- 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.
- -
-
Paragraph 0082-0084; 0097-0099
(2022/04/08)
-
- Method for pipeline continuous fluorination with fluorine salt as fluorine source
-
The method comprises the following steps: dissolving a fluorine salt in an aqueous polar aprotic solvent as reaction liquid A, dissolving an aryl (heterocyclic) chloride in a polar aprotic solvent as reaction liquid B, and reacting a polar aprotic solvent in the reaction liquid A with a polar aprotic solvent of the reaction liquid B. The reaction medium consisting of the preheated reaction liquid A and the preheated reaction liquid B enters the reaction coil for a fluorination reaction, and the resulting product from the reaction coil is subjected to post-treatment to obtain the product. The method has the characteristics of no need of adding a phase transfer catalyst, continuous production, low production cost and the like.
- -
-
Paragraph 0056-0091; 0095-0096; 0098; 0100-0105
(2021/10/27)
-
- Method for efficiently synthesizing fluorine-containing compound
-
The invention discloses a method for efficiently synthesizing a fluorine-containing compound, and relates to the field of fluorine-containing compound synthesis. The method is a method for generating a corresponding fluorine atom substituted fluorine-containing compound by reacting aromatic chloride or activated chloride serving as a raw material with potassium fluoride under the action of a novel catalyst. The method disclosed by the invention has the advantages of good product selectivity, high efficiency, mild reaction conditions, simplicity and convenience in operation, convenience in application and the like.
- -
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Paragraph 0068-0070
(2021/06/26)
-
- Preparation method of fluorine-containing aryl compound
-
The invention relates to the field of organic synthesis, and especially relates to a preparation method of a fluorine-containing aryl compound. The invention provides a preparation method of a compound as shown in a formula 1. The preparation method comprises the following steps: fluorination reaction: reacting a compound as shown in a formula 2 with alkali metal fluoride in the presence of a phase transfer catalyst to prepare the compound as shown in the formula 1. According to the preparation method of the fluorine-containing aryl compound provided by the invention, a reaction system does not contain a solvent, the boiling point of the phase transfer catalyst is relatively high, solvent interference is avoided during rectification or short steaming after the reaction is finished, the distillation yield is high, and the product purity is good.
- -
-
Paragraph 0118-0125
(2021/06/12)
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- 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.
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p. 25841 - 25847
(2021/08/09)
-
- Photoinduced Iron-Catalyzed ipso-Nitration of Aryl Halides via Single-Electron Transfer
-
A photoinduced iron-catalyzed ipso-nitration of aryl halides with KNO2 has been developed, in which aryl iodides, bromides, and some of aryl chlorides are feasible. The mechanism investigations show that the in situ formed iron complex by FeSO4, KNO2, and 1,10-phenanthroline acts as the light-harvesting photocatalyst with a longer lifetime of the excited state, and the reaction undergoes a photoinduced single-electron transfer (SET) process. This work represents an example for the photoinduced iron-catalyzed Ullmann-type couplings.
- Wu, Cunluo,Bian, Qilong,Ding, Tao,Tang, Mingming,Zhang, Wenkai,Xu, Yuanqing,Liu, Baoying,Xu, Hao,Li, Hai-Bei,Fu, Hua
-
p. 9561 - 9568
(2021/08/06)
-
- 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)
-
- 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)
-
- Nucleophilic Fluorination of Heteroaryl Chlorides and Aryl Triflates Enabled by Cooperative Catalysis
-
Aryl and heteroaryl fluorides are growing to be dominant motifs in pharmaceuticals and agrochemicals, yet they are rare in both nature and commodity chemicals. As a consequence, there is an increasingly urgent need to develop mild, cost-effective, and scalable methods for fluorination. The most straightforward route to synthesize aryl fluorides is through the halide exchange "halex"reaction, but conditions, cost, and atom economy preclude most available methods from large-scale manufacturing processes. We report a new approach that leverages the cooperative action of 18-crown-6 ether and tetramethylammonium chloride to catalytically access the reactivity of tetramethylammonium fluoride and achieve halex fluorinations under mild conditions with operational ease. The described methodology readily converts both heteroaryl chlorides and aryl triflates to their corresponding (hetero)aryl fluorides in high yields and purities.
- Hong, Cynthia M.,Whittaker, Aaron M.,Schultz, Danielle M.
-
p. 3999 - 4006
(2021/03/09)
-
- 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
-
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
-
supporting information
p. 5680 - 5686
(2021/08/16)
-
- 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.
- -
-
Paragraph 0030-0032; 0048-0062
(2020/11/10)
-
- 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.
- -
-
Page/Page column 36; 41; 46; 64
(2020/05/28)
-
- 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
-
-
- Novel manufacturing method of fluoro-aryl compounds and derivatives thereof
-
The invention relates to a novel method of manufacturing fluoro-aryl compounds and derivatives thereof, in particular, fluorobenzene and derivatives thereof. The production environment of the manufacturing method is environmentally friendly. The shortages of a conventional method are overcome through a simple and beneficial mode. Compared with the prior art, the provided method is more effective,more environmentally friendly, and more energy saving. The method is used to produce core fluorinated aromatic compounds, preferably, core fluorinated fluorobenzene. On one aspect, the invention provides a method, which is advantages in industry and uses HF and a halogenated benzene precursor to prepare fluorobenzene and hydrogen halide. Moreover, the invention provides chlorobenzene as the primary raw material to prepare fluorobenzene, which is an important material in industry, and a beneficial, unexpected and simple application of chlorobenzene. In the prior art, the provided application ofchlorobenzene is unknown.
- -
-
Paragraph 0201-0205; 0216-0218
(2020/01/25)
-
- First Study of the Thermal and Storage Stability of Arenediazonium Triflates Comparing to 4-Nitrobenzenediazonium Tosylate and Tetrafluoroborate by Calorimetric Methods
-
Herein, for the first time, using isothermal flow calorimetry and differential scanning calorimetry (DSC)/thermal gravimetric analysis (TGA), we have determined the thermal decomposition energies for the number of solid arenediazonium triflates comparing to 4-nitrobenzene tosylate and 4-nitrobenzentetrafluoroborate. The kinetics of thermal decomposition, activation energies, and half-lives of the studied diazonium salts (DSs) were found. Using gas chromatography-mass spectrometry (MS) and liquid chromatography-MS, we have elucidated the products formed during thermolysis of the investigated DSs. By density functional theory quantum chemical calculations at the B3LYP/aug-cc-pVDZ level of theory, we simulated the thermodynamics of decomposition reactions proceeding via substitution of the diazonium group by corresponding nucleophiles. The method applied predicted the decomposition energies of all the studied compounds fairly precise, except for 2-nitrobenzene diazonium triflate. It has been found that 4-nitrobenzene diazonium triflate has increased storage stability under normal conditions comparing to the corresponding tosylate and tetrafluoroborate. The experimental and theoretical results demonstrated that comparing to DSC/TGA, isothermal flow calorimetry more adequately reflects the energetics of the thermal decomposition of DSs and their storage stability under normal conditions.
- Bondarev, Alexander A.,Naumov, Evgeny V.,Kassanova, Assiya Zh.,Krasnokutskaya, Elena A.,Stankevich, Ksenia S.,Filimonov, Victor D.
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p. 2405 - 2415
(2019/10/11)
-
- A convenient room temperature ipso-nitration of arylboronic acid catalysed by molecular iodine using zirconium oxynitrate as nitrating species: An experimental and theoretical investigation
-
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
-
-
- Preparation and characterization of a novel silica-KF composite and facile fluorination of aromatic substrates
-
A novel silica-KF reagent prepared by hydrolyzing tetraethyl orthosilicate in the presence of KF for fluorination of activated aromatic compounds has been reported. The reagent, as characterized by techniques such as SEM-EDX, XRD and IR spectroscopy, is shown to have potassium cations entrapped inside the silica matrix whereas fluoride anions remain on the surface. Reaction of activated chlorinated aromatic substrates with this silica-KF leads to formation of Meisenheimer complex, either in situ or isolable, finally resulting in regioselective fluorinated aromatics.
- Patel, Sagar S.,Bochare, Machhindra D.,Degani, Mariam S.
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p. 20095 - 20100
(2018/12/13)
-
- 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)
-
- Ipso-nitration of arylboronic acids with copper nitrate and trifluoroace-tic acid
-
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
-
p. 891 - 894
(2018/11/06)
-
- Synthesis of nitroolefins and nitroarenes under mild conditions
-
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)
-
- Base-Catalyzed Aryl-B(OH)2 Protodeboronation Revisited: From Concerted Proton Transfer to Liberation of a Transient Aryl Anion
-
Pioneering studies by Kuivila, published more than 50 years ago, suggested ipso protonation of the boronate as the mechanism for base-catalyzed protodeboronation of arylboronic acids. However, the study was limited to UV spectrophotometric analysis under acidic conditions, and the aqueous association constants (Ka) were estimated. By means of NMR, stopped-flow IR, and quenched-flow techniques, the kinetics of base-catalyzed protodeboronation of 30 different arylboronic acids has now been determined at pH > 13 in aqueous dioxane at 70 °C. Included in the study are all 20 isomers of C6HnF(5-n)B(OH)2 with half-lives spanning 9 orders of magnitude: a and Sδ values, kinetic isotope effects (2H, 10B, 13C), linear free-energy relationships, and density functional theory calculations, we have identified a mechanistic regime involving unimolecular heterolysis of the boronate competing with concerted ipso protonation/C-B cleavage. The relative Lewis acidities of arylboronic acids do not correlate with their protodeboronation rates, especially when ortho substituents are present. Notably, 3,5-dinitrophenylboronic acid is orders of magnitude more stable than tetra-and pentafluorophenylboronic acids but has a similar pKa.
- Cox, Paul A.,Reid, Marc,Leach, Andrew G.,Campbell, Andrew D.,King, Edward J.,Lloyd-Jones, Guy C.
-
supporting information
p. 13156 - 13165
(2017/09/26)
-
- Nucleophilic deoxyfluorination of phenols via aryl fluorosulfonate intermediates
-
This report describes a method for the deoxyfluorination of phenols with sulfuryl fluoride (SO2F2) and tetramethylammonium fluoride (NMe4F) via aryl fluorosulfonate (ArOFs) intermediates. We first demonstrate that the reaction of ArOFs with NMe4F proceeds under mild conditions (often at room temperature) to afford a broad range of electronically diverse and functional group-rich aryl fluoride products. This transformation was then translated to a one-pot conversion of phenols to aryl fluorides using the combination of SO2F2 and NMe4F. Ab initio calculations suggest that carbon-fluorine bond formation proceeds via a concerted transition state rather than a discrete Meisenheimer intermediate.
- Schimler, Sydonie D.,Cismesia, Megan A.,Hanley, Patrick S.,Froese, Robert D.J.,Jansma, Matthew J.,Bland, Douglas C.,Sanford, Melanie S.
-
p. 1452 - 1455
(2017/02/10)
-
- Synthetic method of aryl halide taking aryl carboxylic acid as raw material
-
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.
- -
-
Paragraph 0079
(2018/01/03)
-
- METHOD FOR AROMATIC FLUORINATION
-
Disclosed is a fluorination method comprising providing an aryl fluorosuifonate and a fluorinating reagent to a reaction mixture; and reacting the aryl fluorosuifonate and the fluorinating reagent to provide a fluorinated aryl species. Also disclosed is a fluorination method comprising providing, a salt comprising a cation and an aryloxyiate, and SO2F2 to a reaction mixture; reacting the SO2F2 and the ammonium salt to provide a fluorinated aryl species. Further disclosed a fluorination method comprising providing a compound having the structure Ar-OH to a reaction mixture; where A is an aryl or heteroaryl; providing SO2F2 to the reaction mixture; providing a fluorinating reagent to the reaction mixture; reacting the SO2F2, the fluorinating reagent and the compound having the structure Ar-OH to provide a fluorinated aryl species having the structure Ar-F.
- -
-
Paragraph 0047-0049
(2017/12/18)
-
- Organocatalytic oxidation of substituted anilines to azoxybenzenes and nitro compounds: Mechanistic studies excluding the involvement of a dioxirane intermediate
-
An organocatalytic and environmentally friendly approach for the selective oxidation of substituted anilines was developed. Utilizing a 2,2,2-trifluoroacetophenone-mediated oxidation process, substituted anilines can be transformed into azoxybenzenes, while a simple treatment with MeCN and H2O2 leads to the corresponding nitro compounds, providing user-friendly protocols that can be easily scaled up. Various substitution patterns and functional groups were tolerated leading to products in high to excellent yields. Mechanistic studies utilizing HRMS provide clear evidence for the distinct mechanistic intermediates that are involved. This study constitutes an indirect proof excluding the involvement of a dioxirane intermediate in the green organocatalytic oxidation, utilizing 2,2,2-trifluoroacetophenone as the catalyst.
- Voutyritsa, Errika,Theodorou, Alexis,Kokotou, Maroula G.,Kokotos, Christoforos G.
-
supporting information
p. 1291 - 1298
(2017/06/06)
-
- 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)
-
- A New Synthesis of 2-Aminoindoles and 6-Aminopyrrolo[3,2- d ]pyrimidines from π-Deficient 1,2-Dihaloarenes and Geminal Enediamines
-
An efficient approach for the synthesis of fused 2-aminopyrroles via geminal enediamines and π-deficient 1,2-dihaloarenes is presented. The two-step methodology includes aromatic nucleophilic substitution of the activated halogen of dihaloarene with enediamine C-nucleophilic center followed by Cu-catalyzed intramolecular N-arylation. This approach allows access to a variety of 2-amino-6-nitroindoles and 6-aminopyrrolo[3,2-d]pyrimidines (including N-mono- and N,N-disubstituted) in moderate and good yields under mild conditions.
- Mishina, Maria S.,Ivanov, Alexander Yu.,Lobanov, Pavel S.,Dar'In, Dmitrii V.
-
supporting information
p. 2851 - 2862
(2016/08/30)
-
- 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)
-
- Copper-Mediated Oxidative Fluorination of Aryl Stannanes with Fluoride
-
A regiospecific method for the oxidative fluorination of aryl stannanes using tetrabutylammonium triphenyldifluorosilicate (TBAT) and copper(II) triflate is described. This reaction is robust, uses readily available reagents, and proceeds via a stepwise protocol under mild conditions (60 °C, 3.2 h). Broad functional group tolerance, including arenes containing protic and nucleophilic groups, is demonstrated.
- Gamache, Raymond F.,Waldmann, Christopher,Murphy, Jennifer M.
-
supporting information
p. 4522 - 4525
(2016/09/28)
-
- Transition-metal-free synthesis of thiocyanato- or nitro-arenes through diaryliodonium salts
-
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
-
p. 963 - 970
(2016/07/07)
-
- A simple protocol for Cu-catalyzed protodecarboxylation of (hetero)aromatic carboxylic acids
-
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
-
supporting information
p. 3014 - 3018
(2016/05/09)
-
- 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)
-
- 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)
-
- A Fluorinated Ligand Enables Room-Temperature and Regioselective Pd-Catalyzed Fluorination of Aryl Triflates and Bromides
-
A new biaryl monophosphine ligand (AlPhos, L1) allows for the room-temperature Pd-catalyzed fluorination of a variety of activated (hetero)aryl triflates. Furthermore, aryl triflates and bromides that are prone to give mixtures of regioisomeric aryl fluorides with Pd-catalysis can now be converted to the desired aryl fluorides with high regioselectivity. Analysis of the solid-state structures of several Pd(II) complexes, as well as density functional theory (DFT) calculations, shed light on the origin of the enhanced reactivity observed with L1.
- Sather, Aaron C.,Lee, Hong Geun,De La Rosa, Valentina Y.,Yang, Yang,Müller, Peter,Buchwald, Stephen L.
-
supporting information
p. 13433 - 13438
(2015/11/09)
-
- DIGITAL MICROFLUIDIC PLATFORM FOR RADIOCHEMISTRY
-
Disclosed herein are methods of performing microchemical reactions and electro-wetting-on-dielectric devices (EWOD devices) for use in performing those reactions. These devices and method are particularly suited for preparing radiochemical compounds, particularly compounds containing 18F.
- -
-
Paragraph 0086-0098
(2015/07/27)
-
- 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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- 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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- Studying regioisomer formation in the pd-catalyzed fluorination of aryl triflates by deuterium labeling
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Isotopic labeling has been used to determine that a portion of the desired product in the Pd-catalyzed fluorination of electron-rich, non-ortho-substituted aryl triflates results from direct C-F cross-coupling. In some cases, formation of a Pd-aryne intermediate is responsible for producing undesired regioisomers. The generation of the Pd-aryne intermediate occurs primarily via ortho-deprotonation of a L·Pd(Ar)OTf (L = biaryl monophosphine) species by CsF and thus competes directly with the transmetalation step of the catalytic cycle. Deuterium labeling studies were conducted with a variety of aryl triflates.
- Milner, Phillip J.,Kinzel, Tom,Zhang, Yong,Buchwald, Stephen L.
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supporting information
p. 15757 - 15766
(2015/02/02)
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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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p. 1726 - 1728
(2014/03/21)
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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 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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- Aromatic fluoro-de-triazenation with boron trifluoride diethyl etherate under non-protic acid conditions
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Fluoro-de-triazenation of 3,3-diethyl-1-aryltriazenes can be achieved by conventional or under microwave heating in carbon tetrachloride, in the presence of boron trifluoride diethyl etherate without any protic acid to avoid corresponding unwanted byproduct formation.
- Kovac, Mitja,Anderluh, Marko,Vercouillie, Johnny,Guilloteau, Denis,Emond, Patrick,Mavel, Sylvie
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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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p. 2197 - 2202
(2013/03/14)
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- Preparation, catalytic performance and theoretical study of porous sulfated binary metal oxides shell (SO42 -/M1xO y-M2xOy) using pollen grain templates
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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
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- Regioselective nitration of aromatics with nanomagnetic solid superacid SO42-/ZrO2-MxOy-Fe 3O4 and its theoretical studies
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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
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p. 310 - 317
(2013/08/23)
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- Fluorination of aryl boronic acids using acetyl hypofluorite made directly from diluted fluorine
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Aryl boronic acids or pinacol esters containing EDG were converted in good yields and fast reactions to the corresponding aryl fluorides using the readily obtainable solutions of AcOF. In reactions with aryl boronic acids containing EWG at the para position, there are two competing forces: one directing the fluorination to take place ortho to the boronic acid and the other, toward an ipso substitution. With EWG meta to the boronic acid, substitution ipso to the boron moiety takes place in good yields.
- Vints, Inna,Gatenyo, Julia,Rozen, Shlomo
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p. 11794 - 11797
(2014/01/06)
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- Cu(OTf)2-mediated fluorination of aryltrifluoroborates with potassium fluoride
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This Communication describes the Cu(OTf)2-mediated fluorination of aryltrifluoroborates with KF. The reaction proceeds under mild conditions (at 60 C over 20 h) and shows a broad substrate scope and functional group tolerance. The Cu is proposed to play two separate roles in this transformation: (1) as a mediator for the aryl-F coupling and (2) as an oxidant for accessing a proposed CuIII(aryl)(F) intermediate.
- Ye, Yingda,Schimler, Sydonie D.,Hanley, Patrick S.,Sanford, Melanie S.
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supporting information
p. 16292 - 16295
(2013/12/04)
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- Synthesis of functionalized aryl fluorides using organolithium reagents in flow microreactors
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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
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supporting information
p. 705 - 708
(2013/05/08)
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- Copper-catalyzed hydrodefluorination of fluoroarenes by copper hydride intermediates
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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
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supporting information
p. 3203 - 3207
(2013/04/23)
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- Highly regioselective dinitration of toluene over reusable zeolite Hβ
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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.
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p. 244 - 247
(2013/02/22)
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