36995-20-7Relevant academic research and scientific papers
A preparing method of p-nitroacetophenone
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Paragraph 0063-0065, (2019/01/07)
A preparing method of p-nitroacetophenone is disclosed. The method includes reacting p-nitroethylbenzene, as a raw material, in an autoclave at 110-150 DGE C for 3-7 h under the function of a metalloporphyrin catalyst shown as a formula 1 or a formula 2 in an oxygen atmosphere having a pressure of 0.8-2 MPa under a condition of no solvent; and subjecting an obtained reaction liquid mixture to after-treatment to obtain the target product that is p-nitroacetophenone. The method includes reaction in the sealed autoclave, thus greatly reducing volatilization loss of the raw material, and avoidingemission of reaction waste gas so as to avoid environment pollution therefrom. The bionic metalloporphyrin catalyst which is naturally degradable is adopted as an auxiliary catalyst, is low in dosage,and can increase product selectivity. Consumption of an organic solvent and purification of the target product are avoided, thus reducing the cost.
Iron-based metalloporphyrins as efficient catalysts for aerobic oxidation of biomass derived furfural into maleic acid
Xie, Yongdi,Huang, Yi,Wu, Chunyan,Yuan, Wenwen,Xia, Yongmei,Liu, Xiang,Wang, Haijun
, p. 20 - 27 (2018/04/05)
A series of porphyrin type catalysts with the metal active sites of Fe were prepared and investigated in aerobic oxidation of biomass-based furfural to maleic acid (MAD) in aqueous phase. The catalytic performance of meso-tetrakis(4-bromophenyl)porphyrin iron (III) chloride (FeT(p-Br)PPCl) immobilized on different supports was evaluated. It was interesting to find that the catalytic activity varied with the supports and followed the trend: FeT(p-Br)PPCl/SBA–15 > FeT(p-Br)PPCl/meso-ZSM–5 > FeT(p-Br)PPCl/MCM-41. The effect of reaction conditions were discussed in detail over FeT(p-Br)PPCl/SBA-15 catalyst, and 56.1% yield and 73.8% selectivity of MAD were obtained from renewable furfural under the optimal conditions. Moreover, the FeT(p-Br)PPCl/SBA-15 catalyst could be reused five times without a significant decrease of activity in recycling examinations.
Cyclopropanation reactions catalysed by dendrimers possessing one metalloporphyrin active site at the core: Linear and sigmoidal kinetic behaviour for different dendrimer generations
Vin?, Petr,De Cózar, Abel,Rivilla, Iván,Nováková, Kate?ina,Zangi, Ronen,Cva?ka, Josef,Arrastia, Iosune,Arrieta, Ana,Dra?ar, Pavel,Miranda, José I.,Cossío, Fernando P.
, p. 1120 - 1131 (2016/07/06)
Experimental and computational studies on dendrimers possessing a Fe(porphyrin) catalytic core and polyether dendritic arms show that these macromolecules promote efficiently the (2+1) cycloaddition between a model alkene and diazomethane. The reaction is
Metalloporphyrin-Based Hypercrosslinked Polymers Catalyze Hetero-Diels–Alder Reactions of Unactivated Aldehydes with Simple Dienes: A Fascinating Strategy for the Construction of Heterogeneous Catalysts
Dou, Zhiyu,Xu, Li,Zhi, Yongfeng,Zhang, Yuwei,Xia, Hong,Mu, Ying,Liu, Xiaoming
supporting information, p. 9919 - 9922 (2016/07/19)
We describe a novel and intriguing strategy for the construction of efficient heterogeneous catalysts by hypercrosslinking catalyst molecules in a one-pot Friedel–Crafts alkylation reaction. The new hypercrosslinked polymers (HCPs) as porous solid catalysts exhibit the combined advantages of homogeneous and heterogeneous catalysis, owing to their high surface area, good stability, and tailoring of catalytic centers on the frameworks. Indeed, a new class of metalloporphyrin-based HCPs were successfully synthesized using modified iron(III) porphyrin complexes as building blocks, and the resulting networks were found to be excellent recyclable heterogeneous catalysts for the hetero-Diels–Alder reaction of unactivated aldehydes with 1,3-dienes. Moreover, this new strategy showed wide adaptability, and many kinds of homogeneous-like solid-based catalysts with high catalytic performance and excellent recyclability were also constructed.
Influence of substituents in meso-aryl groups of iron μ-oxo porphyrins on their catalytic activity in the oxidation of cycloalkanes
Tabor, Edyta,Po?towicz, Jan,Pamin, Katarzyna,Bas?g, Sylwia,Kubiak, W?adys?aw
, p. 342 - 349 (2016/10/09)
The aim of this work was to study the effect of substituents on the catalytic activity of iron μ-oxo porphyrins in oxidation of cycloalkanes. Electron-donating or electron-withdrawing substituents were introduced in meso-aryl groups of iron μ-oxo porphyrins. An important part of the work was the characterization of the catalysts, in particular their redox properties. Catalytic performance and selectivity were evaluated using cyclopentane, cyclohexane, and cyclooctane as model compounds. It was shown that not only electron-withdrawing but also electron-donating substituents improved the catalytic performance of iron μ-oxo complexes. Moreover, catalytic activity of iron μ-oxo porphyrins with electron-withdrawing substituents correlated with the half-wave potential E1/2while the catalytic activity of iron μ-oxo porphyrins with electron-donating substituents increased with the decrease of reduction potential ERED.
Synthesis, characterization and spectral properties of substituted tetraphenylporphyrin iron chloride complexes
Sun, Zhi-Cheng,She, Yuan-Bin,Zhou, Yang,Song, Xu-Feng,Li, Kai
experimental part, p. 2960 - 2970 (2011/06/21)
A series of substituted tetraphenylporphyrin iron chloride complexes [RTPPFe(III)Cl, R=o/p-NO2, o/p-Cl, H, o/p-CH3, o/p-OCH3] were synthesized by a novel universal mixed-solvent method and the spectral properties of free b
A green process for oxidation of p-nitrotoluene catalyzed by metalloporphyrins under mild conditions
Wang, Lanzhi,She, Yuanbin,Zhong, Rugang,Ji, Hongbing,Zhang, Yanhui,Song, Xufeng
, p. 757 - 761 (2012/12/22)
A novel synthetic technology of p-nitrobenzoic acid has been investigated with dioxygen by using metalloporphyrins RTPP-MIIICl (M = Fe, Co, Mn) as biomimetic catalysts. Oxidation of p-nitrotoluene to p-nitrobenzoic acid under 2.0 MPa of O2 in the presence of a microamount of metalloporphyrins (RTPP-MIIICl) at 55 °C was achieved with the highest (up to 90.4%) yield. Further research results show that the catalytic activities were relative to the nature of the substituted groups and the central metal ions of metalloporphyrins. For the metalloporphyrins with the same center metal ions, the greater the electron-withdrawing degree of groups in the porphyrin ring, the higher the catalytic activities of the metalloporphyrins. The catalytic activities for metalloporphyrins with different center metal ions followed the order RTPPMn IIICl > RTPP Fe IIICl > RTPP Co IIICl.
Identification of High-Valent Fluoroiron Porphyrin Intermediates Associated with the Electrocatalytic Functionalization of Hydrocarbons
Hickman, David L.,Nanthakumar, Alaganandan,Goff, Harold M.
, p. 6384 - 6390 (2007/10/02)
The difluoroiron(III) tetraphenylporphyrin complex undergoes a one-electron oxidation at 0.68 V (SCE) in contrast with values of 1.1 V measured for the monofluoroiron(III) porphyrin and the other five-coordinate iron(III) porphyrin complexes.Cyclic voltammetric oxidation of the difluoroiron(III) species in dichloromethane solution is quasi-reversible as a consequence of an EC mechanism.Reversible waves are favored at high scan rates and lower temperatures.Increased water content serves to make the oxidative cyclic voltammetric process irreversible presumably due to a disproportionation process.In the presence of added olefin substrates, this EC process permits efficient electrocatalytic oxidation to the epoxide, allylic alcohol, and enone.Tertiary carbon units are converted to the corresponding alcohol.Utilization of fluoride ion permits generation and low-temperature spectroscopic identification of a highly oxidized iron porphyrin species.The high-valent complex is produced at -78 deg C through addition of m-chloroperbenzoic acid to monofluoroiron(III) tetraarylporphyrins or by fluoride ion promoted disproportionation of the dication radical μ-oxo dimeric iron(III) porphyrin derivative.The oxidized iron porphyrin species is competent to effect olefin epoxidation at -78 deg C.Low-temperature 1H and 2H NMR spectroscopies demonstrate the porphyrin ?-cation radical nature of the high-valent species, in that porphyrin phenyl resonances are drastically shifted in alternating upfield and downfield directions.The electron spin resonance spectrum is consistent with an S = 3/2 ground state, and the high-valent intermediate is assigned a tentative fluorooxoiron(IV) porphyrin ?-cation radical formulation.
Oxochromium compounds. 1. Synthesis and properties of μ-oxo chromium-iron porphyrin and phthalocyanine compounds
Liston, David J.,Kennedy, Brendan J.,Murray, Keith S.,West, Bruce O.
, p. 1561 - 1567 (2008/10/08)
The reaction between CrIVO(P) and FeII(P′) leads to the formation of μ-oxo heterobinuclear complexes (P)CrOFe(P′) where P and P′ represent dianions of porphyrins that may be the same or different. [Abbreviations for the dianions of 5,10,15,20-tetraarylporphyrins: TPP, tetraphenylporphyrin; TTP, tetra-p-tolylporphyrin; TMP, tetrakis(p-methoxyphenyl)porphyrin; TFP, tetrakis(p-fluorophenyl)porphyrin; TCP, tetrakis(p-chlorophenyl)porphyrin; TXP, tetra-3,5-xylylporphyrin; OEP, the dianion of 2,3,7,8,12,13,17,18-octaethylporphyrin; Pc, the dianion of the phthalocyanine molecule.] The complexes react with heterocyclic Lewis bases, and these coordinate to Cr only. The visible, infrared, 1H NMR, and Mo?ssbauer spectra are reported for the compounds. The variation of magnetic susceptibility with temperature down to 4.2 K is interpreted in terms of strong antiferromagnetic coupling between Cr(III) (S = 3/2) and Fe(III) (S = 5/2) centers with J values in the range -130 to -150 cm-1. Zero field splitting effects are important at low temperatures. The reaction of CrO(TPP) with FeII(Pc) forms an analogous μ-oxo complex having porphyrin and phthalocyanine groups attached to Cr(III) and Fe(III), respectively.
