - 201 (2010)
Supported gold catalysts Au/OMS-2 and Au/La-OMS-2 were prepared and used for liquid phase oxidation of cyclohexene with oxygen as an oxidant. These catalysts were characterized by XRD, SEM, TEM and EDX. The reactions were carried out in an autoclave at 80
An expedient synthesis of perfluorinated tetraazamacrocycles: New ligands for copper-catalyzed oxidation under fluorous biphasic conditions
De Castries, Augustin,Magnier, Emmanuel,Monmotton, Sophie,Fensterbank, Helene,Larpent, Chantal
, p. 4685 - 4692 (2006)
Conjugate additions of cyclam to perfluorohexyl vinyl sulfone and sulfoxide, which act as efficient fluorous Michael acceptors, readily give access to new fluoro-ponytail tetraazamacrocycles in good yields. The solubility of the N-tetrasubstituted macrocy
Highly Selective Hydrodeoxygenation of Lignin to Naphthenes over Three-Dimensional Flower-like Ni2P Derived from Hydrotalcite
Chen, Guanyi,Diao, Xinyong,Ji, Na,Jia, Zhichao,Li, Changzhi,Li, Xinxin,Liu, Caixia,Liu, Qingling,Lu, Xuebin,Ma, Longlong,Song, Chunfeng,Wang, Shurong,Zhao, Yujun
, p. 1338 - 1356 (2022/02/07)
A strategy for low-temperature synthesis of hydrotalcite-based nickel phosphide catalysts (Ni2P-Al2O3) with flower-like porous structures was proposed. The in situ reduction of red phosphorus at 500 °C enables Ni2P catalysts with small particle size and abundant active and acidic sites, which facilitate the activation of substrates and H2. In the hydrodeoxygenation of guaiacol, a 100% conversion and 94.5% yield of cyclohexane were obtained over the Ni2P-Al2O3 catalyst under 5 MPa H2 at 250 °C for 3 h. Other lignin-derived phenolic compounds could also afford the corresponding alkanes with yields higher than 85%. Moreover, Ni2P-Al2O3 exhibited high hydrodeoxygenation activity in the deconstruction of more complex wood structures, including lignin oil and real lignin. Among the two different types of Ni sites of Ni(1) and Ni(2) in Ni2P, density functional theory (DFT) calculations showed that the Ni(2) site, highly exposed on the Ni2P-Al2O3 surface, possesses a stronger ability to break C-OH bonds during the hydrodeoxygenation of guaiacol in comparison with the Ni(1) site.
Organocatalytic epoxidation and allylic oxidation of alkenes by molecular oxygen
Orfanidou, Maria,Petsi, Marina,Zografos, Alexandros L.
supporting information, p. 9172 - 9178 (2021/11/30)
Pyrrole-proline diketopiperazine (DKP) acts as an efficient mediator for the reduction of dioxygen by Hantzsch ester under mild conditions to allow the aerobic metal-free epoxidation of electron-rich alkenes. Mechanistic crossovers are underlined, explaining the dual role of Hantzsch ester as a reductant/promoter of the DKP catalyst and a simultaneous competitor for the epoxidation of alkenes when HFIP is used as a solvent. Expansion of this protocol to the synthesis of allylic alcohols was achieved by adding a catalytic amount of selenium dioxide as an additive, revealing a superior method to the classical application of t-BuOOH as a selenium dioxide oxidant.
Catalytic epoxidation of β-ionone with molecular oxygen using selenium-doped silica materials
Cao, Kuanhong,Jing, Xiaobi,Li, Peizi,Liu, Yonghong,Yu, Lei
, p. 17241 - 17246 (2021/10/04)
A novel Se-doped silica material was fabricated, and this easily prepared material could be used as an efficient recyclable catalyst for β-ionone oxidation. Interestingly, by doping with fluorine in the catalyst, the reaction selectivity was significantly enhanced to produce the important pharmaceutical intermediate β-ionone epoxide selectively. Characterization of the materials indicated that by doping with F, the electropositivity of the catalytic Se species was obviously enhanced due to the strong electron-withdrawing features of F, and this was a key factor for controlling the reaction selectivity in the β-ionone epoxidation reaction. The electropositivity of a silica support might also increase and the reinforced electropositivity of Si sites might be beneficial for the adsorption of a β-ionone substrate and for the contact of the electron-enriched endocyclic C-C with the catalyst.
