cas 1493-27-2, 1-Fluoro-2-nitrobenzene | Articles data

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Method for synthesizing nitro (hetero) aromatic hydrocarbon
The invention discloses a method for synthesizing nitro (hetero) aromatic hydrocarbon, and belongs to the field of organic synthesis. According to the method, simple (hetero) aromatic hydrocarbon is taken as an initial raw material and is stirred and reacted in an organic solvent at 40-100 DEG C under the action of a nitration reagent, a lewis acid catalyst and protective gas, and nitro (hetero) aromatic hydrocarbon can be obtained. The method provided by the invention has the advantages of cheap and easily available raw materials, mild reaction conditions, simple preparation process, good chemical selectivity, wide substrate application range, easy amplification and the like, has great application potential, and lays a good foundation for industrial production.
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Paragraph 0082-0084; 0097-0099

(2022/04/08)

Radical Decarboxylative Carbometalation of Benzoic Acids: A Solution to Aromatic Decarboxylative Fluorination
Abundant aromatic carboxylic acids exist in great structural diversity from nature and synthesis. To date, the synthetically valuable decarboxylative functionalization of benzoic acids is realized mainly by transition-metal-catalyzed decarboxylative cross couplings. However, the high activation barrier for thermal decarboxylative carbometalation that often requires 140 °C reaction temperature limits both the substrate scope as well as the scope of suitable reactions that can sustain such conditions. Numerous reactions, for example, decarboxylative fluorination that is well developed for aliphatic carboxylic acids, are out of reach for the aromatic counterparts with current reaction chemistry. Here, we report a conceptually different approach through a low-barrier photoinduced ligand to metal charge transfer (LMCT)-enabled radical decarboxylative carbometalation strategy, which generates a putative high-valent arylcopper(III) complex, from which versatile facile reductive eliminations can occur. We demonstrate the suitability of our new approach to address previously unrealized general decarboxylative fluorination of benzoic acids.
Xu, Peng,López-Rojas, Priscila,Ritter, Tobias
supporting information
p. 5349 - 5354
(2021/05/05)

Ipso Nitration of Aryl Boronic Acids Using Fuming Nitric Acid
The ipso nitration of aryl boronic acid derivatives has been developed using fuming nitric acid as the nitrating agent. This facile procedure provides efficient and chemoselective access to a variety of aromatic nitro compounds. While several activating agents and nitro sources have been reported in the literature for this synthetically useful transformation, this report demonstrates that these processes likely generate a common active reagent, anhydrous HNO3. Kinetic and mechanistic studies have revealed that the reaction order in HNO3 is >2 and indicate that the ?NO2 radical is the active species.
Baucom, Kyle D.,Brown, Derek B.,Caille, Seb,Murray, James I.,Quasdorf, Kyle,Silva Elipe, Maria V.
supporting information

(2021/06/30)

Nitration of aromatics with dinitrogen pentoxide in a liquefied 1,1,1,2-tetrafluoroethane medium
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.
p. 25841 - 25847
(2021/08/09)

Catalyst and application thereof in synthesis of aromatic fluorine compounds
The invention belongs to the field of catalyst preparation and application, and particularly relates to a catalyst and application thereof in synthesis of aromatic fluorine compounds. The nickel catalyst is dichloro-bis-(tri-cyclohexylphosphine) nickel, and the molecular formula of the nickel catalyst is Ni (Py3) 2Cl2. The nickel catalyst is applied to catalyzing inorganic fluoride to replace aromatic chloride to synthesize fluoride. The catalyst has the advantages of easily available reagents, simple catalyst synthesis, simple operation conditions, low reaction temperature, high reaction yield and less time consumption.
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Paragraph 0033-0035

(2020/11/10)

N-Nitroheterocycles: Bench-Stable Organic Reagents for Catalytic Ipso-Nitration of Aryl- And Heteroarylboronic Acids
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
supporting information

(2020/03/30)

Low-temperature and highly efficient liquid-phase catalytic nitration of chlorobenzene with NO2: Remarkably improving the para-selectivity in O2-Ac2O-Hβ composite system
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
(2020/02/26)

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

(2020/05/28)

Preparation method of substituted nitrobenzene compound
The invention discloses a preparation method of a substituted nitrobenzene compound. The method comprises the following steps: carrying out a decarboxylation reaction as shown below on a compound II under the action of alkali in a solvent at the temperature of 150 to 250 DEG C to obtain a compound I; the alkali is one or more of carbonates and bicarbonates of alkali metals. Compared with some metal-catalyzed decarboxylation methods, the preparation method of the substituted nitrobenzene compound has the advantages of simple operation, low production cost, convenient post-treatment and high yield, and more application values in industrial production.
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Paragraph 0046-0049

(2019/03/29)

Transition-State Interactions in a Promiscuous Enzyme: Sulfate and Phosphate Monoester Hydrolysis by Pseudomonas aeruginosa Arylsulfatase
Pseudomonas aeruginosa arylsulfatase (PAS) hydrolyzes sulfate and, promiscuously, phosphate monoesters. Enzyme-catalyzed sulfate transfer is crucial to a wide variety of biological processes, but detailed studies of the mechanistic contributions to its catalysis are lacking. We present linear free energy relationships (LFERs) and kinetic isotope effects (KIEs) of PAS and analyses of active site mutants that suggest a key role for leaving group (LG) stabilization. In LFERs PASWT has a much less negative Br?nsted coefficient (βleaving groupobs-Enz = 0.33) than the uncatalyzed reaction (βleaving groupobs = 1.81). This situation is diminished when cationic active site groups are exchanged for alanine. The considerable degree of bond breaking during the transition state (TS) is evidenced by an 18Obridge KIE of 1.0088. LFER and KIE data for several active site mutants point to leaving group stabilization by active site K375, in cooperation with H211. 15N KIEs and the increased sensitivity to leaving group ability of the sulfatase activity in neat D2O (βleaving groupH-D = +0.06) suggest that the mechanism for S-Obridge bond fission shifts, with decreasing leaving group ability, from charge compensation via Lewis acid interactions toward direct proton donation. 18Ononbridge KIEs indicate that the TS for PAS-catalyzed sulfate monoester hydrolysis has a significantly more associative character compared to the uncatalyzed reaction, while PAS-catalyzed phosphate monoester hydrolysis does not show this shift. This difference in enzyme-catalyzed TSs appears to be the major factor favoring specificity toward sulfate over phosphate esters by this promiscuous hydrolase, since other features are either too similar (uncatalyzed TS) or inherently favor phosphate (charge).
Van Loo, Bert,Berry, Ryan,Boonyuen, Usa,Mohamed, Mark F.,Golicnik, Marko,Hengge, AlVan C.,Hollfelder, Florian
p. 1363 - 1378
(2019/03/11)

HNO3/HFIP: A Nitrating System for Arenes with Direct Observation of π-Complex Intermediates
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)

Reactions of aromatic compounds with xenon difluoride
Reactions of substituted benzenes C6H5R (R = Me, F, Cl, Br, CF3, NO2) with xenon difluoride in the presence of boron trifluoride–diethyl ether complex in weakly acidic (1,1,1,3,3-pentafluorobutane) and weakly basic media (acetonitrile) have been studied. These reactions lead to the formation of fluorobenzene derivatives FC6H4R (isomer mixture) together with isomeric difluorobenzenes and fluorinated and non-fluorinated biphenyls. The results have been compared with previously reported data obtained in other solvents using other catalysts.
Bardin,Adonin, N. Yu.
p. 1400 - 1407
(2016/11/29)

One-Pot C?H Functionalization of Arenes by Diaryliodonium Salts
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
p. 8928 - 8932
(2016/07/26)

Regioselective mononitration of aromatic compounds with N2O5 by acidic ionic liquids via continuous flow microreactor
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
p. 513 - 516
(2016/01/20)

Metal-free chemoselective ortho -C(sp2)-F bond hydroxylation and N-trifluoroacylation of fluoroarylamines for domino synthesis of 2-(N-trifluoroacyl)aminophenols
Abstract A novel chemoselective reaction for the formation of C-O bonds by C(sp2)-F bond cleavage and concomitant N-trifluoroacylation of fluoroanilines using trifluoroacetic acid and Oxone is presented. This domino reaction gives o-hydroxy-N-trifluoroacetanilides in good yields under metal-free conditions in a single step. Selective ortho-directed monohydroxylation and N-trifluoroacylation of 2- and 6-fluoro- or 2,6-difluoro-substituted anilines takes place in this transformation.
Venkateswarlu, Vunnam,Balgotra, Shilpi,Aravinda Kumar,Vishwakarma, Ram A.,Sawant, Sanghapal D.
supporting information
p. 1258 - 1262
(2015/06/02)

A novel transition metal free [bis-(trifluoroacetoxy)iodo]benzene (PIFA) mediated oxidative ipso nitration of organoboronic acids
A mild, convenient and transition metal free methodology for oxidative ipso nitration of diversely functionalized organoboronic acids, including heteroaryl- and alkylboronic acids, has been developed at ambient temperature using a combination of [bis-(trifluoroacetoxy)]iodobenzene (PIFA) - N-bromosuccinimide (NBS) and sodium nitrite as the nitro source. It is anticipated that the reaction proceeds through in situ generation of NO2 and O-centred organoboronic acid radicals followed by the formation of an O-N bond via combination of the said radicals. Finally transfer of the NO2 group to the aryl moiety occurs through 1,3-aryl migration to provide the nitroarenes.
Chatterjee, Nachiketa,Bhatt, Divya,Goswami, Avijit
supporting information
p. 4828 - 4832
(2015/05/05)

Fluorination of aromatic compounds with xenon difluoride in the presence of boron trifluoride etherate
Fluorination of benzene with the XeF2 - BF3?Et2O system in acetonitrile at low temperatures affords fluorobenzene in 18% yield, the conversion of benzene being 92%. The rest products are di-, tri-, tetra-, and polyphenyls with different fluorination pattern. Toluene and chloro- and bromobenzenes are fluorinated predominantly at the ortho and para positions. Fluorination of 4-nitroanisole affords 2-fluoro-4-nitroanisole in 73% yield.
Fedorov,Zubarev,Mortikov, V. Yu.,Rodinovskaya,Shestopalov
p. 1049 - 1052
(2016/02/09)

Poly(4-vinylpyridine)-nitrating mixture complex (PVP-NM): Solid nitrating mixture equivalent for safe and efficient aromatic nitration
Friedel-Crafts type aromatic nitration has served as an indispensable reaction within both industrial and academic applications. However, growing concern over the use of copious amounts of strong acids has prompted the search for more environmentally friendly alternatives. Polymer-bound Bronsted acids, on the other hand, have been shown useful as convenient alternatives to liquid acids. Nitric acid and sulfuric acids have, therefore, been combined, both individually and as a mixture, with poly(4-vinylpyridine). The new solid acid systems have been used to nitrate both activated and deactivated arenes under mild conditions and proved to be effective nitrating agent.
Surya Prakash,Gurung, Laxman,Glinton, Kevin E.,Belligund, Kavita,Mathew, Thomas,Olah, George A.
supporting information
p. 3446 - 3451
(2015/06/25)

Regioselective dinitration of simple aromatics over zeolite Hβ/nitric acid/acid anhydride systems
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.
p. 107 - 123
(2014/04/17)

Bismuth triflate catalyzed mononitration of aromatic compounds with N 2O5
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
p. 509 - 512
(2014/05/20)

Synthesis of functionalized aryl fluorides using organolithium reagents in flow microreactors
Flow on: Flow microreactors enable the generation of aryl lithium compounds and subsequent electrophilic fluorination with NFSI and N-fluorosultam. The reaction can be successfully accomplished to synthesize various aryl fluorides involving an electron-withdrawing, an electron-donating, and a sterically hindered functional group in good yields. Copyright
Nagaki, Aiichiro,Uesugi, Yuki,Kim, Heejin,Yoshida, Jun-Ichi
supporting information
p. 705 - 708
(2013/05/08)

Copper-catalyzed hydrodefluorination of fluoroarenes by copper hydride intermediates
Breaking bad: Efficient copper-catalyzed C-F bond activation has been achieved by replacing fluorine with hydrogen. A copper hydride is proposed as the active intermediate, which proceeds through a nucleophilic attack on the fluorocarbon, as determined by experimental and theoretical results (see structure; C gray, H white, Cu light red, F light blue; distances in ?).
Lv, Hongbin,Cai, Yuan-Bo,Zhang, Jun-Long
supporting information
p. 3203 - 3207
(2013/04/23)

Highly regioselective dinitration of toluene over reusable zeolite Hβ
A nitration system comprising nitric acid, propanoic anhydride, and zeolite Hβ has been developed for dinitration of toluene to give 2,4-dinitrotoluene in 98% yield, with a 2,4-:2,6-dinitrotoluene ratio of over 120. This represents the most selective quantitative method for 2,4-dinitration of toluene; the catalyst is reusable, solvent is not needed, and an aqueous work-up is not required.
Smith, Keith,Alotaibi, Mohammad Hayal,El-Hiti, Gamal A.
p. 244 - 247
(2013/02/22)

Regioselective nitration of aromatics with nanomagnetic solid superacid SO42-/ZrO2-MxOy-Fe 3O4 and its theoretical studies
A series of micro- and nanosulfated zirconia loaded on Fe3O 4 or other metal oxides (SO42-/ZrO 2-MxOy-Fe3O4 (M=Ti 4+, V5+, and Zn2+)) was prepared, characterized, and used in nitration. The nitration conditions with these solid superacids were then optimized to achieve the best regioselectivity and improve the performances of the catalysts as well. In the experimental results, SZTF (SO42-/ZrO2-TiO2-Fe 3O4) showed excellent catalytic activity and it increased the surface area of SO42-/ZrO2 by up to 15 %. The increase not only facilitated the generation of NO2+, but also provided more opportunities for metal ions to interact with aromatic compounds. With chlorobenzene as substrate, theoretical research on its geometric parameters, electron clouds, and electron spin density was used to investigate the interaction between transition metals and chlorobenzene.
Wang, Peng Cheng,Zhu, Jie,Liu, Xiang,Lu, Ting Ting,Lu, Ming
p. 310 - 317
(2013/08/23)

Preparation of heteropoly acid based amphiphilic salts supported by nano oxides and their catalytic performance in the nitration of aromatics
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
p. 2197 - 2202
(2013/03/14)

Preparation, catalytic performance and theoretical study of porous sulfated binary metal oxides shell (SO42 -/M1xO y-M2xOy) using pollen grain templates
Porous micro-sized particles of binary metal oxide (SO4 2 -/M1xOy-M2xOy) shell were prepared by template-directed synthesis method employing HCl-treated pollen grains. With 150 m2/g high surface area, these solid acids could provide more acid sites and thus obtain better catalytic activity. Using aromatic nitration as the typical reaction, their catalytic performances were evaluated and showed a significant improvement in both conversion and regioselectivity. Then, with chlorobenzene as substrate, theoretical studies were performed to investigate the interaction between transition metals and chlorobenzene. The results showed that the excellent para-selectivity was closely relative to the metal ion in these solid acids.
Wang, Peng Cheng,Yao, Kai,Zhu, Jie,Liu, Xiang,Lu, Ting Ting,Lu, Ming
p. 90 - 95
(2013/07/26)

Phosphonium ionic liquids as highly thermal stable and efficient phase transfer catalysts for solid-liquid Halex reactions
Trihexyl (tetradecyl) phosphonium tetrafluoroborate was found to be an active catalyst for the introduction of fluoride by nucleophilic aromatic substitution. With a decomposition temperature above 300 °C, this ionic liquid is suitable for reactions at high temperatures. The addition of 1 mol% of the ionic liquid relative to KF increased the initial rate for the fluorination of 1,2-dichloro-4-nitrobenzene six-fold compared to the uncatalysed reaction. The highest reaction rate was observed at 20 mol% ionic liquid relative to KF. Ease of handling without the need for stringent drying conditions and reuseability make this ionic liquid a useful phase transfer catalyst.
Fan, Ao,Chuah, Gaik-Khuan,Jaenicke, Stephan
p. 300 - 304
(2013/01/15)

Rare earth metal triflates catalyzed electrophilic nitration using N 2O5
A mild, efficient and eco-friendly process for the electrophilic nitration is described using N2O5 as a green nitrating agent in the presence of rare earth metal triflates [RE(OTf)3] under mild conditions.
Ma, Xiao Ming,Li, Bin Dong,Lu, Ming,Lv, Chun Xu
experimental part
p. 73 - 76
(2012/03/26)

Selective nitration of aromatic compounds catalyzed by Hβ zeolite using N2O5
A selective and efficient process for the electrophilic nitration is described using N2O5 as a green nitrating agent, Hβ zeolite as a solid acid catalyst and shape controlling agent under mild conditions.
Ma, Xiao Ming,Li, Bin Dong,Chen, Lei,Lu, Ming,Lv, Chun Xu
scheme or table
p. 809 - 812
(2012/08/08)

Regioselectivity nitration of aromatics with N2O5 in PEG-based dicationic ionic liquid
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
supporting information; experimental part
p. 1452 - 1455
(2011/05/16)

Ethylammonium nitrate (EAN)/Tf2O and EAN/TFAA: Ionic liquid based systems for aromatic nitration
Acting as in situ sources of triflyl nitrate (TfONO2) and trifluoroacetyl nitrate (CF3COONO2), the EAN/Tf 2O and EAN/TFAA systems, generated via metathesis in the readily available ethylammonium nitrate (EAN) ionic liquid as solvent, are powerful electrophilic nitrating reagents for a wide variety of aromatic and heteroaromatic compounds. Comparative nitration experiments indicate that EAN/Tf2O is superior to EAN/TFAA for nitration of strongly deactivated systems. Both systems exhibit low substrate selectivity (K T/KB = 5-10) in (Figure presented) between values reported for covalent nitrates and preformed nitronium salts.
Aridoss, Gopalakrishnan,Laali, Kenneth K.
experimental part
p. 8088 - 8094
(2011/11/13)

An efficient and eco-friendly MoO3-SiO2 solid acid catalyst for electrophilic aromatic nitration with N2O5
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
experimental part
p. 1814 - 1820
(2012/03/08)

A mild and efficient method for nucleophilic aromatic fluorination using tetrabutylammonium fluoride as fluorinating reagent
Anhydrous tetrabutylammonium fluoride (TBAFanh.) has been found to be a highly efficient fluorinating reagent for nucleophilic aromatic fluorinations such as fluorodenitration or halogen exchange (Halex) reaction. The products were formed in high to excellent yields under surprisingly mild reaction conditions and no phenol or ether side-products were detected in these reactions.
Hu, Yu Feng,Luo, Jun,Lü, Chun Xu
experimental part
p. 151 - 154
(2010/11/18)

Lanthanide Bis[(trifluoromethyl)sulfonyl]imides as reusable catalysts for mononitration of substituted benzenes in ionic liquids
Lanthanide bis[(trifluoromethyl)sulfonyl]imides as a kind of effective catalyst were used in quaternary ammonium ionic liquids to afford a useful new method for the nitration of substituted benzenes with concentrated nitric acid (95%) as nitrating agent. The less expensive lanthanum bis[(trifluoromethyl) sulfonyl]imide was found to be the most effective catalyst employed in the ionic liquid tributylammonium bis[(trifluoromethyl)sulfonyl]imide. The lanthanum bis[(trifluoromethyl)sulfonyl]-imide/tributylammonium bis[(trifluoromethyl) sulfonyl]imide system demonstrated high catalytic activity for the nitration of halobenzenes and rendered good to excellent yields. This catalyst/ionic liquid system could be recovered by simple procedures and recycled for at least 5 times.
Wang, Shuojin,Jiang, Shaojie,Nie, Jin
experimental part
p. 1939 - 1945
(2011/02/28)

Efficient phosphorus catalysts for the halogen-exchange (Halex) reaction
New families of monomeric to dendritic, and monocationic to multicationic (PNP) compounds have been prepared and tested as catalysts in halogen exchange (Halex) reactions. Some of them allow an increase in the efficiency of these reactions which are performed in some cases under the mildest conditions reported up to now.
Lacour, Marie-Agnes,Zablocka, Maria,Duhayon, Carine,Majoral, Jean-Pierre,Taillefer, Marc
supporting information; experimental part
p. 2677 - 2682
(2009/10/20)

Polymer-supported ytterbium perfluorooctanesulfonate [Yb(OPf)3]: A recyclable catalyst for organic reactions
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
p. 524 - 528
(2008/12/22)

A polymer imidazole salt as phase-transfer catalyst in halex fluorination irradiated by microwave
A new imidazole polymer salt was synthesized in order to develop a high efficiency phase-transfer catalyst for multi-phase reactions. The polymer salt was prepared easily by co-polymerization of 1-1′-(1,4-butamethylene)bis(imidazole) and 1,2-dibromoethane, and has the properties of excellent chemical and thermal stability and high ionic conductivity. It was applied as phase-transfer catalyst in the fluorination of chloronitrobenzenes under the irradiation of microwave and gave excellent yields of corresponding fluoronitrobenzenes. In addition, the enhanced mechanism of microwave was studied and found "non-thermal" effect was a great factor.
Liang, Zheng Yong,Lü, Chun Xu,Luo, Jun,Dong, Li Bin
p. 608 - 611
(2008/01/01)

METHODS OF IDENTIFYING MODULATORS OF BROMODOMAINS
The present invention features compounds of the following general formula (I) wherein R1 is selected from the group consisting of hydrogen, lower alkyl, aryl, aralkyl; substituted aralkyl, heteroaryl; substituted heteroaryl, phenyl, SO2, NH2, NO2, SO2, CH2, CH2CH3, OCH3, OCOCH3, CH2COCH3, and OH, CN and halogen; R2 is selected from the group consisting of hydrogen; lower alkyl, aryl, phenyl, aralkyl; substituted aralkyl, heteroaryl; substituted heteroaryl, SO2 NH2NH3+NO2, SO2, CH3, CH2CH3, OCH3, OCOCH3, CH2COCH3, and OH, halogen, carboxy, and alkoxy; X is selected from the group consisting of lower alkyl, SO2, NH, NO2, , CH3, CH2CH3, OCH3, OCOCH3, CH2COCH3, and OH, carboxy, and alkoxy; and n is an integer from O to 10 and their pharmaceutically acceptable salts of acids or bases as well as pharmaceutical compositions comprising these compounds. The invention further provides methods for preventing or inhibiting the binding of bromodomains to acetyl-lysine residues of proteins and methods for treating HIV infection and HW related disease. The present invention also features compounds of the following general formula (II) wherein: R1R2 and R3 are independently selected from the group consisting of hydrogen; lower alkyl, aryl, phenyl, aralkyl; substituted aralkyl, heteroaryl; substituted heteroaryl, SO2, NH2, NH3+ NO2, SO2, CH3, CH2CH3, OCH3, OCOCH3, CH2COCH3, OH, SH, halogen, carboxy; and R4 is selected from the group consisting of lower alkyl, aryl, SO2, NH, NO2, CH3, CH2CH3, OCH3, OCOCH3, CH2COCH3, OH, carboxy, and alkoxy as well as pharmaceutical compositions comprising these compounds. The invention further provides methods for preventing or inhibiting the binding of bromodomains to acetyl-lysine residues of proteins and methods f treating HW infection and HIY related disease. The present invention also features compounds of formula (III) wherein R1, R2, R3, R4 R5, and R6 are independently selected from the group consisting of hydrogen; lower alkyl, aryl, phenyl, aralkyl; substituted aralkyl, heteroaryl, substituted heteroaryl, SO2 NH2, NH3+, NO2, SO2, CH3, CH2CH3, OCH3, OCOCH3, CH2COCH3, OCH2CH3, OCH(CH3)2, OCH2COOH, OCHCH3COOH, OCH2COCH3, OCH2CONH2, OCOCH(CH3)2, OCH2CH2OH, OCH2CH2CH3, O(CH2)3CH3, OCHCH3COOCH3, OCH2CON(CH3)2,NH(CH2)3N(CH3)2, NH(CH2)2N(CH3)2, NH(CH2)2OH, NH(CH2)3CH3, NHCH3, SH, halogen, carboxy, and alkoxy as well as pharmaceutical compositions comprising these compounds. The invention further provides methods for preventing or inhibiting the binding of bromodomains to acetyl-lysine residues of proteins and methods for treating HIV infection and HIV related disease.
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Page/Page column 63

(2008/06/13)

BF3·2CF3CH2OH (BF 3·2TFE), an efficient superacidic catalyst for some organic synthetic transformations
BF3 · 2CF3CH2OH complex was found to be a very effective superacidic catalyst comparable in acid strength to at least that of 100% anhydrous sulfuric acid for various acid-catalyzed organic transformations such as isomerizations, rearrangements, ionic hydrogenation of various ketones, and aromatics with triethylsilane and nitration of aromatics with metal nitrate. Studies of the pivalaldehyde-methyl isopropyl ketone rearrangement and the benzopinacol to phenanthrene transformation suggest that the complex has an acidity comparable to that of 100% anhydrous sulfuric acid. The structure and properties of the 1:2 boron trifluoride-trifluoroethanol complex have been further studied using NMR (1H, 13C, 19F, 11B) and DFT calculations at the B3LYP/6- 311++G**//B3LYP/6-31G* level.
Prakash, G. K. Surya,Mathew, Thomas,Marinez, Eric R.,Esteves, Pierre M.,Rasul, Golam,Olah, George A.
p. 3952 - 3958
(2007/10/03)

Indium triflate as a recyclable catalyst for the nitration of aromatic compounds without a halogenated solvent
Indium triflate [In(OTf)3] was found to be excellent catalyst (0.5 or 2.0 mol%) for the mononitration of aromatic compounds using a single equivalent of nitric acid (60 or 90%, 1.0 equiv.) without using a halogenated solvent. The side product is water and the indium triflate catalyst can be readily recovered from the aqueous phase and reused.
Yin, Wan-Po,Shi, Min
p. 549 - 551
(2007/10/03)

Tetrabutylammonium salt induced denitration of nitropyridines: Synthesis of fluoro-, hydroxy-, and methoxypyridines
(Chemical Equation Presented) An efficient method for the synthesis of fluoropyridines via the fluorodenitration reaction is reported. The reaction is mediated by tetrabutylammonium fluoride (TBAF) under mild conditions without undue regard to the presence of water. The fluorodenitration is general for 2- or 4-nitro-substituted pyridines, while 3-nitropyridines require attendant electron-withdrawing groups for the reaction to proceed efficiently. Nitropyridines also undergo hydroxy- and methoxydenitration under mild conditions in the presence of the corresponding tetrabutylammonium species.
Kuduk, Scott D.,DiPardo, Robert M.,Bock, Mark G.
p. 577 - 579
(2007/10/03)

Selective small molecules blocking HIV-1 tat and coactivator PCAF association
Development of drug resistance from mutations in the targeted viral proteins leads to continuation of viral production by chronically infected cells, contributing to HIV-mediated immune dysfunction. Targeting a host cell protein essential for viral reproduction, rather than a viral protein, may minimize the viral drug resistance problem as observed with HIV protease inhibitors. We report here the development of a novel class of N1-aryl-propane-1,3-diamine compounds using a structure-based approach that selectively inhibit the activity of the bromodomain of the human transcriptional co-activator PCAF, of which association with the HIV trans-activator Tat is essential for transcription and replication of the integrated HIV provirus. Copyright
Zeng, Lei,Li, Jiaming,Muller, Michaela,Yan, Sherry,Mujtaba, Shiraz,Pan, Chongfeng,Wang, Zhiyong,Zhou, Ming-Ming
p. 2376 - 2377
(2007/10/03)

A polymer onium acting as phase-transfer catalyst in halogen-exchange fluorination promoted by microwave
A polymerized quaternary ammonium salt polydiallyldimethylammonium chloride, exhibiting high stability to heat and base, was prepared and applied as phase-transfer catalyst (PTC) in halogen-exchange (Halex) fluorination of chloronitrobenzenes to give excellent yields of corresponding fluoronitrobenzenes. Dimethyl sulfoxide was found to be the best solvent when microwave was applied as heating resource.
Luo, Jun,Lü, Chunxu,Cai, Chun,Qü, Wenchao
p. 701 - 704
(2007/10/03)

Novel aminophenyl ketone derivatives
Novel heteroaryl aminophenyl ketone derivatives which are inhibitors of MAP kinases, in particular the p38 MAP kinase, are useful as anti-inflammatory agents in the prophylaxis or treatment of inflammatory diseases or conditions.
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(2008/06/13)

1-Fluoro-2,4,6-trichloro-1,3,5-triazinium tetrafluoroborate: Synthesis, characterization, and ability to effect electrophilic aromatic substitution
The synthesis of 1-fluoro-2,4,6-trichloro-1,3,5-triazinium tetrafluoroborate, [(ClCN)3F]+[BF4] - (1), from (ClCN)3, BF3 and F2 is reported. Compound 1 was shown to be a useful reagent for the quantitative fluorination of aromatic substrates such as benzene, chlorobenzene, nitrobenzene, and methoxybenzene.
Banks, R. Eric,Besheesh, Mohamed K.,Fraenk, Wolfgang,Klap?tke, Thomas M.
p. 229 - 232
(2007/10/03)

Clay supported ammonium nitrate "clayan": A new reagent for selective nitration of arenes
The nitration of activated, deactivated and highly functionalized arenes is described using clay-supported ammonium nitrate in the presence of perchloric acid.
Meshram,Ganesh,Madhavi,Eshwaraiah,Yadav,Gunasekar
p. 2497 - 2503
(2007/10/03)

Ring fluorination of non-activated aromatic compounds
Unsubstituted aromatic compounds and aromatic compounds having one or more electron-withdrawing substituents are fluorinated, preferably in a nitromethane solvent, by contact with tri(halo- or trifluoromethyl) substituted N-fluorotriazinium salts of the following Formula I: wherein three A moieties are independently CR, where each R is independently halogen or trifluoromethyl; two A moieties are independently Z, where each Z is independently nitrogen or a quaternary nitrogen atom and Y is a counterion or group of counterions which are inert to chemical attack by fluorine. Preferably the cation of the salt is 2,4,6-trichloro-1,3,5-triazinium.
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Page 8

(2008/06/13)

Electrophilic fluorination
N-fluorotriazinium salts, especially those of the following Formula I, are electrophilic fluorinating agents useful in fluorinating, preferably in a nitromethane solvent, carbanionic species and/or activated aromatic compounds:wherein three A moieties are independently CR, where each R is, independently, hydrogen, halogen, (primary, secondary or tertiary) amino, hydroxyl, amino, cyano, perfluorothio hydroxysulphonyl, halosulphonyl, hydrocarbyloxysulphonyl,, or a carbon-containing substituent selected from optionally substituted hydrocarbyl, hydrocarbyloxy, hydrocarbyloxycarbonyl, and hydrocarbylthio groups; two A moieties are independently Z, where each Z is independently nitrogen or a quaternary nitrogen atom and Y is a counterion or group of counterions which are inert to chemical attack by fluorine, and oligomers or polymers thereof in which adjacent triazinium moieties are linked by a common R substituent. Preferably the cation of the salt is 2,4,6-trichloro-1,3,5-triazinium.
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Page 14

(2008/06/13)

Perfluorinated rare earth metals catalyzed nitration of aromatic compounds
The nitration of aromatic compounds can be carried out in the presence of perfluorinated rare earth metal catalyst without halogenated organic solvent.
Shi, Min,Cui, Shi-Cong
p. 207 - 209
(2007/10/03)

Preparation process of fluorine substituted aromatic compound
A preparation process of a fluorine substituted aromatic compound comprising reacting an alkali metal or alkali earth metal salt of an aromatic compound having a hydroxy group with an organic fluorinating agent is disclosed. As a representative fluorinating agent, a bis-dialkylamino-difluoromethane compound, for example, 2,2′-difluoro-1,3-dimethylimidazolidine, is exemplified. According to the process, an industrially useful fluorinated aromatic compound, for example, a fluorobenzene, a fluorine substituted benzophenone, a fluorine substituted diarylsulfone can be prepared with ease in economy without specific equipment.
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(2008/06/13)