- Natural bentonite clay/dilute HNO3 (40%) - A mild, efficient, and reusable catalyst/reagent system for selective mono nitration and benzylic oxidations
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Selective mono nitration of Aromatic hydrocarbons and benzylic oxidations can be achieved in high yield using reusable catalyst/reagent system consisting of bentonite clay and dilute HNO3 under relatively mild experimental conditions. The dual behavior of the catalyst reagent system is utilized for the regioselective synthesis of a variety of industrially important compounds.
- Bahulayan, Damodaran,Narayan, Gopinathan,Sreekumar, Vellalath,Lalithambika, Malathy
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- Nitration of aromatic compounds by Zn(NO3)2· 2N2O4 and its charcoal-supported system
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Zn(NO3)2·N2O4 and its charcoal supported system were found to be efficient nitrating agents. Mononitration of aromatic compounds such as benzene, alkyl benzenes, halobenzenes, nitrobenzene, anisol, and the highly selective mono-, di-, and trinitration of phenol, and dinitraion of substituted phenols were also performed in the presence of these reagents.
- Iranpoor, Nasser,Firouzabadi, Habib,Heydari, Reza,Shiri, Morteza
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- Polymer-supported ytterbium perfluorooctanesulfonate [Yb(OPf)3]: A recyclable catalyst for organic reactions
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Amberlyst A-21, a kind of well-known and cheap polymeric material, was treated with ytterbium perfluorooctanesulfonate [Yb(OPf)3] giving a reagent with a ytterbium loading of 1.34 (wt%). The polymer-supported fluorous ytterbium catalyses the highly efficient nitration, esterification, Fridel-Crafts acylation, and aldol condensation. The catalyst can be recovered by simple filtration and used again without a significant loss of catalytic activity. The protocol avoids the use of fluorous solvents during the reaction or workup, which are expensive and can leach in small amounts.
- Yi, Wen-Bin,Cai, Chun
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- Paradigm confirmed: The first use of ionic liquids to dramatically influence the outcome of chemical reactions
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It has been an unproven paradigm that the choice of which ionic liquid to use in a chemical reaction can have a dramatic effect on the outcome of that chemical reaction. We demonstrate, for the first time, that the reaction of toluene and nitric acid in three different ionic liquids gives rise to three completely different products in high yield. Furthermore, ionic liquids can catalyze these reactions with the only byproduct being water.
- Earle, Martyn J.,Katdare, Suhas P.,Seddon, Kenneth R.
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- Preparation of heteropoly acid based amphiphilic salts supported by nano oxides and their catalytic performance in the nitration of aromatics
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A series of Keggin heteropoly acid anion based amphiphilic salts supported by nano oxides were synthesized and used as catalysts in the nitration of aromatic compounds with HNO3. The reaction conditions in the nitration of toluene were optimized and both 92.6% conversion and good para selectivity (ortho:para = 1.09) were obtained.
- Wang, Peng-Cheng,Yao, Kai,Lu, Ming
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- STIMULATION BY Sn(2+) OR ASCORBIC ACID ON DIAZONIUM SALTS REACTIONS
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Use of a mild reducing agent and ligand transfer for the transformation of diazonium salts into aryl halides provides an alternative to the Sandmeyer procedure.
- Galli, Carlo
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- Silver-catalysed protodecarboxylation of ortho-substituted benzoic acids
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Catalytic amounts of Ag(i) salts in DMSO have been found to promote the protodecarboxylation of a wide variety of ortho-substituted benzoic acids under mild conditions and in excellent yields, highlighting a possible role for silver in decarboxylative cross-couplings. The Royal Society of Chemistry 2009.
- Cornella, Josep,Sanchez, Carolina,Banawa, David,Larrosa, Igor
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- Reactions of Aryl Diazonium Salts and Arylazo Alkyl Ethers. 7. Kinetic Studies of the Decomposition of Z Ethers Derived from Some Substituted 2-Nitrobenzene Diazonium Salts
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Rate constans for the decomposition of (Z)-syn ethers derived from some 4- or 5-substituted 2-nitrobenzenediazonium salts have been measured in both basic ethanol.For some compounds the rate of decomposition is independent of the base concetration while for others the rate is first order in base concetration.Solvent and substituent effects poit to the base-independent mechanism occuring on the free diazonium salt formed by ionization of the Z ether while the base-dependent mechanism occurs on the Z ether itself.Mechanisms are proposed for each of these reactions.
- Broxton, Trevor J.,McLeish, Michael J.
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- Efficient and economic halogenation of aryl amines via arenediazonium tosylate salts
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Arenediazonium tosylate salts have been successfully employed as a new and efficient reagent in halogenation reactions. A novel and economic protocol has been developed for the bromination and chlorination of various anilines using arenediazonium tosylate salts. A wide variety of reaction conditions were studied in acetonitrile at either room temperature or 60 °C in the presence or absence of catalyst with good to excellent yields. A surprising result showed the formation of acetanilides as a major product of aniline and methyl-substituted aniline halogenations in high yields.
- Lee, Young Min,Moon, Mi Eun,Vajpayee, Vaishali,Filimonov, Victor D.,Chi, Ki-Whan
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- Electrophilic Aromatic Nitration Using a Mixed Catalyst of Lithium, Molybdenum, Ytterbium on Silica Gel
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A novel mixed catalyst of LiClO4 (15% w/w), Yb(OPf)3 (15% w/w, Pf = perfluorooctanesulfonyl), MoO3 (15% w/w) on silica gel for electrophilic aromatic nitration reaction has been explored. The nitration reactions were accomplished by this mixed catalyst and nitric acid under solvent-free conditions. Moreover, the mixed catalyst can be easily recovered from the aqueous layer by heating in an oven and reused for the next nitration reaction.
- Shi, Min,Cui, Shi-Cong
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- Ipso-nitration of arylboronic acids with bismuth nitrate and perdisulfate
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An efficient and one pot synthetic method of ipso-nitration of arylboronic acids has been developed. The high efficiency, general applicability, and broader substrate scope including heterocycles and functional groups make this method advantageous. Due to its simplicity, we expect to find application of this method in synthesis.
- Manna, Srimanta,Maity, Soham,Rana, Sujoy,Agasti, Soumitra,Maiti, Debabrata
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- AI203/MeS03H (AMA) as a novel heterogeneous system for the nitration of aromatic compounds by magnesium nitrate hexahydrate
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Mg(NO3)2-6H2O was an efficient nitrating agent in the presence of a mixture of AI2O3/MeSO 3H (AMA) as a novel heterogeneous system for the nitration of aromatic compounds without use of any organic solvents and with high selectivity. The reaction proceeds at room temperature for the nitration of highly reactive aromatic compounds such as phenols and anilines.
- Hosseini-Sarvari, Mona,Tavakolian, Mina
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- Oxidation of aromatic amines into nitroarenes with m-CPBA
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A versatile and highly efficient approach for the synthesis of nitroarenes from aromatic amine using m-CPBA has been developed. This oxidation reaction was operationally straightforward and proceeded to afford products in good isolated yields.
- Liu, Jia,Li, Jue,Ren, Jiangmeng,Zeng, Bu-Bing
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- Fast and efficient nitration of salicylic acid and some other aromatic compounds over H3PO4/TiO2-ZrO2 using nitric acid
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TiO2-ZrO2 (1/1)-surf with Ti and Zr molar ratio of 1/1 was prepared with surfactant through a sol-gel method. The optimum experimental condition was investigated for nitration of salicylic acid. Then, a number of nitration reactions were carried out with a variety of aromatic compounds in the optimum condition. The 25 wt% H3PO4/TiO2-ZrO2 (1/1)-surf catalyst showed good selectivity and yield in a short time for the nitration of salicylic acid and some other aromatic compounds.
- Kalbasi, Roozbeh Javad,Massah, Ahmad Reza,Zamani, Farzad,Hamid, Javaherian Naghash
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- A convenient room temperature ipso-nitration of arylboronic acid catalysed by molecular iodine using zirconium oxynitrate as nitrating species: An experimental and theoretical investigation
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A simple and convenient protocol has been developed for ipso-nitration of arylboronic acid catalysed by molecular iodine at room temperature, using zirconium oxynitrate as the nitrating species. The protocol is applicable to electronically diverse aryl- and heteroarylboronic acid moieties under mild reaction conditions with good to excellent isolated yields. Furthermore, a theoretical investigation has been performed for the same reaction, and reaction profiles are modelled using modern density functional theory (DFT). DFT-based results support the experimentally observed results.
- Mahanta, Abhijit,Gour, Nanda Kishor,Sarma, Plaban Jyoti,Borah, Raju Kumar,Raul, Prasanta Kumar,Deka, Ramesh Chandra,Thakur, Ashim Jyoti,Bora, Utpal
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- Electrophilic aromatic nitration using perfluorinated rare earth metal salts in fluorous phase
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In this paper, we describe a practical, useful electrophilic aromatic nitration process in fluorous phase by using perfluorodecalin (C10F18, cis- and trans-mixture) as a fluorous solvent and perfluorinated rare earth metal salt [Yb(OSO2C8F17)3] as a catalyst for the electrophilic aromatic nitration.
- Shi, Min,Cui, Shi-Cong
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- An efficient and eco-friendly MoO3-SiO2 solid acid catalyst for electrophilic aromatic nitration with N2O5
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Electrophilic aromatic nitration using N2O5 as a green nitrating agent catalyzed by MoO3-SiO2 under mild conditions has been described. A series of MoO3-SiO2 catalysts with varying MoO3 loadings (5-20 mol%) were prepared by sol-gel technique and characterized using FTIR, XRD, SEM, BET and NH 3-TPD to study its surface properties. MoO3-SiO 2 shows good catalytic activity and reusability for the nitration of alkyl and halogen aromatics giving high conversions, but less efficiency for the deactivated aromatics. Reactions conducted under non-acidic conditions using N2O5 makes the process safe and environmentally friendly. Graphical Abstract: [Figure not available: see fulltext.]
- Ma, Xiaoming,Li, Bindong,Lv, Chunxu,Lu, Ming,Wu, Jian,Liang, Linjie
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- Kinetics of the oxidation of aromatic C-nitroso compounds by nitrogen dioxide
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The oxidation of nitrosobenzene by nitrogen dioxide in carbon tetrachloride has been re-examined, the rate of reaction exhibiting first-order dependence upon the concentrations of both nitrosobenzene and nitrogen dioxide, with a reactant stoichiometry of 1:1. The rate of reaction is found to be highly sensitive to the presence of trace quantities of water and intensive drying procedures for the solvent have been developed such that the reaction rate could be reduced to a constant level. For nitrosobenzene and a range of substituted nitrosobenzenes the kinetics of the oxidation reaction in carbon tetrachloride have been studied over the temperature range 291-313 K using the stopped flow technique and pseudo-first-order conditions with the nitrogen dioxide in excess. Arrhenius parameters have been obtained for 15 nitrosoarenes and the results obtained are discussed with reference to the Hammett σ constants and the electron population at the nitroso nitrogen as determined by CNDO calculations. It is concluded that the reaction occurs by a radical addition mechanism to the nitroso nitrogen atom giving an unstable aminoxyl intermediate which decomposes rapidly giving the corresponding nitrobenzene and nitric oxide.
- Gowenlock, Brian G.,Pfab, Josef,Young, Victor M.
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- Selective nitration of aromatic compounds by solid acid catalysts
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High activity and para-selectivity in the nitration of aromatic compounds is achieved by a high density of acidic sites and ready formation of the para-isomer in the pores of zeolite beta with low Si/Al ratio as revealed by molecular modeling studies.
- Choudary,Sateesh,Lakshmi Kantam,Koteswara Rao,Ram Prasad,Raghavan,Sarma
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- Regioselectivity nitration of aromatics with N2O5 in PEG-based dicationic ionic liquid
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Regioselective mononitration of simple aromatic compounds has been investigated with N2O5 as nitrating agent and a new PEG200-based dicationic acidic ionic liquid (PEG200-DAIL) as catalyst. The results of experiments show that this nitration system can significantly improve the para-selectivity of alkyl-benzenes and the ortho-selectivity of halogenated-benzenes. The PEG200-DAIL exhibits recyclable temperature-dependant phase behavior in CCl4 solvent, and it can be recycled without apparent loss of catalytic activity, and only 5% loss of weight is observed after six times recycling.
- Wang, Peng-Cheng,Lu, Ming
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- para-Selective nitration of halogenobenzenes using a nitrogen dioxide-oxygen-zeolite system
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The nitration of halogenobenzenes using zeolite Hβ or zeolite HY as a solid inorganic catalyst and a combination of liquid nitrogen dioxide and gaseous oxygen as the nitrating reagent leads to high yields and significant para-selectivities in a relatively clean process for aromatic nitration.
- Smith,Almeer,Black
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- Synthesis, structure, and synthetic potential of arenediazonium trifluoromethanesulfonates as stable and safe diazonium salts
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Aromatic diazonium salts are valuable building blocks for organic synthesis; however, in most cases, they are unstable, unsafe, poorly soluble, and/or expensive. In this paper, we have shown that a variety of stable and safe arenediazonium triflates ArN2+ TfO– can be obtained easily and in high yields by diazotization of anilines with tert-butyl nitrite in the presence of trifluoromethanesulfonic acid. Arenediazonium triflates are relatively shelf-stable in the dry state. They dissolve well in water, as well as polar and even nonpolar organic solvents. Less than 800 J/g of energy is released during the thermal decomposition of these salts, which indicates their explosion safety. Arenediazonium triflates have a high reactivity in the known reactions of diazonium chemistry, and undergo an unusual metal-free chlorodediazonization reaction with chloroform and CCl4.
- Filimonov, Victor D.,Krasnokutskaya, Elena A.,Kassanova, Assia Zh.,Fedorova, Valentina A.,Stankevich, Ksenia S.,Naumov, Nikolay G.,Bondarev, Alexander A.,Kataeva, Veronika A.
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- Phosphoric acid modified montmorillonite clay: A new heterogeneous catalyst for nitration of arenes
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The easily available montmorillonite clay is treated with phosphoric acid and 10 wt.% is found to be the optimum concentration of phosphoric acid that can be adsorbed chemically on the surface of the clay. Acidity of this phosphoric acid treated montmorillonite clay (PAM) is determined by volumetric as well as potentiometric titration and characterized. Catalytic efficacy of PAM in nitration of various aromatic compounds is reported.
- Bharadwaj, Saitanya K.,Boruah, Purna K.,Gogoi, Pradip K.
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- Iron(III)-mediated photocatalytic selective substitution of aryl bromine by chlorine with high chloride utilization efficiency
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An iron(III)-mediated photocatalytic method for the conversion of aryl, heteroaryl and polycyclic aromatic bromides to the corresponding chlorides with high selectivity has been achieved successfully. The mild reaction conditions and high chloride utilization efficiency promise a bright future for chlorination reactions. The Royal Society of Chemistry 2014.
- Wang, Ying,Li, Lina,Ji, Hongwei,Ma, Wanhong,Chen, Chuncheng,Zhao, Jincai
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- Regioselective nitration of aromatic compounds in an aqueous sodium dodecylsulfate and nitric acid medium
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An aqueous solution of sodium dodecylsulfate in the presence of dilute nitric acid at room temperature works as a mild medium for the nitration of aromatic compounds with high regioselectivity.
- Dey, Jahar,Saha, Mithu,Pal, Amarta Kumar,Ismail, Kochi
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- Kinetic and mechanistic studies of the nonchain radical nucleophilic substitution reactions
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The kinetics of the radical nucleophilic substitution reaction of p- nitrochlorobenzene with the sodium salt of the ethyl α-cyanoacetate carbanion in dimethyl sulfoxide (DMSO) solution at 335.9, 340.1, 343.9, 347.7, and 351.4 K were determined by observing the increase of the UV- visible absorbance of the product, the ethyl α-cyano-α-(p- nitrophenyl)acetate carbanion. The activation energies and entropies for the single electron transfer (k1) and for the p-nitrochlorobenzene radical anion dissociation (k2) were obtained. These results strongly support the previous conclusion that the thermal nucleophilic substitution reactions of o- and p- nitrohalobenzenes with the sodium salt of ethyl α-cyanoacetate carbanion in DMSO solution proceed exclusively via a nonchain radical mechanism (Scheme II).
- Zhang,Yang,Jia,Liu
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- Regioselective mononitration of aromatic compounds with N2O5 by acidic ionic liquids via continuous flow microreactor
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We employed N2O5 as highly active nitrating reagents and a host of acidic ionic liquid as catalysts in these reactions which were conducted in a continuous flow microreactor. When we utilized PEG400-DAIL as catalysts, the conversion of toluene was increased to 95.5 % and the yield of mononitration product (o/p ratio reached 1.10) significantly improved to 99 %, meanwhile the reaction time was drastically shortened to 1/120 of the conventional reactor. Nitration in ionic liquids was surveyed using a host of aromatic substrates with similar reactivity. The ionic liquid recycling procedures had also been devised.
- Liu, Jianhua,Li, Bindong,Wang, Huan
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- Highly efficient protocol for the aromatic compounds nitration catalyzed by magnetically recyclable core/shell nanocomposite
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An efficient protocol for the nitration of aromatic compounds in the presence of a catalytic amount of sulfuric acid-functionalized silica-based magnetic core/shell nanocomposite was reported. The designed products were obtained in high yields in relatively short reaction times at room temperature under solvent-free conditions. The nanocatalyst was simply recovered from the reaction mixture by using an external magnet and efficiently reused for several times. The characterization of particle size, morphology and elemental analysis of the nanocatalyst were provided by scanning electron microscopy, transmission electron microscopy and energy-dispersive X-ray spectroscopy analyses, respectively.
- Maleki, Ali,Aghaei, Morteza,Paydar, Reza
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- ipso-nitration of arylboronic acids with chlorotrimethylsilane-nitrate salts
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A mixture of nitrate salt and chlorotrimethylsilane is found to be an efficient regioselective nitrating agent for the ipso-nitration of arylboronic acids to produce the corresponding nitroarenes in moderate to excellent yields. High selectivity, simplicity, and convenience are the key features of the reaction.
- Surya Prakash,Panja, Chiradeep,Mathew, Thomas,Surampudi, Vijayalakshmi,Petasis, Nicos A.,Olah, George A.
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- Nitration of aromatic compounds with nitric acid catalyzed by ionic liquids
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Nitration of simple aromatic compounds with 62% nitric acid is successfully carried out under solvent-free condition in a biphasic mode in the presence of the Bronsted acidic ionic liquids; the only by-product is water and ionic liquids are capable of being reused without any separation.
- Qiao, Kun,Yokoyama, Chiaki
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- Nitration of aromatics with dinitrogen pentoxide in a liquefied 1,1,1,2-tetrafluoroethane medium
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Regardless of the sustainable development path, today, there are highly demanded chemical productions still operating that bear environmental and technological risks inherited from the previous century. The fabrication of nitro compounds, and nitroarenes in particular, is traditionally associated with acidic wastes formed in nitration reactions exploiting mixed acids. However, nitroarenes are indispensable for industrial and military applications. We faced the challenge and developed a greener, safer, and yet effective method for the production of nitroaromatics. The proposed approach comprises the application of an eco-friendly nitrating agent, namely dinitrogen pentoxide (DNP), in the medium of liquefied 1,1,1,2-tetrafluoroethane (TFE) - one of the most non-hazardous Freons. Importantly, the used TFE is not emitted into the atmosphere but is effortlessly recondensed and returned into the process. DNP is obtainedviathe oxidation of dinitrogen tetroxide with ozone. The elaborated method is characterized by high yields of the targeted nitro arenes, mild reaction conditions, and minimal amount of easy-to-utilize wastes.
- Fauziev, Ruslan V.,Kharchenko, Alexandr K.,Kuchurov, Ilya V.,Zharkov, Mikhail N.,Zlotin, Sergei G.
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- One-Electron Reduction of Nitrobenzenes by OH and H Radical Adducts to 6-Methyluracil and 6-Methylisocytosine via Electron Transfer and Addition/Elimination. Effect of Substituents on Rates and Activation Parameters for Formation and Heterolysis of Nitroxyl-Type Thetrahedral Intermediate
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The radicals formed by OH radical addition to C-5 of 6-methyluracil or of 6-methylisocytosine, i.e., 5-hydroxy-5,6-dihydro-6-methyluracil-6-yl or 5-hydroxy-5,6-dihydro-6-methylisocytosin-6-yl, or that produced by H addition to C-5 of 6-methyluracil (or by H abstraction from C-6 of 5,6-dihydro-6-methyluracil), i.e., 5,6-dihydro-6-methyluracil-6-yl, reacts in aqueous solution with para-substituted nitrobenzenes to give both nitrobenzene radical anions and nitroxyl-type radicals with rate constants that vary from ca. 7E7 to (2-5)E9 M-1s-1, depending on the pyrimidine radical and on the nitrobenzene.The nitroxyl radicals undergo a spontaneous unimolecular heterolysis to yield (additional) nitrobenzene radical anion and oxidized pyrimidine with rate constants of 1E3 to 5E5 s-1 depending on the structure of the pyrimidine and of the nitrobenzene.This reaction is characterized by activation enthalpies of 30-40 kJ mol-1 and by activation entropies of -7 to -89 J mol-1 K-1 (entropy control).The addition/elimination sequence constitutes a case of inner-sphere electron transfer.The rate constants for the heterolysis reaction are a measure of the reducing power of 5,6-dihydro-6-methylpyrimidin-6-yl radicals.On this basis, the cytosine radicals are better reductants than the corresponding uracil radicals, and the radicals derived by hydrogen atom addition to pyrimidines are stronger reductants than those formed by OH radical addition.
- Jagannadham, V.,Steenken, S.
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- Electrophilic Aromatic Nitration in the Gas Phase
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Aromatic nitration by MeO+(H)NO2, in essence nitronium ion solvated by one methanol molecule, has been studied in the gas phase by using an integrated approach, based on the coordinate application of ICR, Cl, and CID mass spetrometric methods with a highly complementary radiolytic technique.The latter can be used in gases at atmospheric pressure and allows direct evaluation of key mechanistic features, in particular of substrate and positional selectivity.The results resolve early discrepancies between gas-phase and liquid-phase studies, characterizing the reaction as a typical, well-behaved electrophilic substitution of moderate selectivity.The date from the gas-phase nitration of ten monosubstituted benzenes fit a Hammett's type linear plot, characterized by a ρ value of -3.87.The correlation does not extend to highly activated substrates, such as anisole and mesitylene, since the nitration rate tends to a limiting value that cannot be increased by further enhancing the activation of the substrate, exactly as in "encounter-rate" nitrations occurring in solution.The mechanism and the energetics of the gas-phase nitration have been investigated, and the relative stability of the charged intermediates involved, in particular of the isomeric protonated nitrobenzenes, has been estimated by theoretical approaches at two different levels, using STO-3G minimal basis and 4-31G split-valence basis sets.
- Attina, Marina,Cacace, Fulvio,Yanez, Manuel
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- Nitrations and Oxidations with Inorganic Nitrate Salts in Trifluoroacetic Anhydride
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Metal nitrates in trifluoroacetic anhydride nitrate many aromatic compounds in high yields at room temperature, including polymers with aromatic groups.However, this system oxidizes phenols to quinoid products.
- Crivello, J.V.
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- PALLADIUM CATALYZED DECARBONYLATION OF AROMATIC ACYL CHLORIDES
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A variety of palladium catalysts have been found to effectively promote the decarbonylation of aromatic acyl chlorides at elevated temperatures.
- Verbicky, John W.,Dellacoletta, Brent A.,Williams, Louella
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- Oxidation of Primary Amines by Dimethyldioxirane
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Dimethyldioxirane oxidizes primary amines rapidly, and generally in high yield, to the corresponding nitro compounds.The method can also be used to syntesize polynitro compounds.
- Murray, Robert W.,Rajadhyaksha, Shirish N.,Mohan, Lily
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- Aromatic nitration with bismuth nitrate in ionic liquids and in molecular solvents: A comparative study of Bi(NO3)3·5H 2O/[bmim][PF6] and Bi(NO3)3· 5H2O/1,2-DCE systems
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A suspension of bismuth nitrate pentahydrate (BN) in [bmim][PF6] or [bmim][BF4] imidazolium ionic liquid (IL) is an effective reagent for ring nitration of activated aromatics under mild conditions without the need for external promoters. Nitration can also be effected in 1,2-DCE, MeCN, or MeNO2 without additives. Nitration of activated arenes (anisole, toluene, ethylbenzene, cumene, p-xylene, mesitylene, durene, and 1,3-dimethoxybenzene) is considerably faster (time to completion) in BN/[bmim][PF6] relative to BN/1,2-DCE and there are also differences in isomer distributions (for anisole, toluene, and ethylbenzene). With introduction of strongly deactivating substituents (-CHO; -MeCO; -NO 2) the BN/IL system is no longer active but reactions still proceed with BN/1,2-DCE in reasonable yields. The ready availability and low cost of BN, simple operation, and absence of promoters, coupled to recycling and reuse of the IL, provide an attractive alternative to classical nitration methods for activated arenes. Switching from Bi(NO3)3·5H 2O/[bmim][PF6] to Bi(NO3)3· 5H2O/1,2-DCE increases the scope of the substrates that can be nitrated.
- Jacoway, Jonathan,Kumar, G. G. K. S. Narayana,Laali, Kenneth K.
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- Catalyst free, base free microwave irradiated synthesis of aryl nitrites from potassium aryltrifluoroborates and bismuth nitrate
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A mixture of bismuth nitrate pentahydrate and potassium aryltrifluoroborate in toluene under microwave heating at 120 C for 20 min provides an interesting and mild reaction protocol for the synthesis of aryl nitrite. The conversion to aryl nitrites from aryltrifluoroborates without transition metal catalyst and base in high yields is remarkable.
- Al-Masum, Mohammad,Welch, Rebecca L.
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- Relative Electron Affinities of Substituted Nitrobenzenes in the Gas Phase
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Using pulsed ion cyclotron resonance mass spectrometry, we have determined the relative electron affinities of 12 substituted nitrobenzenes in the gas phase by measuring equilibrium constants for electron transfer reactions of the type C6H5NO2- + X-C6H4NO2 = X-C6H4NO2- + C6H5NO2, where X is a substituent group.An excellent correlation is found between the relative electron affinities of the substituted nitrobenzenes and the relative gas-phase acidities of substituted anilines and phenols.
- Fukuda, Elaine K.,McIver, Robert T.
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- Aromatic nitrations in ionic liquids: The importance of cation choice
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Aromatic substrates can be nitrated in high yields and with efficient use of the nitrating agent in ionic liquids, although a suitably inert ionic liquid cation must be used.
- Lancaster, N. Llewellyn,Llopis-Mestre, Veronica
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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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- Synthesis method of metolachlor intermediate
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The synthesis method comprises the following steps: S1) nitration reaction of chlorobenzene in a nitration reagent to obtain a mixture of o-chloronitrobenzene and p-chloronitrobenzene without separation. S2) The mixture of o-chloronitrobenzene and p-chloronitrobenzene is subjected to catalytic hydrogenation reaction to obtain the mixture of o-chloroaniline and p-chloroaniline, and the product does not need to be separated. S3) The mixture of o-chloroaniline and chloroaniline is subjected to diazotization reaction to obtain the mixture of o-chlorophenylhydrazine and p-chlorophenylhydrazine, and the product does not need to be separated. S4) The mixture of o-chlorophenylhydrazine and p-chlorophenylhydrazine and aldehyde are subjected to a condensation reaction to obtain a triazole ring mixture of Formulae I through a and I through b. S5) The triazole ring mixture is subjected to chlorination reaction to obtain the metolachlor intermediate shown in the formula I. 2, 4 - Dichloroaniline is used as a raw material, the production cost of the metolachlor is reduced, and the supply limitation of the raw material is avoided.
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Paragraph 0078-0084; 0097-0103
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- Selective Mild Oxidation of Anilines into Nitroarenes by Catalytic Activation of Mesoporous Frameworks Linked with Gold-Loaded Mn3O4 Nanoparticles
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This work reports the synthesis and catalytic application of mesoporous Au-loaded Mn3O4 nanoparticle assemblies (MNAs) with different Au contents, i. e., 0.2, 0.5 and 1 wt %, towards the selective oxidation of anilines into the corresponding nitroarenes. Among common oxidants, as well as several supported gold nanoparticle platforms, Au/Mn3O4 MNAs containing 0.5 wt % Au with an average particle size of 3–4 nm show the best catalytic performance in the presence of tert-butyl hydroperoxide (TBHP) as a mild oxidant. In all cases, the corresponding nitroarenes were isolated in high to excellent yields (85–97 %) and selectivity (>98 %) from acetonitrile or greener solvents, such as ethyl acetate, after simple flash chromatography purification. The 0.5 % Au/Mn3O4 catalyst can be isolated and reused four times without a significant loss of its activity and can be applied successfully to a lab-scale reaction of p-toluidine (1 mmol) leading to the p-nitrotulene in 83 % yield. The presence of AuNPs on the Mn3O4 surface enhances the catalytic activity for the formation of the desired nitroarene. A reasonable mechanism was proposed including the plausible formation of two intermediates, the corresponding N-aryl hydroxylamine and the nitrosoarene.
- Armatas, Gerasimos S.,Daikopoulou, Vassiliki,Koutsouroubi, Eirini D.,Lykakis, Ioannis N.,Skliri, Euaggelia
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- The polyhedral nature of selenium-catalysed reactions: Se(iv) species instead of Se(vi) species make the difference in the on water selenium-mediated oxidation of arylamines
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Selenium-catalysed oxidations are highly sought after in organic synthesis and biology. Herein, we report our studies on the on water selenium mediated oxidation of anilines. In the presence of diphenyl diselenide or benzeneseleninic acid, anilines react with hydrogen peroxide, providing direct and selective access to nitroarenes. On the other hand, the use of selenium dioxide or sodium selenite leads to azoxyarenes. Careful mechanistic analysis and 77Se NMR studies revealed that only Se(iv) species, such as benzeneperoxyseleninic acid, are the active oxidants involved in the catalytic cycle operating in water and leading to nitroarenes. While other selenium-catalysed oxidations occurring in organic solvents have been recently demonstrated to proceed through Se(vi) key intermediates, the on water oxidation of anilines to nitroarenes does not. These findings shed new light on the multifaceted nature of organoselenium-catalysed transformations and open new directions to exploit selenium-based catalysis.
- Capperucci, Antonella,Dalia, Camilla,Tanini, Damiano
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supporting information
p. 5680 - 5686
(2021/08/16)
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- The graphite-catalyzed: ipso -functionalization of arylboronic acids in an aqueous medium: metal-free access to phenols, anilines, nitroarenes, and haloarenes
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An efficient, metal-free, and sustainable strategy has been described for the ipso-functionalization of phenylboronic acids using air as an oxidant in an aqueous medium. A range of carbon materials has been tested as carbocatalysts. To our surprise, graphite was found to be the best catalyst in terms of the turnover frequency. A broad range of valuable substituted aromatic compounds, i.e., phenols, anilines, nitroarenes, and haloarenes, has been prepared via the functionalization of the C-B bond into C-N, C-O, and many other C-X bonds. The vital role of the aromatic π-conjugation system of graphite in this protocol has been established and was observed via numerous analytic techniques. The heterogeneous nature of graphite facilitates the high recyclability of the carbocatalyst. This effective and easy system provides a multipurpose approach for the production of valuable substituted aromatic compounds without using any metals, ligands, bases, or harsh oxidants.
- Badgoti, Ranveer Singh,Dandia, Anshu,Parewa, Vijay,Rathore, Kuldeep S.,Saini, Pratibha,Sharma, Ruchi
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p. 18040 - 18049
(2021/05/29)
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- Low-temperature and highly efficient liquid-phase catalytic nitration of chlorobenzene with NO2: Remarkably improving the para-selectivity in O2-Ac2O-Hβ composite system
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In this work, we developed a low-temperature and efficient approach for the highly selective preparation of valuable p-nitrochlorobenzene from the liquid-phase catalytic nitration of chlorobenzene with NO2 in O2-Ac2O-Hβ composite system. The results demonstrated that the introduction of molecular oxygen remarkably enhanced the chlorobenzene conversion and the cooperation catalysis of Hβ zeolite and Ac2O envidently improved the selectivity to para-nitro product. Under the optimized reaction conditions, 93.6 % of the selectivity to p-nitrochlorobenzene with 84.0 % of chlorobenzene conversion was obtained, and the ratio of p-nitrochlorobenzene to o-nitrochlorobenzene could reach up to 20.3. Furthermore, the selectivity distribution of nitration products was reasonably explained by the density functional theory (DFT) calculation. Finally, the possible nitration reaction pathway of chlorobenzene with NO2 was suggested in O2-Ac2O-Hβ composite catalytic system. The present work affords a new and mild nitration approach for highly selective preparation of valuable para-nitro products, and has potential industrial application prospects.
- Deng, Renjie,Liu, Pingle,Luo, He'an,Ni, Wenjin,You, Kuiyi,Zhao, Fangfang
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- Continuous production process of p-nitrophenol
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The invention relates to a continuous production process of p-nitrophenol. The continuous production process is based on a set of continuous production system, all devices in the continuous productionsystem cooperate with one another, continuous work is a
- -
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Paragraph 0029-0039; 0045-0055; 0061-0072
(2020/11/01)
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- Two-Phase Electrochemical Generation of Aryldiazonium Salts: Application in Electrogenerated Copper-Catalyzed Sandmeyer Reactions
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The electrochemical generation of aryldiazonium salts from nitroarenes in a two-phase system (ethyl acetate/water) was reported for the first time. Some compounds including azo, azosulfone, and arylazides were prepared in good yields with good purity. Cathodically generated aryldiazoniums and anodically produced copper(Ι) ions were used to perform Sandmeyer reactions. To improve the method, an H-type self-driving cell equipped with a Zn rod as an anode was introduced and used for two-phase aryldiazonium production.
- Goljani, Hamed,Tavakkoli, Zahra,Sadatnabi, Ali,Nematollahi, Davood
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supporting information
p. 5920 - 5924
(2020/08/12)
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- Synthesis of thioethers, arenes and arylated benzoxazoles by transformation of the C(aryl)-C bond of aryl alcohols
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Transformation of aryl alcohols into high-value functionalized aromatic compounds by selective cleavage and functionalization of the C(aryl)-C(OH) bond is of crucial importance, but very challenging by far. Herein, for the first time, we report a novel and versatile strategy for activation and functionalization of C(aryl)-C(OH) bonds by the cooperation of oxygenation and decarboxylative functionalization. A diverse range of aryl alcohol substrates were employed as arylation reagents via the cleavage of C(aryl)-C(OH) bonds and effectively converted into corresponding thioether, arene, and arylated benzoxazole products in excellent yields, in a Cu based catalytic system using O2 as the oxidant. This study offers a new way for aryl alcohol conversion and potentially offers a new opportunity to produce high-value functionalized aromatics from renewable feedstocks such as lignin which features abundant C(aryl)-C(OH) bonds in its linkages.
- Chen, Bingfeng,Han, Buxing,Liu, Mingyang,Meng, Qinglei,Song, Jinliang,Zhang, Pei,Zhang, Zhanrong
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p. 7634 - 7640
(2020/08/14)
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- Dehydroxyalkylative halogenation of C(aryl)-C bonds of aryl alcohols
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We herein report Cu mediated side-directed dehydroxyalkylative halogenation of aryl alcohols. C(aryl)-C bonds of aryl alcohols were effectively cleaved, affording the corresponding aryl chlorides, bromides and iodides in excellent yields. Aryl alcohols could serve as both aromatic electrophilic and radical synthetic equivalents during the reaction.
- Liu, Mingyang,Zhang, Zhanrong,Liu, Huizhen,Wu, Tianbin,Han, Buxing
-
supporting information
p. 7120 - 7123
(2020/07/14)
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- NITRATION
-
The present invention relates to a process for preparing a nitrated compound, comprising the step of reacting a compound (A) comprising at least one substituted or unsubstituted aromatic or heteroaromatic ring, wherein said heteroaromatic ring comprises at least one heteroatom selected from the group consisting of oxygen, sulfur, phosphor, selenium and nitrogen, with a compound of formula (I) wherein Y is selected from the group consisting of hydrogen and nitro.
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Page/Page column 36; 41; 46; 64; 37; 42; 48; 67
(2020/05/28)
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- N-Nitroheterocycles: Bench-Stable Organic Reagents for Catalytic Ipso-Nitration of Aryl- And Heteroarylboronic Acids
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Photocatalytic and metal-free protocols to access various aromatic and heteroaromatic nitro compounds through ipso-nitration of readily available boronic acid derivatives were developed using non-metal-based, bench-stable, and recyclable nitrating reagents. These methods are operationally simple, mild, regioselective, and possess excellent functional group compatibility, delivering desired products in up to 99% yield.
- Budinská, Alena,Katayev, Dmitry,Passera, Alessandro,Zhang, Kun
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supporting information
(2020/03/30)
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- Synthesis method of aromatic nitro-compound
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The invention discloses a synthesis method of an aromatic nitro-compound. The synthesis method is characterized in that the aromatic nitro-compound is obtained by taking an aromatic amino-compound asa raw material and performing an oxidation reaction on the aromatic amino-compound and peroxytrifluoroacetic acid. The target aromatic nitro-compound is obtained by taking the aromatic amino-compoundas the raw material and performing the oxidation reaction on the aromatic amino-compound and peroxytrifluoroacetic acid; the synthesis method is high in yield, wide in application range, simple in operation and little in environmental pollution, therefore, the synthesis method is a good and ideal method for preparing the aromatic nitro-compound.
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-
Paragraph 0020; 0024
(2019/10/29)
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- Rhodium-Catalyzed Reaction of Azobenzenes and Nitrosoarenes toward Phenazines
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A rhodium-catalyzed annulative reaction between azobenzenes and nitrosoarenes has been developed, leading to a series of phenazines in moderate to good yields. This procedure proceeds with sequential chelation-assisted addition of aryl C-H to nitrosoarenes and ring closure by electrophilic attack of azo group to aryl. During this transformation, the azo group served as not only a traceless directing group but also a building block in the final products.
- Xiao, Yan,Wu, Xiaopeng,Wang, Hepan,Sun, Song,Yu, Jin-Tao,Cheng, Jiang
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supporting information
p. 2565 - 2568
(2019/04/30)
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- Method for preparing nitro compound by using graphene to catalyze carbon dioxide
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The invention discloses a method for preparing a nitro compound by using graphene to catalyze carbon dioxide. A graphene material is applied to catalysis of a reaction of carbon dioxide and a nitrification substrate such as an aromatic compound to prepare the nitro compound. The method is used for replacing a traditional nitric acid/sulfur acid method to prepare the nitro compound, so that the atom utilization rate of the reaction is increased, the energy is saved, and the emission is reduced; and the method has the characteristic of atom economy during industrial preparation of the nitro compound.
- -
-
Paragraph 0033-0034
(2018/06/16)
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- Method for preparing nitro compound by using graphene to catalyze nitric oxide
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The invention discloses a method for preparing a nitro compound by using graphene to catalyze nitric oxide. A graphene oxide carbon material is used for catalysis of a reaction of nitric oxide and a nitrification substrate such as an aromatic compound to prepare the nitro compound. The method is used for replacing a traditional nitric acid/sulfur acid method to prepare the nitro compound, so thatthe atom utilization rate of the reaction is increased, the energy is saved, and the emission is reduced; and the method has the characteristic of atom economy during industrial preparation of the nitro compound.
- -
-
Paragraph 0037; 0038
(2018/06/16)
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- Silica-supported perchloric acid and potassium bisulfate as reusable green catalysts for nitration of aromatics under solvent-free microwave conditions
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Silica-supported perchloric acid and bisulfate (SiO2/HClO4 and SiO2/KHSO4) have been developed as reusable green catalysts for nitration of aromatic compounds using NaNO2 in acetonitrile medium under conventional and solvent-free microwave conditions. The reaction times under microwave irradiation are significantly shorter than conventional method even though the yields obtained in microwave-assisted reactions are comparable with those obtained under reflux conditions.
- Kumar, M. Satish,Sriram, Y. Hemanth,Venkateswarlu,Rajanna,Sudhakar, M. Sai,Venkanna, Purugula,Saiprakash
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supporting information
p. 59 - 67
(2017/12/26)
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- HNO3/HFIP: A Nitrating System for Arenes with Direct Observation of π-Complex Intermediates
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This report describes an efficient nitrating system for the nitration of arenes at room temperature by using an equivalent of nitric acid in HFIP (1,1,1,3,3,3-hexafluoroisopropanol). The π-complex intermediate of an arene with a nitronium ion stabilized by HFIP can be directly observed by UV-vis spectra and is supported by theoretical calculations.
- Lu, Le,Liu, Huixin,Hua, Ruimao
-
supporting information
p. 3197 - 3201
(2018/06/11)
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- Mechanical force under the action of the nitration of aromatic compounds of nitrate method (by machine translation)
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The invention discloses a mechanical force under the action of the nitration of aromatic compounds of nitrate method. The invention provides a method for preparing aromatic nitro compounds, comprising the following steps: under the action of mechanical force, aromatic compound with a metal nitrate or its hydrate by the nitration reaction, to obtain the aromatic nitro compound; the mechanical fastener is machinery offers can cause material physical and/or chemical nature of the change of the external force. The mechanical force can be compression, shear, impact, friction, tensile, bending and vibration of any kind. The invention has the following advantages: without the use of any solvent, thereby avoiding the waste liquid produced; and without the use of the acidic substance, the reaction is complete after treatment is simple, without any damage to the apparatus; a very high conversion and selectivity, can be applied to the nitration of conventional aromatic compound. (by machine translation)
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-
Paragraph 0050; 0051
(2018/09/11)
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- Method of manufacturing para-phenylenediamine
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The present invention relates to a method for manufacturing para-phenylenediamine, comprising the steps of: manufacturing para-nitrochlorobenzene by nitrifying chlorobenzene using nitric acid and sulfuric acid; manufacturing para-nitroaniline by aminating the manufactured para-nitrochlorobenzene; and reducing the manufactured para-nitroaniline. The present invention minimizes the pollution of a precious metal catalyst used in the reduction of para-nitroaniline because neutralizing and washing processes before the amination of para-nitrochlorobenzene and/or neutralizing and washing processes before the reduction of para-nitroaniline are conducted so that the content of sulfur ions remaining in the para-nitroaniline can be less than or equal to 1,000 ppm, thereby keeping reaction conditions and production yield unchanged even during the reuse of the precious metal catalyst. Therefore, the present invention can reduce production costs owing to the reuse of the precious metal.
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Page/Page column 5; 6
(2019/01/11)
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- Oxidation of Aniline to Nitrobenzene Catalysed by 1-Butyl-3-methyl imidazolium phosphotungstate Hybrid Material Using m-chloroperbenzoic Acid as an Oxidant
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Abstract: Keggin ion based hybrid materials, [BmIm]3[PW12O40], [TBA]3PW12O40 and [BuPy]3PW12O40, were prepared by proton exchange with organic cations, 1-butyl-3-methyl imidazolium ion, tetrabutylammonium ion and butylpyridinium ion, respectively. The formation of hybrid materials was confirmed by FTIR, PXRD, SEM, TG-DTA, DSC analysis. These hybrid compounds are active for oxidation of aniline using m-chloroperbenzoic acid as an oxidant. Among the three hybrid compounds, 1-butyl-3-methyl imidazolium phosphotungstate was found to be the best and efficient catalyst for selective aniline oxidation to nitrobenzene. It is a recoverable and reusable catalytic system. The redox property of the phosphotungstate cluster in the hybrid material is involved in the catalytic activity. Graphical Abstract: [Figure not available: see fulltext.].
- Meenakshi,Shakeela,Kutti Rani,Ranga Rao
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p. 246 - 257
(2017/10/23)
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- Magnetically recyclable Pd/Fe3O4/g-C3N4 as efficient catalyst for the reduction of nitrophenol and suzuki-miyaura reaction at room temperature
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Herein, we present the design and synthesis of a novel magnetic stable and recyclable catalyst Pd/Fe3O4/g-C3N4 with approachable active palladium nanoparticles (Pd NPs) based on the platelet-like graphitic carbon nitrides (g-C3N4). The Pd NPs, g-C3N4 and magnetic particles (Fe3O4) are tightly connected through non-covalent interactions owing to the layered structure of g-C3N4 with abundant nitrogen atoms, facilitating the stability of Pd/Fe3O4/g-C3N4 and activating the Pd NPs at the same time. The Pd/Fe3O4/g-C3N4 catalyst with a narrow particle size distribution (2.55 nm) of Pd NPs displayed the maintenance of the planar structure of g-C3N4. The activity parameter of the catalyst turned out to be excellent (12.4 s11￠mM11) by fitting the curves derived from the reduction of nitrophenol. Meanwhile, the Suzuki-Miyaura coupling reaction at room temperature processed smoothly with the Pd/Fe3O4/g-C3N4 catalyst. It is meaningful to stress that 2-bromobenzonitrile and p-tolylboronic acid could afford the medical intermediate sartanbiphenyl at total conversion without side reactions in 25 min. Furthermore, the nanocatalyst owes the properties of easy recycling using a powerful magnet as well as high turnover frequency (at least 5 runs) with retention of high catalytic activity.
- Yang, Yingwei,Tang, Ruiren
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supporting information
p. 544 - 547
(2018/04/09)
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- Synthesis of nitroolefins and nitroarenes under mild conditions
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1,3-Disulfonic acid imidazolium nitrate {[Dsim]NO3} was prepared and characterized as a new ionic liquid and nitrating agent for the ipso-nitration of various arylboronic acids and nitro-Hunsdiecker reaction of different α,β-unsaturated acids and benzoic acid derivatives, by in situ generation of NO2 to give various nitroarenes and nitroolefins without using any cocatalysts and solvents under mild conditions.
- Zarei, Mahmoud,Noroozizadeh, Ehsan,Moosavi-Zare, Ahmad R.,Zolfigol, Mohammad A.
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p. 3645 - 3650
(2018/04/14)
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- Ipso-nitration of arylboronic acids with copper nitrate and trifluoroace-tic acid
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An efficient and novel nitrating reagent has been developed for ipso-nitration of arylboronic acids. By using inexpensive and commercially available Cu(NO3)2/CF3COOH as nitrating reagent, various nitroarenes are produced in moderate to excellent yields (51-96%). Advantages of this procedure are the operational simplicity and no need of extra catalyst.
- Wang, Zhu-Qing,Guo, Meng-Ping,Wen, Yong-Ju,Shen, Xiu-Li,Lv, Mei-Yun,Zhou, Xiu-Ling
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p. 891 - 894
(2018/11/06)
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- NH4I/tert-butyl hydroperoxide-promoted oxidative C–N cleavage of tertiary amines leading to nitroaromatic compounds
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A NH4I/tert-butyl hydroperoxide-promoted oxidation of tertiary N-aryl-N,N-dialkylamines in DMSO has been developed to access nitroaromatic compounds. This methodology involves sequential N-dealkylation reactions in one-pot and a radical pathway is proposed.
- Shao, Ying,Zheng, Hao,Wu, Zhuhong,Huang, Lei,Tong, Jingjing,Wu, Ming,Sun, Xiaoqiang
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p. 504 - 508
(2017/10/03)
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- Pd-Catalyzed Decarbonylative Cross-Couplings of Aroyl Chlorides
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This report describes a method for Pd-catalyzed decarbonylative cross-coupling that enables the conversion of carboxylic acid derivatives to biaryls, aryl amines, aryl ethers, aryl sulfides, aryl boronate esters, and trifluoromethylated arenes. The success of this transformation leverages the Pd0/Brettphos-catalyzed decarbonylative chlorination of aroyl chlorides, which can then participate in diverse cross-coupling reactions in situ using the same Pd catalyst.
- Malapit, Christian A.,Ichiishi, Naoko,Sanford, Melanie S.
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supporting information
p. 4142 - 4145
(2017/08/15)
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- Synthetic method of aryl halide taking aryl carboxylic acid as raw material
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A synthetic method of an aryl halide taking aryl carboxylic acid as a raw material is characterized in that a corresponding aryl halide is formed by carrying out substitution reaction on an aryl carboxylic acid compound and haloid salt MX in an organic solvent under the condition that oxygen, a silver catalyst, a copper additive and a bidentate nitrogen ligand exist, wherein M in MX represents alkali metal or alkaline earth metal, and X represents F, Cl, Br or I. Compared with a conventional aryl halide synthetic method, the synthetic method disclosed by the invention has the obvious advantages that reaction raw materials (comprising aryl carboxylic acid and MX) are cheap and easy to obtain, the using amount of a metal catalyst is small, pollution to the environment when the oxygen is used as an oxidant is the smallest, good tolerance to various functional groups on an aromatic ring is obtained, the yield is high, and the like. The synthetic method disclosed by the invention can be widely applied to synthesis in the fields of medicine, materials, natural products and the like in industry and academia.
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Paragraph 0058
(2018/01/03)
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- Convenient, metal-free ipso-nitration of arylboronic acids using nitric acid and trifluoroacetic acid
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A feasible protocol for the direct ipso-nitration of arylboronic acids using trifluoroacetic acid and nitric acid as nitration reagent has been developed. Various aromatic nitro compounds are produced in moderate to good yields under the metal-free conditions. The method is operationally simple and regioselective, and might have potential application in industry.
- Shen, Guodong,Zhao, Lingyu,Liu, Wanxing,Huang, Xianqiang,Song, Huina,Zhang, Tongxin
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supporting information
p. 10 - 14
(2016/12/30)
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- Efficient transposition of the sandmeyer reaction from batch to continuous process
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The transposition of Sandmeyer chlorination from a batch to a safe continuous-flow process was investigated. Our initial approach was to develop a cascade method using flow chemistry which involved the generation of a diazonium salt and its quenching with copper chloride. To achieve this safe continuous process diazotation, a chemometric approach (Simplex method) was used and extrapolated to establish a fully continuous-flow method. The reaction scope was also examined via the synthesis of several (het)aryl chlorides. Validation and scale-up of the process were also performed. A higher productivity was obtained with increased safety.
- D'Attoma, Joseph,Camara, Titi,Brun, Pierre Louis,Robin, Yves,Bostyn, Stéphane,Buron, Frédéric,Routier, Sylvain
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- One-Pot C?H Functionalization of Arenes by Diaryliodonium Salts
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A transition-metal-free, mild, and highly regioselective synthesis of nitroarenes from arenes has been developed. The products are obtained in a sequential one-pot reaction by nitration of iodine(III) reagents with two carbon ligands, which are formed in situ from iodine(I). This novel concept has been extended to formation of aryl azides, and constitutes an important step towards catalytic reactions with these hypervalent iodine reagents. An efficient nitration of isolated diaryliodonium salts has also been developed, and the mechanism is proposed to proceed by a [2,2] ligand coupling pathway.
- Reitti, Marcus,Villo, Piret,Olofsson, Berit
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supporting information
p. 8928 - 8932
(2016/07/26)
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- PhPOCl2as a potent catalyst for chlorination reaction of phenols with PCl5
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Phenols are easily converted to the corresponding aryl chlorides by using phosphorus pentachloride (PCl5) and a catalytic amount of phenylphosphonic dichloride (PhPOCl2), which is a new efficient method for synthesis of aryl chloride in good yields.
- Wu, Jiang,Zhou, Junpeng,Shi, Yalei,Zhu, Jintao
-
supporting information
p. 1619 - 1624
(2016/10/09)
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- NITRATION OF AROMATIC COMPOUNDS
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The present invention provides a process for nitrating aromatic compounds without the need for a solid catalyst and/or any organic solvents and/or any other additives. A typical process includes combining or admixing a nitric acid and an anhydride compound under conditions sufficient to produce a reactive intermediate. The aromatic compound to be nitrated is then added to this reactive intermediate to produce a nitroaromatic compound. The nitroaromatic compound can be substituted with one or more, typically, one to three, and often one or two nitrate (-NO2) groups.
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-
Paragraph 0051
(2016/08/17)
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- Transition-metal-free synthesis of thiocyanato- or nitro-arenes through diaryliodonium salts
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A transition-metal-free approach to facile synthesis of thiocyanato- and nitro-arenes was developed from KSCN (potassiumthiocyanate) or NaNO2with diaryliodonium salts in good yields under mild conditions. The reaction was compatible with a variety of sensitive functional substituents such as halides and nitro and ester groups. The usefulness of arylation products has been realized. (Formula Present).
- Li, Xiao-Hua,Li, Liang-Gui,Mo, Xue-Ling,Mo, Dong-Liang
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p. 963 - 970
(2016/07/07)
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- A simple protocol for Cu-catalyzed protodecarboxylation of (hetero)aromatic carboxylic acids
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A simple and practical protodecarboxylation of o-nitrobenzoic acids as well as heteroaromatic carboxylic acids with various substituents via using CuI/Et3N has been established. This transformation provides a viable and low-cost approach to generating previously unavailable substituted arenes from readily accessible aryl carboxylic acids as the starting materials.
- Li, Zhaojie,Fu, Zhengjiang,Zhang, Haixia,Long, Jiao,Song, Yuanyuan,Cai, Hu
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supporting information
p. 3014 - 3018
(2016/05/09)
-
- Ultrasonically Assisted Rate Enhancements in Trichloroisocyanuric Acid/DMF/NaNO2 Triggered Nitration of Aromatic Compounds and Decarboxylative Nitration of α,β-Unsaturated Acids
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An efficient and safe method for nitration of aromatic compounds and decarboxylative nitration of α,β-unsaturated acids was developed using trichloroisocyanuric acid (TCICA)/dimethylformamide (DMF) in the presence of NaNO2. The reaction times of conventional protocol reduced from 8-10 h to 1.0-1.5 h (60-90 min) under sonication, even though the yields are comparable under both the conditions.
- Kumar, Mukka Satish,Rajanna, Kamatala Chinna,Venkateswarlu, Marri,Venkanna, Purugula,Saiprakash, Pondichery Kuppuswamy
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p. 2251 - 2258
(2015/09/22)
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- Steric-Hindrance-Induced Regio- and Chemoselective Oxidation of Aromatic Amines
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Unusual regio- and chemoselective oxidation of aromatic amines hindered with ortho substituents (except -NH2, -NHCH3, and -OH) to the corresponding nitro compounds is described by use of nonanebis(peroxoic acid). The mechanistic investigation for selective oxidation of amines ortho-substituted with -NH2 or -OH showed the involvement of H-bonding between the ortho hydrogen of the adjacent -XH group (where X = NH, NR, or O) and an oxygen atom from the diperoxy acid. Various mono- and diamines are oxidized into corresponding mononitro derivatives in high yield and purity without employing any protection strategies. The protocol was also found to successful on the gram scale.
- Patil, Vilas Venunath,Shankarling, Ganapati Subray
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p. 7876 - 7883
(2015/09/01)
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- The ortho-substituent effect on the Ag-Catalysed decarboxylation of benzoic acids
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A combined experimental and computational investigation on the Ag-catalysed decarboxylation of benzoic acids is reported herein. The present study demonstrates that a substituent at the ortho position exerts dual effects in the decarboxylation event. On one hand, ortho-substituted benzoic acids are inherently destabilised starting materials compared to their meta- And para-substituted counterparts. On the other hand, the presence of an ortho-electron-withdrawing group results in an additional stabilisation of the transition state. The combination of both effects results in an overall reduction of the activation energy barrier associated with the decarboxylation event. Furthermore, the Fujita- Nishioka linear free energy relationship model indicates that steric bulk of the substituent can also exert a negative effect by destabilising the transition state of decarboxylation.
- Grainger, Rachel,Cornella, Josep,Blakemore, David C.,Larrosa, Igor,Campanera, Josep M.
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supporting information
p. 16680 - 16687
(2015/03/05)
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- Eco-friendly nitration of benzenes over zeolite-β-SBA-15 composite catalyst
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Direct synthesis of microporous-mesoporous zeolite-β-SBA-15 (ZBS-15) composite catalyst from the synthetic precursors of SBA-15and zeolite-β seeds under acidic hydrothermal conditions through the simultaneous self-assembly of mesoporous silica SBA-15 and zeolite-β has been accomplished and characterized the ZBS-15 catalyst by XRD, N2 sorption, FT-IR, TPD of ammonia and SEM techniques. The activity of the ZBS-15 composite catalyst for the nitration of benzenes under solvent-free conditions has been investigated, which revealed that there is a significant synergistic influence of both zeolite-β and SBA-15 materials on the activity of the ZBS-15 catalyst.
- Ganjala, Venkata Siva Prasad,Neeli, Chinna Krishna Prasad,Pramod, Chodimella Venkata,Khagga, Mukkanti,Rao, Kamaraju Seetha Rama,Burri, David Raju
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-
- Bismuth triflate catalyzed mononitration of aromatic compounds with N 2O5
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This page isvestigated that bismuth triflate catalysed the nitration of a range of simple aromatic compounds in good to excellent yields at 0-30 °C within 2 h using N2O5 and the catalyst can be recycled without apparent loss of activity. Mechanistic insights demonstrate that triflic acid is generated and that, at least, when two competing catalytic cycles are operating at the same time: a rapid one involving triflic acid and a slower one involving the bismuth triflate.
- Qian, Hua,Wang, Ya,Liu, Dabin,Lv, Chunxu
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p. 509 - 512
(2014/05/20)
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- Regioselective dinitration of simple aromatics over zeolite Hβ/nitric acid/acid anhydride systems
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Various nitration systems comprising nitric acid, acid anhydride and zeolite H￡] in the absence of solvent are described. Direct double nitration of toluene with a nitric acid, propanoic anhydride and zeolite Hβ system has been developed to give 2,4-dinitrotoluene in 98% yield, with a 2,4-:2,6-dinitrotoluene ratio of 123:1. This system also nitrates activated mono-substituted benzenes (anisole and phenetole) and moderately activated mono-substituted benzenes (ethylbenzene and propylbenzene) to give mainly 2,4-dinitro derivatives. The zeolite can be recovered, regenerated and reused to give almost the same yield as that given when fresh zeolite is used. ARKAT-USA, Inc.
- Smith, Keith,Alotaibi, Mohammad Hayal,El-Hiti, Gamal A.
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p. 107 - 123
(2014/04/17)
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- Ipso-Nitrosation of arylboronic acids with chlorotrimethylsilane and sodium nitrite
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Nitroso compounds are versatile reagents in synthetic organic chemistry. Herein, we disclose a feasible protocol for the ipso-nitrosation of aryl boronic acids using chlorotrimethylsilane-sodium nitrite unison as nitrosation reagent system.
- Prakash, G.K. Surya,Gurung, Laxman,Schmid, Philipp Christoph,Wang, Fang,Thomas, Tisa Elizabeth,Panja, Chiradeep,Mathew, Thomas,Olah, George A.
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p. 1975 - 1978
(2014/04/03)
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- Regioselective mononitration of chlorobenzene using caprolactam-based Br?nsted acidic ionic liquids
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Three kinds of Br?nsted acidic ionic liquids caprolactam benzenesulfonate ([CP]BSA), caprolactam hydrosulfate ([CP]HSO4) and caprolactam p-toluenesulfonate ([CP]pTSA) were synthesized. The structures of the ILs were confirmed by 1HNM
- Zhang, Cun,Yu, Mei-Jing,Pan, Xiao-Yu,Wu, Guo,Jin, Liang,Gao, Wei-Dan,Du, Meng,Zhang, Jun-Chao
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p. 101 - 105
(2014/01/06)
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