107-86-8Relevant articles and documents
SBA-15-Functionalized 3-Oxo-ABNO as Recyclable Catalyst for Aerobic Oxidation of Alcohols under Metal-Free Conditions
Karimi, Babak,Farhangi, Elham,Vali, Hojatollah,Vahdati, Saleh
, p. 2735 - 2741 (2014)
The nitroxyl radical 3-oxo-9-azabicyclo [3.3.1]nonane-N-oxyl (3-oxo-ABNO) has been prepared using a simple protocol. This organocatalyst is found to be an efficient catalyst for the aerobic oxidation of a wide variety of alcohols under metal-free conditions. In addition, the preparation and characterization of a supported version of 3-oxo-ABNO on ordered mesoporous silica SBA-15 (SABNO) is described for the first time. The catalyst has been characterized using several techniques including simultaneous thermal analysis (STA), transmission electron microscopy (TEM), and nitrogen sorption analysis. This catalyst exhibits catalytic performance comparable to its homogeneous analogue and much superior catalytic activity in comparison with (2,2,6,6-tetramethylpiperidin-1-yl)oxy (TEMPO) for the aerobic oxidation of almost the same range of alcohols under identical reaction conditions. It is also found that SABNO can be conveniently recovered and reused at least 12 times without significant effect on its catalytic efficiency.
Copper-doped sulfonic acid-functionalized MIL-101(Cr) metal–organic framework for efficient aerobic oxidation reactions
Li, Xiujuan,Zhou, Zihao,Zhao, Yuzhen,Ramella, Daniele,Luan, Yi
, (2020)
A series of Cr-based metal–organic framework MIL-101-SO3H bearing sulfonic acid functional groups were utilized for the immobilization of catalytically active copper species via a post-synthetic metalation method. The novel materials were fully characterized by scanning electron microscopy, X-ray diffraction, energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), the Brunauer–Emmett–Teller method, and thermogravimetric analysis. XPS and the EDX element map both suggested that Cu2+ is coordinately bonded to the MIL-101-SO3H, which forms the MIL-101-SO3@Cu structure. The obtained copper-doped MIL-101-SO3@Cu-1, MIL-101-SO3@Cu-2, and MIL-101-SO3@Cu-3 catalysts were utilized in the selective oxidation of alcohols and epoxidation of olefins using molecular oxygen as an oxidant. Catalytic aerobic oxidation optimization showed that MIL-101-SO3@Cu-1 is the optimal catalyst and it can be reused ten times without compromising the yield and selectivity.
Aerobic oxidation of alcohols using various types of immobilized palladium catalyst: The synergistic role of functionalized ligands, morphology of support, and solvent in generating and stabilizing nanoparticles
Karimi, Babak,Zamani, Asghar,Abedi, Sedigheh,Clark, James H.
, p. 109 - 119 (2009)
Preparation and characterization of a variety of immobilized palladium catalyst, based on either ligand functionalized amorphous or ordered mesoporous silica, is described. The resulting Pd-loaded materials act as efficient catalyst for the oxidation of a variety of alcohols using molecular oxygen and air. Our studies show that in the case of supported palladium catalyst on hybrid amorphous silica, the nature of ligand and the solvent could effectively control the generation of nanoparticles. Furthermore, we have found that nanoparticles with smaller size and higher activity were generated from the anchored palladium precursor when the aerobic oxidation of alcohols was carried out in α,α,α-trifluorotoluene (TFT) instead of toluene. On the other hand, in the case of aerobic oxidation reactions by using supported palladium catalyst on hybrid SBA-15, the combination of organic ligand and ordered mesoporous channels resulted in an interesting synergistic effect that led to enhanced activity, prevention of Pd nanoparticles agglomeration, and finally generation of a durable catalyst.
Studies on the synthesis of elegan-type linear diterpenes: The efficient total syntheses of eleganolone, eleganolone acetate, elegandiol, eleganonal, and epoxyeleganolone
Li,Lan,Liu,Li
, p. 92 - 95 (1998)
The first total syntheses of five elegan-type linear diterpenes- eleganolone (1), eleganolone acetate (2), elegandiol (3), eleganonal (4), and epoxyeleganolone (5)-were accomplished starting from (E,E)-farnesol (6) via four to six steps, successively, with high overall yield. The key step was the alkylation reaction of silyl cyanide with allylic iodide.
A comparison of intrazeolite and solution singlet oxygen ene reactions of allylic alcohols
Clennan, Edward L.,Zhang, Dong,Singleton, Jamie
, p. 1226 - 1232 (2006)
The singlet oxygen ene reactions of four allylic alcohols and for comparison an allylic ether have been examined both in solution and in zeolite Y. Bronsted acid sites in the zeolite were shown to induce decomposition of several of the allylic alcohols. Treatment of the zeolites with pyridine removed these acid sites and allowed intrazeolite reactions of the allylic alcohols without interference from decomposition. Control reactions with an allylic alcohol that is inert to decomposition provided evidence that the presence of pyridine in the zeolite labyrinth does not influence the product composition.
A highly recyclable magnetic core-shell nanoparticle-supported TEMPO catalyst for efficient metal- and halogen-free aerobic oxidation of alcohols in water
Karimi, Babak,Farhangi, Elham
, p. 6056 - 6060 (2011)
The selective oxidation of primary and secondary alcohols to the corresponding carbonyl compounds is one of the most challenging reactions in organic chemistry. Many oxidizing reagents such as stoichiometric CrVI salts, DMSOcoupled reagents, and hypervalent iodine have been traditionally used to accomplish this transformation. However, these reagents show poor atom efficiency and are often toxic; their widespread use thereby causes significant environmental concerns that render them impractical. As a consequence, due to ever-increasing environmental standards and economic pressures, there is substantial interest towards the use of heterogeneous and recyclable catalysts to achieve the efficient oxidation of alcohols with molecular oxygen or air as the oxidant. Whereas methodologies for the improvement of catalytic activities and selectivities have been developed considerably, they may possibly leave toxic traces of heavy metals in the products. Moreover, many of the metal-based catalyst systems are often deactivated because of the occupation of coordination sites with the by-produced water and so they generally require the use of organic solvents. Therefore, it seems that there is still a great interest in developing efficient and non-metallic catalysts for the aerobic oxidation of alcohols from the viewpoint of socalled green and sustainable chemistry. Of particular interest in this area is the application of the stable nitroxyl radical 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) in combination with various types of non-metallic, stoichiometric co-oxidants as an alternative to metal-based oxidants.
Intensification of TEMPO-mediated aerobic alcohol oxidations under three-phase flow conditions
Aellig, Christof,Scholz, David,Conrad, Sabrina,Hermans, Ive
, p. 1975 - 1980 (2013)
Various homogeneous and heterogeneous catalytic systems based on 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) and different (co-)oxidants have been reported for the selective oxidation of alcohols. Herein we report the use of a commercially available silica-immobilized TEMPO catalyst, in combination with catalytic amounts of HNO3 as a NOx source under continuous three-phase flow conditions. First the stability of the catalyst was evaluated with benzyl alcohol and the reaction parameters were optimized. Subsequently different substrates were tested, focusing on the oxidation of renewable substrates like lactic acid and 5-hydroxymethylfurfural (HMF).
Shape-selective isomerisation of α-acetylenic alcohols to α,β-ethylenic carbonyl compounds by vanadium-pillared montmorillonite catalyst
Choudary,Durga Prasad,Valli
, p. 7521 - 7522 (1990)
A very simple, convenient method for an efficient shape-selective isomerisation of acyclic and aromatic α-acetylenic alcohols only, to the corresponding α,β-ethylenic carbonyl compounds, leaving the cyclic ones unreacted using catalytic amounts of vanadium-pillared montmorillonite catalyst, having -Si-O-V=0 groups with successful reusability is described.
Properties of Ti-beta zeolites synthesized by dry-gel conversion and hydrothermal methods
Tatsumi, Takashi,Jappar, Nizamidin
, p. 7126 - 7131 (1998)
The large-pore beta zeolite containing Ti has been synthesized in the presence of alkali cations (Na+) by a dry-gel conversion (DGC) technique using tetraethylammonium hydroxide (TEAOH) as a structure-directing agent. The obtained Ti-beta zeolites were compared with hydrothermally synthesized (HTS) Ti-beta. It was found that Ti-beta-DGC samples adsorbed less water (12-13 wt %) than Ti-beta-HTS (19 wt %), indicating that Ti-beta-DGC is more hydrophobic than Ti-beta-HTS. We propose that this leads to a higher activity for the former in the oxidation of cyclohexane. Upon being washed with H2SO4, the turnover number (TON) of DGC samples slightly increased for the oxidation of cyclohexane. DGC and HTS samples demonstrated no significant difference in the activity for oxidation reactions of unsaturated alcohols and C6-C8 cyclic alcohols.
Au/Cu-fiber catalyst with enhanced low-temperature activity and heat transfer for the gas-phase oxidation of alcohols
Zhao, Guofeng,Hu, Huanyun,Deng, Miaomiao,Ling, Min,Lu, Yong
, p. 55 - 58 (2011)
A microfibrous-structured gold catalyst was successfully prepared by gold galvanic deposition on a thin-sheet sinter-locked Cu-fibers. The catalyst has excellent heat transfer ability and enhanced low-temperature activity suitable for gas-phase oxidation of alcohols. The AuCu(alloy)-Cu2O active composites formed during reaction and their cooperative effect contribute to promoting the low-temperature activity.
