66-25-1Relevant articles and documents
Manganese dioxide supported on aluminum silicate: A new reagent for oxidation of alcohols under heterogeneous conditions
Huang, Li-Hong,Ma, Yi-Chun,Zhang, Changhe,Wang, Qiang,Zou, Xiao-Nan,Lou, Ji-Dong
, p. 3377 - 3382 (2012)
Manganese dioxide supported on aluminum silicate, under heterogeneous conditions at reflux, selectively oxidized aromatic primary and secondary alcohols into the corresponding aldehydes and ketones, respectively, in yields of 87-96%. The present method failed to oxidize aliphatic alcohols.
Chromium(VI) Oxidation of Alkanol Components of Sodium Dodecyl Sulfate Reverse Micelles
Rodenas, E.,Perez-Benito, E.
, p. 9496 - 9500 (1991)
Oxidation with potassium dichromate in perchloric acid medium of the alkanols 1-butanol, 1-hexanol, and 1-octanol, components of sodium dodecyl sulfate reverse micelles in alkanols, has been studied.The reaction rate is first-order with respect to Cr(VI) and depends linearly on the HClO4 concentration in the aqueous phase, but the reaction rate decreases with the amount of alcohol in the reverse micelles.To explain the kinetic results it is necessary to consider the intermicellar exchange of the reactants, which could depend on the thickness of the layer where the surfactant and the alcohol are located.
Supported Au-Cu bimetallic alloy nanoparticles: An aerobic oxidation catalyst with regenerable activity by visible-light irradiation
Sugano, Yoshitsune,Shiraishi, Yasuhiro,Tsukamoto, Daijiro,Ichikawa, Satoshi,Tanaka, Shunsuke,Hirai, Takayuki
, p. 5295 - 5299 (2013)
Rejuvenating sunlight: Supported Au-Cu bimetallic alloy nanoparticles promote aerobic oxidation at room temperature under visible light (λ>450 nm) irradiation with little deactivation by the oxidation of surface Cu atoms by oxygen. This is achieved through the reduction of oxidized surface Cu atoms by the surface Au atoms, a process which is activated by visible-light irradiation, even by sunlight. Copyright
FATTY ACID HYDROPEROXIDE LYASE IN TOBACCO CELLS CULTURED IN VITRO
Sekiya, Jiro,Tanigawa, Satoru,Kajiwara, Tadahiko,Hatanaka, Akikazu
, p. 2439 - 2444 (1984)
Fatty acid hydroperoxide lyase (HPO lyase) was found in green and non-green tobacco cells cultured in vitro.The HPO lyase activity in non-green cells was 1/3-1/2 of that in green cells.When the cells were transferred from the light to dark conditions or vice versa, cells turned non-green or green according to the light conditions.The HPO lyase activity also changed according to the light conditions, but the changes in HPO lyase activities were not proportional to the changes in chlorophyll contents.These results suggest that at least two types of HPO lyases are present in the green cells.One type of HPO lyase is perhaps common both to the green and non-green cells; another one is chloroplastic.The fatty acid compositions of cells and substrate specificities of HPO lyase differed between green and non-green cells.Key Word Index - Nicotiana tabacum; Solanaceae; cultured tobacco cells; green cells; fatty acid hydroperoxide lyase; linoleic acid; linolenic acid; C6-aldehydes.
Functionalized-1,3,4-oxadiazole ligands for the ruthenium-catalyzed Lemieux-Johnson type oxidation of olefins and alkynes in water
Hkiri, Shaima,Touil, Soufiane,Samarat, Ali,Sémeril, David
, (2021/11/30)
Three arene-ruthenium(II) complexes bearing alkyloxy(5-phenyl-1,3,4-oxadiazol-2-ylamino)(4-trifluoromethylphenyl)methyl ligands were quantitatively obtained through the reaction of (E)-1-(4-trifluoromethylphenyl)-N-(5-phenyl-1,3,4-oxadiazol-2-yl)-methanimine with the ruthenium precursor [RuCl2(η6-p-cymene)]2 in a mixture of the corresponding alcohol and CH2Cl2 at 50 °C. The obtained complexes were fully characterized by elemental analysis, infrared, NMR and mass spectrometry. Solid-state structures confirmed the coordination of the 1,3,4-oxadiazole moiety to the ruthenium center via their electronically enriched nitrogen atom at position 3 in the aromatic ring. These complexes were evaluated as precatalysts in the Lemieux-Johnson type oxidative cleavage of olefins and alkynes in water at room temperature with NaIO4 as oxidizing agent. Good to full conversions of olefins into the corresponding aldehydes were measured, but low catalytic activity was observed in the case of alkynes. In order to get more insight into the mechanism, three analogue arene-ruthenium complexes were synthesized and tested in the oxidative cleavage of styrene. The latter tests clearly demonstrated the importance of the hemilabile alkyloxy groups, which may form more stable (N,O)-chelate intermediates and increase the efficiency of the cis-dioxo-ruthenium(VI) catalyst.
One-Pot Bioelectrocatalytic Conversion of Chemically Inert Hydrocarbons to Imines
Chen, Hui,Tang, Tianhua,Malapit, Christian A.,Lee, Yoo Seok,Prater, Matthew B.,Weliwatte, N. Samali,Minteer, Shelley D.
supporting information, p. 4047 - 4056 (2022/02/10)
Petroleum hydrocarbons are our major energy source and an important feedstock for the chemical industry. With the exception of combustion, the deep conversion of chemically inert hydrocarbons to more valuable chemicals is of considerable interest. However, two challenges hinder this conversion. One is the regioselective activation of inert carbon-hydrogen (C-H) bonds. The other is designing a pathway to realize this complicated conversion. In response to the two challenges, a multistep bioelectrocatalytic system was developed to realize the one-pot deep conversion from heptane to N-heptylhepan-1-imine under mild conditions. First, in this enzymatic cascade, a bioelectrocatalytic C-H bond oxyfunctionalization step based on alkane hydroxylase (alkB) was applied to regioselectively convert heptane to 1-heptanol. By integrating subsequent alcohol oxidation and bioelectrocatalytic reductive amination steps based on an engineered choline oxidase (AcCO6) and a reductive aminase (NfRedAm), the generated 1-heptanol was successfully converted to N-heptylhepan-1-imine. The electrochemical architecture provided sufficient electrons to drive the bioelectrocatalytic C-H bond oxyfunctionalization and reductive amination steps with neutral red (NR) as electron mediator. The highest concentration of N-heptylhepan-1-imine achieved was 0.67 mM with a Faradaic efficiency of 45% for C-H bond oxyfunctionalization and 70% for reductive amination. Hexane, octane, and ethylbenzene were also successfully converted to the corresponding imines. Via regioselective C-H bond oxyfunctionalization, intermediate oxidation, and reductive amination, the bioelectrocatalytic hydrocarbon deep conversion system successfully realized the challenging conversion from inert hydrocarbons to imines that would have been impossible by using organic synthesis methods and provided a new methodology for the comprehensive conversion and utilization of inert hydrocarbons.
Green, homogeneous oxidation of alcohols by dimeric copper(II) complexes
Maurya, Abhishek,Haldar, Chanchal
, p. 885 - 904 (2020/12/18)
Three pyrazole derivatives, 3,5-dimethyl-1H-pyrazole (DMPz) (I), 3-methyl-5-phenyl-1H-pyrazole (MPPz) (II), and 3,5-diphenyl-1H-pyrazole (DPPz) (III), were prepared via reacting semicarbazide hydrochloride with the acetylacetone, 1-phenylbutane-1,3-dione, and 1,3-diphenylpropane-1,3-dione, respectively. Complexes 1–3 were isolated by reacting CuCl2·2H2O with I–III, respectively, and characterized by CHNS elemental analyses, FT-IR, UV-Vis, 1H and 13C NMR, EPR spectra, and TGA/DTA. Molecular structures of the pyrazole derivatives I–III and copper(II) complexes 2 and 3 were studied through single-crystal XRD analysis to confirm their molecular structures. Overlapping of hyperfine splitting in the EPR spectra of the dimeric copper(II) complexes 1–3 indicates that both copper centers do not possess the same electronic environment in solution. The copper(II) complexes are dimeric in solid state as well as in solution and catalyze the oxidation of various primary and secondary alcohols selectively. Catalysts 1–3 show more than 92% product selectivity toward ketones during the oxidation of secondary alcohols. Surprisingly primary alcohols, which are relatively difficult to oxidize, produce carboxylic acid as a major product (48%–90% selectivity) irrespective of catalytic systems. The selectivity for carboxylic acid rises with decreasing the carbon chain length of the alcohols. An eco-friendly and affordable catalytic system for oxidation of alcohols is developed by the utilization of H2O2, a green oxidant, and water, a clean and greener solvent, which is a notable aspect of the study.
Synthesis of TEMPO radical decorated hollow porous aromatic frameworks for selective oxidation of alcohols
Shen, Yan-Ming,Xue, Yun,Yan, Mi,Mao, Hui-Ling,Cheng, Hu,Chen, Zhuo,Sui, Zhi-Wei,Zhu, Shao-Bin,Yu, Xiu-Jun,Zhuang, Jin-Liang
supporting information, p. 907 - 910 (2021/02/06)
A bottom-up approach was developed to prepare TEMPO radical decorated hollow aromatic frameworks (HPAF-TEMPO) by using TEMPO radical functionalized monomers and SiO2nanospheres as templates. The accessible inner layer, high density of TEMPO sites, and hybrid micro-/mesopores of the HPAF-TEMPO enable the aerobic oxidation of a broad range of alcohols with high efficiency and excellent selectivity.
Solvent-free oxidation of straight-chain aliphatic primary alcohols by polymer-grafted vanadium complexes
Chaudhary, Nikita,Haldar, Chanchal,Kachhap, Payal
, (2021/12/02)
Oxidovanadium(IV) complexes [VO(tertacac)2] (1), [VO(dipd)2] (2), and [VO(phbd)2] (3) were synthesized by reacting [VO(acac)2] with 2,2,6,6-tetramethyl-3,5-hepatanedione, 1,3-diphenyl-1,3-propanedione, and 1-phenyl-1,3-butanedione, respectively. Imidazole-modified Merrifield resin was used for the heterogenization of complexes 1–3. During the process of heterogenization, the V4+ center in complex 2 converts into V5+, whereas the other two complexes 1 and 3 remain in the oxidovanadium(IV) state in the polymer matrix. Theoretically, calculated IPA values of 1–3 suggest that 2 is prone to oxidation compared with 1 and 3, which was also supported by the absence of EPR lines in 5. Polymer-supported complexes Ps-Im-[VIVO(tertacac)2] (4), Ps-Im-[VVO2(dipd)2] (5), and Ps-Im-[VIVO(phbd)2] (6) were applied for the solvent-free heterogenous oxidation of a series of straight-chain aliphatic alcohols in the presence of H2O2 at 60°C and showed excellent substrate conversion specially for the alcohols with fewer carbon atoms. Higher reaction temperature improves the substrate conversion significantly for the alcohols containing more carbon atoms such as 1-pentanol, 1-hexanol, and 1-heptanol while using optimized reaction conditions. However, alcohols with fewer carbon atoms seem less affected by reaction temperatures higher than the optimized temperature. A decreasing trend in the selectivity(%) of carboxylic acid was observed with increasing carbon atoms among the examined alcohols, whereas the selectivity towards aldehydes increased. The order of efficiency of the supported catalysts is 4 > 6 > 5 in terms of turnover frequency (TOF) values and substrate conversion, further supported by theoretical calculations.
Catalyst composition containing bidentate phosphine ligand and application thereof
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Paragraph 0068; 0081-0084, (2021/11/03)
The catalyst composition comprises a bidentate phosphine ligand and a rhodium complex, wherein the skeleton of the bidentate phosphine ligand not only has C. 2 The symmetry and the appropriate rigidity, and the phosphine ligand derived based on the skeleton can provide effective steric hindrance around the catalyst center metal, so that the selectivity of the catalyst can be remarkably improved, the aldehyde yield is not lower 92% when the catalyst combination is applied to the hydroformylation reaction, and the selectivity of n-aldehyde is not lower 90%. In addition, the raw materials olefins with different structures can obtain outstanding reaction rate and normal aldehyde selectivity as compared with the existing catalyst systems, and can be suitable for the hydroformylation reaction of more types of olefins.
