- Synthesis of bimagnetic ionic liquid and application for selective aerobic oxidation of aromatic alcohols under mild conditions
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The first bimagnetic ionic liquid based on Fe and TEMPO with cooperative functionalities not only exhibited strong paramagnetic behaviour at room temperature under an applied magnetic field of 5000 Oe but also proved to be an effective catalyst for select
- Miao, Cheng-Xia,Wang, Jin-Quan,Yu, Bing,Cheng, Wei-Guo,Sun, Jian,Chanfreau, Sebastien,He, Liang-Nian,Zhang, Suo-Jiang
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- Nitrolysis of 2,6,8,12-tetraacetyl-4,10-dibenzyl-2,4,6,8,10,12-hexaazatetracyclo[5.5.0.03,11.05,9]dodecane
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Nitrolysis of 2,6,8,12-tetraacetyl-4,10-dibenzyl-2,4,6,8,10,12-hexaazatetracyclo-[5.5.0.03,11.05,9]dodecane results in the substitution of benzyl groups by the nitro groups with the formation of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazatetracyclo[5.5.0.03,11.05,9]-dodecane. The reaction sequentially proceeds through the nitration of the benzyl groups predominantly at para-position, the substitution of one nitrobenzyl group with the nitro group, and the introduction of the second nitro group into the nitrobenzyl fragment. The replacement of the remaining dinitrobenzyl fragment is a more difficult process, which reaches completion only by the end of the nitration. Another reaction product is p-nitrobenzoic acid, which is formed in the secondary reactions. No substitution of a p-nitrobenzoyl group with the nitro group takes place in the nitration of 2,6,8,12-tetraacetyl-4,10-di(p-nitrobenzoyl)-2,4,6,8,10,12-hexaazatetracyclo[5.5.0.03,11.05,9]dodecane under similar conditions.
- Kalashnikov,Sysolyatin,Sakovich,Dubkov,Kulagina
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- Continuous flow nitration of benzaldehyde
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The nitration of benzaldehyde can be carried out in a safe manner in continuous mode using a microreactor system. Choice of a micromixer was seen to affect the performance of this two-phase reaction significantly. The reaction time could be brought down to 2 min by increasing the reaction temperature and thereby taking advantage of higher heat transfer area. The simple T-micromixer is seen to be inefficient for two-phase reactions. Further scope of process intensification is also discussed.
- Kulkarni, Amol A.,Kalyani, Vishwanath S.,Joshi, Ramesh A.,Joshi, Rohini R.
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- Conversion of oximes into carbonyl compounds with thalium(III) nitrate supported onto HZSM-5 zeolite under microwave irradiation in solventless system
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Oximes are oxidatively deprotected by thalium(III) nitrate supported onto HZSM-5 zeolite to the parent carbonyl compounds in high yields upon exposure to microwave irradiation.
- Heravi, Majid M.,Ghassemzadeh, Mitra
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- Kinetics and Thermodynamics of Restricted Rotation of the Formyl Group in Nitrobenzaldehyde Anion Radicals
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The barrier to rotation about the carbonyl carbon-phenyl carbon bond of 3-nitrobenzaldehyde anion radical in N,N-dimethylformamide solution has been determined by a detailed line-shape analysis of the corresponding electron paramagnetic resonance (EPR) spectra at different temperatures.At 25 deg C the cis conformation is favored by 0.98 kcal mol-1 in free energy, and the free-energy barrier to the cis-trans conversion amounts to 9.35 kcal mol-1.Both enthalpy and entropy contributions to the free-energy profile are accurately evaluated (ΔH = 3.91, ΔH0 = -1.13 kcal mol-1; ΔS = -18.2, ΔS0 = -7.1 cal mol-1 K-1).The effects of ionic association and solvation on the barrier are discussed.The EPR spectra of 4-nitrobenzaldehyde and 2-nitrobenzaldehyde anion radicals are also reported as a function of temperature.In these cases, the barriers to internal rotation are too high to be surmounted on the EPR time scale.STO-3G ab initio MO calculations are given for benzaldehyde, 3-nitrobenzaldehyde, 4-nitrobenzaldehyde, and the corresponding anion radicals.The spin distribution in the anion radicals is calculated by McLachlan and INDO methods.
- Branca, Mario,Gamba, Aldo,Barzaghi, Mario,Simonetta, Massimo
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- Oxidation of benzyl alcohols under mild heterogeneous conditions
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A combination of iodic acid with ammonium dichromate in the presence of wet SiO2 was used as an efficient oxidizing agent for the transformation of benzyl alcohols to the corresponding aldehydes and ketones in n-hexane or without a solvent at r
- Shirini,Zolfigol,Azadbar
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- Facile open air oxidation of benzylic alcohols in distilled water by in situ made copper(II) complexes
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A highly efficient, selective and green catalytic protocol for open air oxidation of primary benzylic alcohols into aldehydes by in situ made N-isopropyl-3,5-di-tert-butylsalicylaldimine (HL3)-Cu(II) complexes and TEMPO (2,2,6,6-tetramethyl-piperidinyloxy
- Ahmad, Jahir Uddin,R?is?nen, Minna T.,Kemell, Marianna,Heikkil?, Mikko J.,Leskel?, Markku,Repo, Timo
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- Photoinduced Iron-Catalyzed ipso-Nitration of Aryl Halides via Single-Electron Transfer
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A photoinduced iron-catalyzed ipso-nitration of aryl halides with KNO2 has been developed, in which aryl iodides, bromides, and some of aryl chlorides are feasible. The mechanism investigations show that the in situ formed iron complex by FeSO4, KNO2, and 1,10-phenanthroline acts as the light-harvesting photocatalyst with a longer lifetime of the excited state, and the reaction undergoes a photoinduced single-electron transfer (SET) process. This work represents an example for the photoinduced iron-catalyzed Ullmann-type couplings.
- Wu, Cunluo,Bian, Qilong,Ding, Tao,Tang, Mingming,Zhang, Wenkai,Xu, Yuanqing,Liu, Baoying,Xu, Hao,Li, Hai-Bei,Fu, Hua
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p. 9561 - 9568
(2021/08/06)
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- Non-alkylator anti-glioblastoma agents induced cell cycle G2/M arrest and apoptosis: Design, in silico physicochemical and SAR studies of 2-aminoquinoline-3-carboxamides
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Malignant gliomas are the most common brain tumors, with generally dismal prognosis, early clinical deterioration and high mortality. Recently, 2-aminoquinoline scaffold derivatives have shown pronounced activity in central nervous system disorders. We herein reported a series of 2-aminoquinoline-3-carboxamides as novel non-alkylator anti-glioblastoma agents. The synthesized compounds showed comparable activity to cisplatin against glioblastoma cell line U87 MG in vitro. Among them, we found that 6a displayed good inhibitory activity against A172 and U118 MG glioblastoma cell lines and induced cell cycle arrest in the G2/M phase and apoptosis in U87 MG by flow cytometry analysis. Additionally, 6a displayed low cytotoxicity to several normal human cell lines. In silico study showed 6a had promising physicochemical properties and was predicted to cross the blood–brain barrier. Moreover, preliminary structure–activity relationships are also investigated, shedding light on further modifications towards more potent agents on this series of compounds. Our results suggest this compound has a promising potential as an anti-glioblastoma agent with a differential effect between tumor and non-malignant cells.
- Gu, Xiangyu,Liu, Jianwen,Ni, Xintong,Qi, Yingxue,Qian, Xuhong,Shao, Xusheng,Xu, Xiaoyong,Yuan, Pengtao
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supporting information
(2021/09/22)
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- Nitration of deactivated aromatic compounds via mechanochemical reaction
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A variety of deactivated arenes were nitrated to their corresponding nitro derivatives in excellent yields under high-speed ball milling condition using Fe(NO3)3·9H2O/P2O5 as nitrating reagent. A radical involved mechanism was proposed for this facial, eco-friendly, safe, and effective nitration reaction.
- Wu, Jian-Wei,Zhang, Pu,Guo, Zhi-Xin
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supporting information
(2021/05/05)
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- Magneto-structural properties and reliability of (Mn/Ni/Zn) substituted cobalt-copper ferrite heterogeneous catalyst for selective and efficient oxidation of aryl alcohols
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Herein, M2+ substituted CoCuFe2O4 (M2+ = Mn, Zn, Ni) ferrites have been synthesized using the sol-gel auto combustion method. The structural, morphological and magnetic studies confirm the phase formation of pure magnetic cubic spinel MCoCuFe2O4 (M2+ = Mn, Zn, Ni) ferrites. The substitution with Mn, Ni and Zn does not show large variation in binding energies obtained from XPS of Cu (2p) that specifies identical copper concentration (Cu0.5) and substitution of only cobalt (Co2+) in Mn-F, Ni-F and Zn-F catalysts. Interestingly, MCoCuFe2O4 magnetic catalysts were explored for selective oxidation of a series of substituted benzyl alcohols. Catalyst Mn-F showed 93% conversion of benzyl alcohol while, Ni-F showed 95% conversion of 4-nitrobenzyl alcohol. Whereas, the catalyst Zn-F was showed 96% conversion for 4-methoxybenzyl alcohol. Additionally the results also indicate an efficient separation and recovery of the magnetic catalysts after four successive reuses without any considerable loss in its catalytic activity.
- Dhabbe, Rohant,Gaikwad, Pratapsingh,Kakade, Bhalchandra,Kamble, Prakash,Kurane, Rajnikant,Parase, Haridas,Sabale, Sandip
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- Cu-Mn Bimetallic Complex Immobilized on Magnetic NPs as an Efficient Catalyst for Domino One-Pot Preparation of Benzimidazole and Biginelli Reactions from Alcohols
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An efficient magnetically recyclable bimetallic catalyst by anchoring copper and manganese complexes on the Fe3O4 NPs was prepared and named as Fe3O4@Cu-Mn. It was founded as a powerful catalyst for the domino one-pot oxidative benzimidazole and Biginelli reactions from benzyl alcohols as a green protocol in the presence of air, under solvent-free and mild conditions. Fe3O4@Cu-Mn NPs were well characterized by FT-IR, XRD, FE-SEM, TEM, VSM, TGA, EDX, DLS, and ICP analyses. The optimum range of parameters such as time, temperature, amount of catalyst, and solvent were investigated for the domino one-pot benzimidazole and Biginelli reactions to find the optimum reaction conditions. The catalyst was compatible with a variety of benzyl alcohols, which provides favorable products with good to high yields for all of derivatives. Hot filtration and Hg poisoning tests from the nanocatalyst revealed the stability, low metal leaching and heterogeneous nature of the catalyst. To prove the synergistic and cooperative effect of the catalytic system, the various homologues of the catalyst were prepared and then applied to a model reaction separately. Finally, the catalyst could be filtered from the reaction mixture simply, and reused for five consecutive cycles with a minimum loss in catalytic activity and performance. Graphic Abstract: A new magnetically recyclable Cu/Mn bimetallic catalyst has been developed for domino one-pot oxidation-condensation of benzimidazole and Biginelli reactions from alcohols. [Figure not available: see fulltext.]
- Nasseri, Mohammad Ali,Rezazadeh, Zinat,Kazemnejadi, Milad,Allahresani, Ali
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p. 1049 - 1067
(2020/09/11)
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- Preparation method of O-nitrobenzaldehyde
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The invention discloses a preparation method of o-nitrobenzaldehyde, wherein the preparation method comprises the following steps: (1) adding o-nitrobenzyl alcohol, a catalyst, a bromide salt and a solvent into a reaction kettle, and uniformly stirring at
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Paragraph 0026; 0028-0039
(2021/07/11)
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- Fe(III) superoxide radicals in halloysite nanotubes for visible-light-assisted benzyl alcohol oxidation and oxidative C[sbnd]C coupling of 2-naphthol
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Selective oxidation of benzyl alcohols to aldehydes and 2-naphthol to BINOL was achieved by activation of molecular oxygen (O2) and hydrogen peroxide (H2O2) over an iron-oxide catalyst embedded in halloysite nanotube. Electron spin resonance spectroscopy (ESR), Raman and in situ FTIR spectroscopic analysis provided direct evidence for the involvement of superoxide radical bound FeIII species in the oxidation reaction. Both the analysis suggested the end-on binding of superoxide radical with FeIII-centre. The stability of such radical bound FeIII-species in halloysite nanotube was analyzed through density functional theory (DFT) calculations. Results suggested that end-on (η1) binding was favourable by 13.5 kcal/ mol than the side-on (η2) binding mode. The formation of such reactive species was believed to play the crucial role in bringing the high selectivity in the catalytic oxidation of benzyl alcohol and oxidative C[sbnd]C coupling of 2-naphthol. UV–Vis spectroscopic studies on the oxidation of benzyl alcohol suggested for the initial adsorption of substrate molecule on the catalyst surface followed by its interaction with FeIII -superoxide/hydroperoxide species generated upon photoirradiation with visible light in presence of O2. The presence of a suitable band gap ～2.14 eV enabled the catalyst to catalyze the reaction under visible light irradiation. Both the reactions (benzyl alcohol and 2-naphthol oxidation) were tested in presence of both O2 and H2O2 as oxidants at ambient temperature. The influence of different parameters like rate of oxygen flow, amount of peroxide, nature of solvent, and catalyst amount on the conversion and selectivity of the reactions were studied to understand their role in the catalytic reactions. Successful oxidation of 2-naphthol with H2O2 as oxidant was a real success to overcome the limitations associated with this reaction using H2O2 as oxidant.
- Bania, Kusum K.,Baruah, Manash J.,Bora, Tonmoy J.,Dutta, Rupjyoti,Guha, Ankur Kanti,Roy, Subhasish
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- A Synergistic Magnetically Retrievable Inorganic-Organic Hybrid Metal Oxide Catalyst for Scalable Selective Oxidation of Alcohols to Aldehydes and Ketones
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Herein, we report a synergistic silica coated magnetic Fe3O4 catalyst functionalized with nitrogen rich organic moieties and immobilized with cobalt metal ion (FNP-5) for selective oxidation of alcohols to aldehydes and ketones using tert-butyl hydroperoxide (TBHP) as oxidant. The catalyst was rigorously characterized via several techniques which delineate its core-shell structure, magnetic behavior, phase and crystal structure. The Co(III) acts as the active catalytic center for selective oxidation reaction. The control reactions revealed radical mechanistic pathway assisted by the synergism induced by the inorganic-organic hybrid nature of FNP-5. The other features of current protocol involve neat reaction conditions, high TOF values, scalability of product and low E-factor value (1.92). Moreover, FNP-5 could be effortlessly separated via an external magnet, displays recyclability over eight catalytic cycles and exhibits structural integrity even after rigorous use. Overall, these results manifest the understanding of synergistic architectures as sustainable surrogates for selective oxidation reactions.
- Mittal, Rupali,Awasthi, Satish Kumar
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p. 4799 - 4813
(2021/09/30)
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- A novel two-dimensional metal-organic framework as a recyclable heterogeneous catalyst for the dehydrogenative oxidation of alcohol and theN-arylation of azole compounds
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A novel metal-organic framework (MOF) with two-dimensional (2D) crystal structure was developed using Cu(NO3)2·3H2O and 2,2′,5,5′-tetramethoxy-[1,1′-biphenyl]-4,4′-dicarboxylic acid. Further, its structure was characterized using infrared spectroscopy, thermogravimetry, X-ray diffraction, and X-ray crystallography. The activated Cu-MOF was used to catalyze the dehydrogenative oxidation of alcohol andN-arylation of azole compounds. Furthermore, it could be easily recovered and reused.
- Liu, Chengxin,Cui, Jin,Wang, Yufang,Zhang, Mingjie
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p. 11739 - 11744
(2021/03/31)
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- Synthesis, characterization, crystal structures, Hirshfeld surface analysis, DFT computational studies and catalytic activity of novel oxovanadium and dioxomolybdenum complexes with ONO tridentate Schiff base ligand
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For the first time, two new oxovanadium and dioxomolybdenum Schiff base complexes, VOL(OMe) and MoO2L, were synthesized through the reaction of a ONO tridentate Schiff base ligand (H2L) derived from the condensation of 5-bromosalicyl
- Kargar, Hadi,Bazrafshan, Maryam,Fallah-Mehrjardi, Mehdi,Behjatmanesh-Ardakani, Reza,Rudbari, Hadi Amiri,Munawar, Khurram Shahzad,Ashfaq, Muhammad,Tahir, Muhammad Nawaz
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- Selective oxidation of benzyl alcohols to benzaldehydes catalyzed by dioxomolybdenum Schiff base complex: synthesis, spectral characterization, crystal structure, theoretical and computational studies
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A novel dioxomolybdenum Schiff base complex, MoO2L·DMF, was synthesized by treating MoO2(acac)2 with an ONO donor Schiff base ligand (H2L) derived by the condensation of 4-aminobenzohydrazide and 3-methoxysalicy
- Kargar, Hadi,Fallah-Mehrjardi, Mehdi,Behjatmanesh-Ardakani, Reza,Munawar, Khurram Shahzad,Ashfaq, Muhammad,Tahir, Muhammad Nawaz
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p. 437 - 455
(2021/05/13)
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- Novel oxovanadium and dioxomolybdenum complexes of tridentate ONO-donor Schiff base ligand: Synthesis, characterization, crystal structures, Hirshfeld surface analysis, DFT computational studies and catalytic activity for the selective oxidation of benzyl
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Two new oxovanadium and dioxomolybdenum Schiff base complexes, [VvO(L)(OCH3)(CH3OH)] and [MoVIO2(L)(CH2CH3OH)], were synthesized by treating an ONO-donor type Schiff base ligand
- Amiri Rudbari, Hadi,Ashfaq, Muhammad,Behjatmanesh-Ardakani, Reza,Fallah-Mehrjardi, Mehdi,Forootan, Pooran,Kargar, Hadi,Nawaz Tahir, Muhammad,Shahzad Munawar, Khurram
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- Synthesis, spectral characterization, SC-XRD, HSA, DFT and catalytic activity of a dioxidomolybdenum complex with aminosalicyl-hydrazone Schiff base ligand: An experimental and theoretical approach
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A new dioxidomolybdenum(VI) complex has been successfully prepared by the reaction of an ONO donor Schiff base, derived by condensing 4-amino-2-hydroxybenzohydrazide and 3-methoxysalicylaldehyde, with MoO2(acac)2. The structures of s
- Kargar, Hadi,Fallah-Mehrjardi, Mehdi,Behjatmanesh-Ardakani, Reza,Munawar, Khurram Shahzad,Ashfaq, Muhammad,Tahir, Muhammad Nawaz
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- An aerobic oxidation of alcohols into carbonyl synthons using bipyridyl-cinchona based palladium catalyst
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We have reported an aerobic oxidation of primary and secondary alcohols to respective aldehydes and ketones using a bipyridyl-cinchona alkaloid based palladium catalytic system (PdAc-5) using oxygen at moderate pressure. ThePdAc-5catalyst was analysed using SEM, EDAX, and XPS analysis. The above catalytic system is used in experiments for different oxidation systems which include different solvents, additives, and bases which are cheap, robust, non-toxic, and commercially available on the industrial bench. The obtained products are quite appreciable in both yield and selectivity (70-85%). In addition, numerous important studies, such as comparisons with various commercial catalysts, solvent systems, mixture of solvents, and catalyst mole%, were conducted usingPdAc-5. The synthetic strategy of oxidation of alcohol into carbonyl compounds was well established and all the products were analysed using1H NMR,13CNMR and GC-mass analyses.
- Cheedarala, Ravi Kumar,Chidambaram, Ramasamy R.,Siva, Ayyanar,Song, Jung Il
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p. 32942 - 32954
(2021/12/02)
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- Selective aerobic oxidation of benzylic and allylic alcohols catalyzed by Cu(OAc)2/TEMPO/Et2NH
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Selective oxidation of benzylic and allylic alcohols to their corresponding aldehyde/ketone derivative without affecting saturated alcohols is still a challenging endeavor in organic synthesis. Various metal complexes, especially the copper complexes in the presence of TEMPO are being used very often for such transformations under aerobic conditions, but they are not selective to allylic and benzylic alcohols. The use of copper salt for oxidation of alcohols in the absence of a ligand are very scarcely studied except for the one catalyzed by CuCl/TEMPO where chloride inhibition and lack of selective oxidation have been noted upon use of CuCl2. Herein we report a Cu(OAc)2 catalyzed and TEMPO mediated selective aerobic oxidation of benzylic and allylic alcohols to aldehyde/ketone in the presence of Et2NH. The method avoids pre-synthesis of the catalyst as in the case of Cu(II)/(I) complexes/TEMPO catalyzed oxidation reactions, requires low catalyst loading, employs cheaper copper salt, and gives excellent selectivity for oxidation of benzylic and allylic alcohols.
- Bez, Ghanashyam,Gogoi, Achinta,Pasupuleti, Bala Gangadhar
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p. 589 - 597
(2021/09/28)
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- Introduction of a trinuclear manganese(iii) catalyst on the surface of magnetic cellulose as an eco-benign, efficient and reusable novel heterogeneous catalyst for the multi-component synthesis of new derivatives of xanthene
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In this work, the new trinuclear manganese catalyst defined as Fe3O4@NFC@NNSM-Mn(iii) was successfully manufactured and fully characterized by different techniques, including FT-IR, XRD, TEM, SEM, EDX, VSM, and ICP analysis. There have been reports of the use of magnetic catalysts for the synthesis of xanthine derivatives. The critical potential interest in the present method include short reaction time, high yields, recyclability of the catalyst, easy workup, and the ability to sustain a variety of functional groups, which give economical as well as ecological rewards. Also, the synthesized catalyst was used as a recyclable trinuclear catalyst in alcohol oxidation reactions at 40 °C. The magnetic catalyst activity of Fe3O4@NFC@NNSM-Mn(iii) could be attributed to the synergistic effects of the catalyst Fe3O4@NFC@NNS-Mn(iii) with melamine. Employing a sustainable and safe low temperature, using an eco-friendly solvent, no need to use any additive, and long-term stability and magnetic recyclability of the catalyst for at least six successive runs are the advantages of the current protocol towards green chemistry. This protocol is a benign, environmentally friendly method for heterocycle synthesis. This journal is
- Ghamari Kargar, Pouya,Bagherzade, Ghodsieh,Eshghi, Hossein
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p. 4339 - 4355
(2021/02/03)
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- Robust, highly active, and stable supported Co(ii) nanoparticles on magnetic cellulose nanofiber-functionalized for the multi-component reactions of piperidines and alcohol oxidation
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The new recyclable cobalt three-core magnetic catalyst obtained by anchoring a Schiff base ligand sector and cellulose nanofiber slings on MNP (Fe3O4) was prepared and named as MNP@CNF@ATSM-Co(ii). Separately, MNPs and CNF have adsorbent properties of great interest. In this way, this catalyst was designed to synthesize piperidine derivatives under solvent-free conditions and alcohol oxidation reactions in EtOH as the solvent. It should be noted that this catalyst is environmentally safe and does not need an external base. This MNPs@CNF@ATSM-Co(ii) separable catalyst has been evaluated using various characterization techniques such as FT-IR, XRD, FE-SEM, EDX, EDS, ICP, TGA, DLS, HRTEM, and VSM. The catalyst was compatible with a variety of benzyl alcohols, benzaldehydes, and amines derivatives, and gave complimentary coupling products with sufficient interest for all of them. The synergistic performance of Co (trinuclear) in the catalyst was demonstrated and its different homologs such as MNPs, MNPs@CNF, MNPs@CNF@ATS-Co(ii), and MNPs@CNF@ATSM-Co(ii) were separately synthesized and applied to a model reaction, and then their catalytic activity was investigated. Also, the performance of these components for the oxidation reaction of alcohols was evaluated. The advantages of the current protocol include the use of a sustainable and safe low temperature, eco-friendly solvent no additive, and long-term stability and magnetic recyclability of the catalyst for at least five successive runs, thus following green chemistry principles. This protocol is a benign and environment-friendly method for oxidation and heterocycle synthesis. This powerful super-magnetic catalyst can use its three arms to advance the reactions, displaying its power for multi-component reactions and oxidation.
- Bagherzade, Ghodsieh,Ghamari Kargar, Pouya
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p. 23192 - 23206
(2021/07/13)
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- SBA-15 Supported Silver Catalyst for the Efficient Aerobic Oxidation of Toluene Under Solvent-Free Conditions
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The efficient SBA-15 supported silver catalysts(Ag/SBA-15) were prepared and characterized by ICP-OES, XRD, TEM, SEM, XPS and N2 adsorption–desorption techniques. The catalysts exhibited an excellent catalytic activity for the aerobic oxidation of toluene to benzaldehyde under solvent-free conditions. Conversion of toluene and selectivity of benzaldehyde were 50% and 89% respectively over catalyst with 9.1 wt% Ag loading (10Ag/SBA-15). A wide range of substrates were tolerated under the selected reaction conditions. The kinetic study shows that the oxidation of toluene over 10Ag/SBA-15 is pseudo-first-order reaction and the activation energy Ea is 45.1?kJ/mol. A plausible mechanism involving oxygen free radicals was proposed for the aerobic oxidation reaction. Compared with the traditional method, the newly designed heterogeneous catalytic system shows better economic applicability, environmental friendliness and broader application prospects. Graphical abstract: [Figure not available: see fulltext.]
- Chen, Lei,Chen, Yanjiao,Dai, Xuan,Guo, Jiaming,Peng, Xinhua
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- Core-shell Co-MOF-74@Mn-MOF-74 catalysts with Controllable shell thickness and their enhanced catalytic activity for toluene oxidation
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A series of core-shell Co-MOF-74@Mn-MOF-74 samples with different shell thicknesses were prepared by the seed growth method, which were characterized by powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), inductively coupled plasma mass spectrometry (ICP-MS), X-ray photoelectron spectroscopy, nitrogen adsorption-desorption and scanning electron microscopy (SEM). The shell thickness of these MOF samples were successfully controlled by adjusting the mass ratio between MnCl2·4H2O and Co-MOF-74. On this basis, these MOFs were applied to the catalytic oxidation of toluene. The results showed that with the growth of Mn-MOF-74 in the outer layer of Co-MOF-74, the oxidative selectivity of the substrate to benzaldehyde was greatly improved for the synergy between the core layer and shell layer. The conversion of toluene was 22.4%, and the selectivity of benzaldehyde was 98.1%. In addition, the catalyst can transform various substituted toluene into the corresponding aldehydes in highly selectivity and still keep good stability after four catalytic cycles. The selectivity of the corresponding aldehyde is generally above 80%.
- Gu, Xiangyu,Huang, Cheng,Xu, Zengchuang,Wu, Hao,Dong, Ruilan,Liu, Rui,Chen, Jing,Zhu, Hongjun
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- Preparation method of o-nitrobenzaldehyde
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The invention relates to the technical field of organic synthesis, in particular to a preparation method of o-nitrobenzaldehyde. The invention provides a preparation method of o-nitrobenzaldehyde, which comprises the following steps: (A) carrying out oxidation reaction on o-nitroethylbenzene to obtain 1-(2-nitrophenyl)ethanol; (B) carrying out oxidation reaction on the 1-(2-nitrophenyl)ethanol to obtain o-nitroacetophenone; (C) carrying out oxidation reaction on the o-nitroacetophenone to obtain the o-nitrobenzaldehyde. According to the preparation method, cheap o-nitroethylbenzene is taken as a raw material, and o-nitrobenzaldehyde is obtained through three steps of oxidation reactions under different conditions. The method is reasonable in route, few in side reaction, high in yield, simple to operate, mild in reaction condition, low in equipment requirement and suitable for large-scale industrial production.
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- Intermediate substance with acid degradation function, preparation method of same, and polymerizable monomer prepared from intermediate substance
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The invention discloses an intermediate substance with an acid degradation function and a preparation method of same; whereinthe preparation method of the intermediate substance comprises the following steps: dissolving 2-nitrobenzaldehyde in a proper amount of dichloromethane, if the reaction substance is cinnamyl aldehyde, mixing the substance with trimethyl orthoformate without the help of a dichloromethane solvent with hafnium trifluoromethanesulfonate as a catalyst; then under the condition of room temperature, performing magnetic stirring to obtain the target substance in a very short time. According to the invention, the defects of time consumption, energy consumption, solvent consumption and the like caused by adopting p-toluenesulfonic acid as a catalyst for preparing the substance traditionally are avoided, and the prepared substance has an acid degradation function. Corresponding 2-nitrobenzaldehyde or cinnamyl aldehyde can be obtained through acid degradation, and in addition, the intermediate substance provides convenience for subsequent preparation of polymerizable monomers with an acid degradation function.
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Paragraph 0062; 0065
(2021/11/27)
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- The: In situ fabrication of ZIF-67 on titania-coated magnetic nanoparticles: A new platform for the immobilization of Pd(ii) with enhanced catalytic activity for organic transformations
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Considering the outstanding characteristics of metal organic frameworks (MOFs) and magnetic nanoparticles, herein we report a facile approach for the synthesis of a magnetic zeolitic-imidazolate-framework-supported palladium(ii) catalyst. In brief, zeolitic imidazolate framework-67 (ZIF-67) was successfully incorporated onto the surface of titania-coated magnetic nanoparticles using ethane-1,2-diamine as a linker, and then Pd(ii) was immobilized onto this. The resulting Pd@ZIF-67-Fe3O4-TiO2 catalyst possesses a high surface area (205 m2 g-1), a large pore volume (0.10 cm3 g-1), good magnetic responsivity (10.71 emu g-1), and high stability. A comparative analysis of Pd@ZIF-67-Fe3O4-TiO2 and Pd@Fe3O4-TiO2 catalysts for the oxidation, reduction, and oxidative deprotection of oximes was done to investigate the effects of ZIF-67 on the catalytic performance of Pd species. Substantial differences in activity and stability were observed in the presence of ZIF-67, suggesting that ZIF-67 plays an important role in enhancing the activity of Pd(ii). This superior catalytic activity and stability arises due to a synergistic effect between well-dispersed palladium species and highly porous ZIF-67, which was confirmed via XPS analysis. Moreover, the catalyst retains its structure, chemical environment, and good magnetic response even after five catalytic runs, as confirmed via FTIR, XRD, XPS, and VSM studies of reused catalyst samples.
- Kaur, Manpreet,Paul, Satya,Sharma, Chandan,Sharma, Sukanya
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p. 20309 - 20322
(2021/11/22)
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- Preparation method of O-nitrobenzaldehyde
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The invention relates to a preparation method of o-nitrobenzaldehyde, which comprises the following steps: preparing 1,2-bis(o-nitrophenyl)ethylene by using required products nitrobenzaldehyde and nitrotoluene as raw materials, and carrying out high-efficiency oxidation by using ozone with proper concentration to obtain the final product nitrobenzaldehyde. The preparation method has the beneficialeffects that only a proper amount of alkali is used for catalysis in the condensation reaction, and the intermediate product 1,2-bis(o-nitrophenyl)ethylene can be efficiently obtained by using a conventional solvent to carry out a reaction with water; a gas-liquid reaction then is carried out by using a micro-channel reactor to finally obtain the required nitrobenzaldehyde. The method has the advantages of low use amount of raw materials, high reaction yield, few byproducts and impurities, simple and feasible purification operation and convenience for industrial production in workshops.
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Paragraph 0030; 0033; 0034; 0037; 0038; 0042
(2020/02/14)
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- Preparation method and application of O-nitrobenzaldehyde
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The invention relates to a preparation method of o-nitrobenzaldehyde. The preparation method comprises the following steps: reacting o-nitrobenzyl triphenylphosphonium bromide with the required product o-nitrobenzaldehyde as raw materials to generate 1, 2-bis (o-nitrophenyl) ethylene, and oxidizing with ozone to obtain o-nitrobenzaldehyde. The preparation method has the beneficial effects that only a proper amount of alkali is used for catalysis in a condensation reaction, and an intermediate product 1, 2-bis (o-nitrophenyl) ethylene can be efficiently obtained by catalysis of an alkaline water reaction; and gas-liquid reaction is performed by using a micro-channel reactor to finally obtain the required nitrobenzaldehyde. The method has the advantages of less used raw materials, high reaction yield, less by-products and impurities, simple and feasible purification operation, and convenience for industrial production in workshops. Under the condition that the current chemical engineering environment protection and safety situation is severe, the process route can stably supply the important chemical intermediates of the type in an environment-friendly mode with the extremely high atom utilization rate.
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Paragraph 0038; 0041; 0042; 0045
(2020/09/23)
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- Visible-light mediated facile dithiane deprotection under metal free conditions
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Visible light mediated facile and selective dithiane deprotection under metal free conditions is developed. Eosin Y (1 mol%) proved to be an effective catalyst for the dithiane deprotection under the ambient photoredox conditions. The standard household compact fluorescent light source (CFL bulb) proved to be effective under open-air conditions in aqueous acetonitrile at room temperature. The protocol that exhibits a broad substrate scope and functional group tolerance has been shown to expand to a range of transformations for the electron-rich and -deficient thioacetals and thioketals. The synthetic utility of this protocol has also been demonstrated by gram-scale application.
- Dharpure, Pankaj D.,Bhowmick, Anindita,Warghude, Prakash K.,Bhat, Ramakrishna G.
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- One-pot, oxidative and selective conversion of benzylic silyl and tetrahydropyranyl ethers to gem-dichlorides using trichloroisocyanuric acid and triphenylphosphine as an efficient and neutral system
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A one-pot and oxidative method is described for the first time for the conversion of benzylic trimethylsilyl (TMS) and tetrahydropyranyl (THP) ethers to gem-dichlorides using trichloroisocyanuric acid (TCCA) and triphenylphosphine (PPh3) in neutral media. Various theses substrates containing electron withdrawing or donating groups can be efficiently converted to their corresponding gem-dichlorides in good to excellent yields. The present method shows a high degree of chemoselectivity, and due to its one-pot nature is in accordance with green chemistry.
- Khadem Moghaddam, Roqayeh,Aghapour, Ghasem
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p. 398 - 406
(2020/11/19)
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- Divergent Syntheses of Indoles and Quinolines Involving N1-C2-C3 Bond Formation through Two Distinct Pd Catalyses
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Pd-catalyzed annulative couplings of 2-alkenylanilines with aldehydes using alcohols as both the solvent and hydrogen source have been developed. These domino processes allow divergent syntheses of two significant N-heterocycles, indoles and quinolines, from the same substrate by tuning reaction parameters, which seems to invoke two distinct mechanisms. The nature of the ligand and alcoholic solvent had a profound influence on the selectivity and efficiency of these protocols. Particularly noteworthy is that indole formation was achieved by overcoming two significant challenges, regioselective hydropalladation of alkenes and subsequent reactions between the resulting Csp3-Pd species and less reactive imines.
- San Jang, Su,Kim, Young Ho,Youn, So Won
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p. 9151 - 9157
(2020/11/03)
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- A tunable synthesis of either benzaldehyde or benzoic acid through blue-violet LED irradiation using TBATB
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In this paper, a highly efficient, metal-free, and homogeneous method for the selective aerobic photooxidation of alcohols and photooxidative-desilylation of tert-butyldimethylsilyl ethers (TBDMS) in the presence of tetrabutylammonium tribromide (TBATB) under irradiation of visible light was reported. The light source: blue (460 nm) and violet (400 nm) LED, can control selective oxidation to aldehyde or carboxylic acid.
- Mardani, Atefeh,Heshami, Marouf,Shariati, Yadollah,Kazemi, Foad,Abdollahi Kakroudi, Mazaher,Kaboudin, Babak
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- IBX-TfOH mediated oxidation of alcohols to aldehydes and ketones under mild reaction conditions
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An efficient, practical and facile procedure has been developed for the oxidation of primary and secondary alcohols using IBX-TfOH catalytic system in 1,4-dioxane at ambient temperature. The reaction affords quantitative yields of the corresponding carbonyl compounds without the formation of over oxidized products. The present synthetic protocol is compatible with a variety of substrates having arene, heteroarene and alkene functionalities. The developed synthetic protocol can be used for higher scale reactions as evident by the oxidation of alcohol at 1 g scale in higher yields by a simple filtration process.
- Kumar, Kamlesh,Kumar, Prashant,Joshi, Penny,Rawat, Diwan S
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supporting information
(2020/03/04)
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- Green synthesis and characterization of novel Mn-MOFs with catalytic and antibacterial potentials
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This study focused on the synthesis of a new manganese-based metal-organic framework and the investigation of its application aspects. A Mn-MOF nanostructure, namely UoB-4, was prepared using a Schiff base organic linker (H2bbda: 4,4′-[benzene-
- Aryanejad, Sima,Bagherzade, Ghodsieh,Moudi, Maryam
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p. 1508 - 1516
(2020/02/06)
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- Magnetic nanoparticle supported ionic liquid phase catalyst for oxidation of alcohols
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Anew magnetic nanoparticle supported ionic liquid phase (SILP) catalyst containing perruthenate anions was prepared by a multistep procedure. The various analytical techniques such as FT-IR spectroscopy, X-ray photoelectron spectroscopy, transmission elec
- Naikwade, Altafhusen,Jagadale, Megha,Kale, Dolly,Rashinkar, Gajanan
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p. 1088 - 1097
(2020/10/20)
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- Simple synthesis of the novel Cu-MOF catalysts for the selective alcohol oxidation and the oxidative cross-coupling of amines and alcohols
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A novel porous metal–organic framework {Cu2(bbda)0.5(Hbbda)1.5(OAc)1.5.8H2O} (UoB-5) was synthesized under ultrasound irradiation by employing a new Schiff base ligand H2bbda (4,4'(1,4-phenylene bis (azanylylidene)) bis (methanylylidene))dibenzoic acid) and was fully characterized. The microporous nature of UoB-5 was confirmed by gas-sorption measurements. This framework acted as a highly effective heterogeneous catalyst for the alcohol oxidation reaction with tert-butyl hydroperoxide (t-BuOOH) as an oxidant. The presence of coordinatively unsaturated metal sites in UoB-5 could be the reason for high performance in this reaction. Furthermore, using the long linker with the free -NC group and uncoordinated -N atom on the wall of the pores created UoB-5 an excellent candidate for the catalytic activities without activation of the framework. It was confirmed with the heterogeneous catalytic experiments on the one-pot tandem synthesis of imines from benzyl alcohols and anilines. Eventually, the new Cu-MOF (UoB-5) could be an alternative catalyst as a more economically favorable and environmentally friendly in the catalysis field.
- Ghamari Kargar, Pouya,Aryanejad, Sima,Bagherzade, Ghodsieh
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- Visible-light assisted of nano Ni/g-C3N4 with efficient photocatalytic activity and stability for selective aerobic C?H activation and epoxidation
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A selective, economical, and ecological protocol has been described for the oxidation of methyl arenes and their analogs to the corresponding carbonyl compounds and epoxidation reactions of alkenes with molecular oxygen (O2) or air as a green oxygen source, under mild reaction conditions. The nano Ni/g-C3N4 exhibited high photocatalytic activity, stability, and selectivity in the C?H activation of methyl arenes, methylene arenes, and epoxidation of various alkenes under visible- light irradiation without the use of an oxidizing agent and under base free conditions.
- Akrami, Zahra,Hosseini-Sarvari, Mona
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supporting information
(2020/10/13)
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- Preparation method of O-nitrobenzaldehyde
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The invention provides a preparation method of o-nitrobenzaldehyde. The method is characterized by comprising the following steps of: adding o-nitrotoluene and an alcohol solvent into a reactor, continuously stirring, and controlling the temperature to be 20 to 30 DEG C; dropwise adding liquid bromine, and carrying out catalytic reaction for 5-30 min by using ultraviolet light; adding a sodium bicarbonate solution, and carrying out heating to reflux; and adjusting temperature to room temperature, and carrying out extraction, drying, concentration and recrystallization to obtain the product o-nitrobenzaldehyde. According to the method, ultraviolet light is adopted as a catalyst, a mixed solvent of water and alcohol is adopted for recrystallization, the yield of the obtained product is greater than 80%, and the purity of the obtained product is greater than 99%.
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Paragraph 0027-0038
(2020/10/14)
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- A Remote ‘Imidazole’-Based Ruthenium(II) Para-Cymene Pre-catalyst for the Selective Oxidation Reaction of Alkyl Arenes and Alcohols
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Herein we disclosed the use of a remote ‘imidazole’-based precatalyst [(para-cymene)RuII(L)Cl]+, C-1 where L=2-(4-substituted-phenyl)-1H-imidazo[4,5-f][1,10] phenanthroline) for the selective oxidation of a variety of alkyl arenes/heteroarenes and alcohols to their corresponding aldehydes or ketones in presence of tert-butyl hydroperoxide (TBHP). The remote ‘imidazole’ moiety present in the complex facilitates the activation of oxidant and subsequent generation of active species via the release of para-cymene from C-1, which in-turn was less effective without the ‘imidazole’ moiety. The mechanistic features of C-1 promoted oxidation of alkyl arenes were also assessed from spectroscopic, kinetic, and few control experiments. The substrate scope for C-1 promoted oxidation reaction was assessed based on the selective oxidation of 27-different alkyl arenes/heteroarenes and 25 different alcohols to their corresponding aldehydes/ketones in moderate to good yields.
- Dutta, Manali,Bania, Kusum K.,Pratihar, Sanjay
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p. 926 - 932
(2020/03/05)
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- KMnO4-catalyzed chemoselective deprotection of acetate and controllable deacetylation-oxidation in one pot
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A novel and efficient protocol for chemoselective deacetylation under ambient conditions was developed using catalytic KMnO4. The stoichiometric use of KMnO4 highlighted the dual role of a heterogeneous oxidant enabling direct access to aromatic aldehydes in one-pot sequential deacetylation-oxidation. The reaction employed an alternative solvent system and allowed the clean transformation of benzyl acetate to sensitive aldehyde in a single step while preventing over-oxidation to acids. Use of inexpensive and readily accessible KMnO4 as an environmentally benign reagent and the ease of the reaction operation were particularly attractive, and enabled the controlled oxidation and facile cleavage of acetate in a preceding step. This journal is
- Gurawa, Aakanksha,Kumar, Manoj,Rao, Dodla S.,Kashyap, Sudhir
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supporting information
p. 16702 - 16707
(2020/10/27)
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- Visible light photoredox catalyzed deprotection of 1,3-oxathiolanes
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An efficient visible light photoredox catalyzed aerobic deprotection of 1,3-oxathiolanes using organic dye Eosin Y as a photocatalyst is disclosed. The deprotection procedure features the use of a metal-free catalyst, mild conditions, a broad range of substrate scope, and good functional group tolerance. 35 examples were tested under the standard conditions and most of them afforded the deprotected products in modest to high yields.
- Yang, Mingyang,Xing, Zhimin,Fang, Bowen,Xie, Xingang,She, Xuegong
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supporting information
p. 288 - 291
(2020/01/13)
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- Synthesis and photochemical studies of 2-nitrobenzyl-caged N-hydroxysulfonamides
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Recently, N-hydroxysulfonamides (RSO2NHOH) caged by photolabile protecting groups have attracted significant interest as potential photoactive nitroxyl (HNO) donors. The selectivity of the desired HNO generation pathway from photocaged N-hydroxysulfonamides versus a competing pathway involving O-N bond cleavage is dependent on the specific photodeprotection mechanism of the phototrigger. We present a new class of photocaged N-hydroxysulfonamides incorporating the well-established o-nitrobenzyl photoprotecting group, including a derivative incorporating an additional carbonate linker. Photodecomposition of o-NO2Bn-ON(H)SO2CF3 and the corresponding 2-nitro-4,5-dimethoxybenzyl analog generated the desired HNO and CF3SO2- as a minor pathway, with competing photoinduced O-N bond cleavage to release CF3SO2NH2 as the major photodecomposition pathway. Photolysis of the corresponding -SO2CH3 analogs resulted in O-N bond cleavage only. The presence of the o-nitro substituent was shown to be essential for photoactivity. Photorelease of the parent HNO donor CH3SO2NHOH was observed as the major product upon irradiation of o-NO2Bn-OC(O)ON(H)SO2CH3, with the desired HNO release and O-N bond cleavage occurring as minor pathways. Photoproduct quantum yields for each species have been determined by actinometry. The effect of solvent, pH and air on the mechanism of photodecomposition was studied for o-NO2Bn-ON(H)SO2CH3. The ratio of the solvents in the solvent mixture (CH3CN and phosphate buffer, pH 7.0), the pH of the aqueous component of the buffer, and the presence of oxygen did not affect the amount of each photoproduct and the observed rate constant for O-N bond cleavage. Possible mechanisms for the various pathways are proposed.
- Zhou, Yang,Bharadwaj, Vinay,Rahman, Mohammad S.,Sampson, Paul,Brasch, Nicola E.,Seed, Alexander J.
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- A novel nano-cotton-like bismuth oxyfluoride (NC-BiOF) and a novel nanosheet heterogeneous compound BiOF@ZIF-8 as catalyst for the selective and green oxidation of benzylic alcohols
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We describe here for the first time a new morphology of BiOF nanoparticles with a cotton-like structure, made using a hydrothermal synthesis method. We also prepared heterogeneous nanosheets of BiOF@ZIF-8 by a one-pot synthesis under hydrothermal conditions. We demonstrate that in this method the morphology of BiOF and one-pot synthesis conditions are the main factors for the preparation of the nanosheet BiOF@ZIF-8. Fourier transform infrared (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), thermogravimetry-differential thermal analysis (TG-DTA), and BET surface area were used to characterize the samples prepared. XRD, SEM, and adsorption–desorption analysis showed that the structure of ZIF-8 and BiOF form intact only in one-pot synthesis of BiOF (with nano-cotton-like morphology) with Zn(NO3)3, while spectral techniques show the successful encapsulation of the sheet BiOF on ZIF-8. Nanosheet BiOF@ZIF-8 was found to be a highly efficient heterogeneous catalyst for the selective oxidation of alcohols. BiOF@ZIF-8 could be reused several times although it got less active with recycling.
- Ghayoumian, Narges,Aliyan, Hamid,Fazaeli, Razieh
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p. 363 - 370
(2018/10/26)
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- Design and development of novel Co-MOF nanostructures as an excellent catalyst for alcohol oxidation and Henry reaction, with a potential antibacterial activity
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The novel metal–organic framework Co2(bdda)1.5(OAc)1·5H2O (UoB-3) was synthesized via a simple method at room temperature. UoB-3 was characterized by the different methods, including X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), N2-adsorption/desorption and elemental analysis. The catalytic ability of UoB-3 was detected to be excellent for primary and secondary alcohols oxidation reaction with high yields under solvent-free conditions. Moreover, UoB-3 was highly active for Henry reaction of different aldehydes with nitromethane in water as a green solvent. The nanocatalyst can be recycled for five consecutive cycles without losing its activity and structural rigidity. The antibacterial activity of UoB-3 nanostructures towards Gram-negative bacteria, Escherichia coli and Gram-positive bacteria, Bacillus cereus was also evaluated by using an inhibition zone test. These nanostructures exhibited strong antibacterial effect against both of them. The purpose of this study was the developing metal–organic framework materials with the enhanced activity in various fields.
- Aryanejad, Sima,Bagherzade, Ghodsieh,Moudi, Maryam
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- Switchable Bifunctional Bistate Reusable ZnO-Cu for Selective Oxidation and Reduction Reaction
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Herein we disclosed the utilization of copper loaded zinc oxide (ZnO-Cu) for its stimuli (O2/light) responsive switchable performance between its reduced (S-1) and oxidized (S-2) state for two antagonistic reactions, namely oxidation of alkyl arenes/heteroarenes to aldehydes/ketones and reduction of nitro arenes/heteroarenes to corresponding amines. The two states of the catalyst showed its switchable performance as highly active and poorly active catalyst for oxidation and reduction, and both reactions could be turned "off" and "on" by changing the stimuli (light and O2/N2). The switching efficiency between the states and their relative reactivity were found to be consistent under variety of reaction conditions and remain unaltered irrespective of oxidation-reduction (or vice versa) sequence and substrates used in the reaction. The photo catalysts (S-1 and S-2) demonstrated good catalytic activity, multiple reusability, broad substrate scope, and reasonable functional group tolerance for both the reactions and probed its quality performance in a large-scale setup. The system was used in an assisted tandem catalysis setup for the synthesis of benzyl amines utilizing both oxidation and reduction reaction by stimuli responsive switching between the states of the catalyst.
- Sarmah, Kasturi,Mukhopadhyay, Subhamoy,Maji, Tarun K.,Pratihar, Sanjay
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p. 732 - 745
(2019/01/11)
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- Development of a polymer embedded reusable heterogeneous oxovanadium(IV)catalyst for selective oxidation of aromatic alkanes and alkenes using green oxidant
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A new heterogeneous polymer supported solid phase oxovanadium(IV)catalyst was synthesized successfully. The designed catalyst furnished excellent results in the oxidation reactions of various aromatic alkanes, e.g. toluene, para-xylene, mesitylene. The polymer supported vanadium complex was proved also an efficient catalyst for the oxidation of aromatic alkenes, like substituted styrenes, trans-stilbene, etc. under mild reaction conditions. The supported catalyst was nicely elucidated by SEM-EDAX, TGA, FT-IR and UV–Vis spectral analysis. The catalytic activity was tested in the presence of an environment-friendly oxidant, 30% aqueous H2O2 during the oxidation of broad range of substrates. Another important fact is that the designed oxovanadium(IV)catalyst is heterogeneous in nature. Moreover, the newly synthesized oxovanadium(IV)complex exhibited a notable recoverability and it could be recycled up to six runs devoid of any prominent reduction in catalytic behavior.
- Paul, Priyanka,Ghosh, Aniruddha,Chatterjee, Sauvik,Bera, Apurba,Alam, Seikh Mafiz,Islam, Sk. Manirul
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p. 198 - 212
(2019/05/01)
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- Preparation method of o-nitrobenzaldehyde
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The invention relates to a preparation method of o-nitrobenzaldehyde, and is mainly applied to the field of medicine synthesis. According to the method disclosed by the invention, o-nitrotoluene is taken as a raw material, an initiator is added and subjected to a bromination reaction with liquid bromine in an oil-water two-phase solvent, hydrolyzed by sodium carbonate, and oxidized by dilute nitric acid to obtain crude o-nitrobenzaldehyde, and finally purification and discoloration are performed to obtain white o-nitrobenzaldehyde with the purity is 99.9%.
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- Selective Visible Light Aerobic Photocatalytic Oxygenation of Alkanes to the Corresponding Carbonyl Compounds
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The aerobic, selective oxygenation of alkanes via C-H bond activation is an important research challenge. Photocatalysis offers the potential for the introduction of additional concepts for such reactions. Visible light photoactive semiconductors such as bismuth oxyhalides (BiOX, X = Cl and Br) used in this research typically oxidize organic compounds through photocatalyzed formation of strongly oxidizing holes. The reactive oxygen species formed react with organic compounds in one-electron processes, leading to radical intermediates and nonselective oxidation. Such oxidation reactions generally lead to total oxidation. Here, impregnation of BiOX with a polyoxometalate, H5PV2Mo10O40, as a strong electron acceptor changed the reactivity of BiOX, leading to Mars-van Krevelen-type reactivity, that is, photoactivated oxygen donation from BiOX to the organic substrate followed by reoxidation by O2 and catalysis. This conclusion was supported by mechanistic studies involving isotope labeling studies. In this way, ethane was selectively oxidized to acetaldehyde in a flow reactor with a turnover number (24 h) of 415.
- Somekh, Miriam,Khenkin, Alexander M.,Herman, Adi,Neumann, Ronny
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p. 8819 - 8824
(2019/09/30)
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- On/Off O2 Switchable Photocatalytic Oxidative and Protodecarboxylation of Carboxylic Acids
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Photoredox catalysis in recent years has manifested a powerful branch of science in organic synthesis. Although merging photoredox and metal catalysts has been a widely used method, switchable heterogeneous photoredox catalysis has rarely been considered. Herein, we open a new window to use a switchable heterogeneous photoredox catalyst which could be turned on/off by changing a simple stimulus (O2) for two opponent reactions, namely, oxidative and protodecarboxylation. Using this strategy, we demonstrate that Au@ZnO core-shell nanoparticles could be used as a switchable photocatalyst which has good catalytic activity to absorb visible light due to the localized surface plasmon resonance effect of gold, can decarboxylate a wide range of aromatic and aliphatic carboxylic acids, have multiple reusability, and are a reasonable candidate for synthesizing both aldehydes/ketones and alkane/arenes in a large-scale set up. Some biologically active molecules are also shown via examples of the direct oxidative and protodecarboxylation which widely provided pharmaceutical agents.
- Bazyar, Zahra,Hosseini-Sarvari, Mona
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p. 13503 - 13515
(2019/10/11)
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- Polymer-incarcerated palladium-catalyzed facile: In situ carbonylation for the synthesis of aryl aldehydes and diaryl ketones using CO surrogates under ambient conditions
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In this existing work, an efficient polymer-supported palladium catalyst, a furfurylamine-functionalized Merrifield complex of palladium [Pd@(Merf-FA)], was synthesized and characterized, showing excellent catalytic activity towards in situ carbonylation reactions using carbon monoxide surrogates like formic acid and chloroform. Herein, we examined the catalytic activity of the Pd@(Merf-FA) catalyst for the formylation of aryl iodides and carbonylative Suzuki-Miyaura coupling reactions. The Pd@(Merf-FA) catalyst was systematically characterized by several techniques like HRTEM, elemental mapping, PXRD, TGA-DTA, FESEM, UV-vis, EDAX, CHN and AAS analysis. The catalyst is highly recyclable, able to be recycled up to six times without showing any significant decrease in catalytic activity. The [Pd@(Merf-FA)] catalyst proved to be more efficient compared to the corresponding homogeneous palladium catalyst. In addition, the leaching experiment of the synthesized catalyst was studied, which showed that negligible leaching of metal occurred from the polymeric support.
- Dey, Tusar Kanto,Basu, Priyanka,Riyajuddin, Sk,Ghosh, Aniruddha,Ghosh, Kaushik,Manirul Islam, Sk
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p. 9802 - 9814
(2019/07/04)
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- Decarboxylative Benzylation of Aryl and Alkenyl Boronic Esters
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The copper-catalyzed decarboxylative benzylation of aryl and alkenyl boronic esters with electron-deficient aryl acetates is reported. The oxidative coupling proceeds under mild, aerobic conditions and tolerates a host of potentially reactive electrophilic functional groups that would be problematic with traditional benzylation methods (aryl iodides and bromides, protic heteroatoms, aldehydes, Michael acceptors). A reaction pathway in which a benzylic nucleophile is generated by aryl acetate decarboxylation and in turn is intercepted by the catalyst to form diarylmethane products is supported by mechanistic studies.
- Moon, Patrick J.,Fahandej-Sadi, Anis,Qian, Wenyu,Lundgren, Rylan J.
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supporting information
p. 4612 - 4616
(2018/03/26)
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- Pyrrolo[2,1-c][1,4] benzodiazepine-3,11-diones protect SHSY-5Y cells from Cd-induced apoptosis involving suppression of endoplasmic reticulum stress
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Cadmium (Cd) is a potent toxic heavy metal, some studies showed that Cd-induced apoptosis is through ER stress pathway. Compounds of pyrrolo[2,1–c][1,4]benzodiazepine (PBD)-3,11-diones were discovered as potent neuroprotective agents against Cd-induced toxicity in SH-SY5Y cells for the first time. In this study, twenty-six PBD-3,11-dione derivatives were synthesized and evaluated for their neuroprotective activity against Cd-induced toxicity by CCK-8 assay. Their preliminary SARs studies indicated that various substituents were tolerated on the benzene ring, and alkyl heterocycles groups at the N10-position of the PBD-3,11-dione scaffold were important for the activities. Among them, compound 13c exhibited the best activity (cell viability = 68.6%, 25 μM). Furthermore, we found that the compound 13c could inhibit cadmium-induced cell apoptosis with the downregulation of the ER stress markers GRP78, CHOP, cleaved-caspase12 and cleaved-caspase3 through western blotting. The results of in silico evaluation of ADME/T properties showed that 13c exhibited medium BBB penetration level and promising toxicity profiles. These results proved the potential of 13c as a promising lead compound against Cd-induced neurotoxicity.
- Ma, Chao,Du, Ke,Zhao, Ying,Zhang, Linkui,Hu, Baichun,Cheng, Maosheng
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p. 5151 - 5158
(2018/09/27)
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- Cu(II) Schiff base complex supported on Fe3O4 nanoparticles as an efficient nanocatalyst for the selective aerobic oxidation of alcohols
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Herein, we have prepared a new Cu(II) Schiff base complex supported onto the surface of modified Fe3O4 nanoparticles as highly stable, heterogeneous and magnetically recyclable nanocatalyst for the selective aerobic oxidation of different alcohols. The structure, morphology, chemical composition and magnetic property of the nanocatalyst and its precursors were characterized using FT-IR, TGA, AAS, ICP-AES, XRD, SEM, EDS, VSM and N2 adsorption–desorption analyses. Characterization results exhibited the uniform spherical morphology for nanocatalyst and its precursors. A promising eco-friendly method with short reaction time and high conversion and selectivity for oxidation of various primary and secondary alcohols under O2 atmosphere condition was achieved. The synthesized nanocatalyst could be recovered easily by applying an external magnetic field and reused for least eight subsequent reaction cycles with only negligible deterioration in catalytic performance.
- Aghajani, Milad,Monadi, Niaz
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