- Poly-N-bromosulfonamide-melamine as a novel brominating reagent for regioselective ipso-bromination of arylboronic acids
-
A practical synthetic method for the synthesis of aryl bromide was developed through regioselective bromination of boronic acid in the presence of poly-N-bromosulfonamide-melamine (PBBSM). In this regard, a novel heterogeneous support, cross-linked poly sulfonamide-melamine, has been successfully synthesized to stabilize bromine with high surface functional group density (6.6?mmol Br+/g). The prepared reagent is a novel brominating reagent that combines the effective functions of N-bromosulfonamide, N-bromosulfonamide-melamine, and melamine groups. The structure of PBBSM was characterized using XRD, FT–IR, 1H NMR, TGA, FE-SEM, EDX, and TGA analysis. Graphic abstract: [Figure not available: see fulltext.]
- Alavinia, Sedigheh,Ghorbani-Vaghei, Ramin
-
p. 1269 - 1276
(2021/08/27)
-
- Direct bromodeboronation of arylboronic acids with CuBr2 in water
-
An efficient and practical method has been developed for the preparation of aryl bromides via the direct bromodeboronation of arylboronic acids with CuBr2 in water. This strategy provides several advantages, such as being ligand-free, base-free, high yielding, and functional group tolerant.
- Tang, Yan-Ling,Xia, Xian-Song,Gao, Jin-Chun,Li, Min-Xin,Mao, Ze-Wei
-
supporting information
(2021/01/05)
-
- Structure-based design of highly selective 2,4,5-trisubstituted pyrimidine CDK9 inhibitors as anti-cancer agents
-
Cyclin-dependent kinases (CDKs) are a family of Ser/Thr kinases involved in cell cycle and transcriptional regulation. CDK9 regulates transcriptional elongation and this unique property has made it a potential target for several diseases. Due to the conserved ATP binding site, designing selective CDK9 inhibitors has been challenging. Here we report our continued efforts in the optimization of 2,4,5-tri-substituted pyrimidine compounds as potent and selective CDK9 inhibitors. The most selective compound 30m was >100-fold selective for CDK9 over CDK1 and CDK2. These compounds showed broad anti-proliferative activities in various solid tumour cell lines and patient-derived chronic lymphocytic leukaemia (CLL) cells. Decreased phosphorylation of the carboxyl terminal domain (CTD) of RNAPII at Ser-2 and down-regulation of anti-apoptotic protein Mcl-1 were confirmed in both the ovarian cancer model A2780 and patient-derived CLL cells.
- Shao, Hao,Foley, David W.,Huang, Shiliang,Abbas, Abdullahi Y.,Lam, Frankie,Gershkovich, Pavel,Bradshaw, Tracey D.,Pepper, Chris,Fischer, Peter M.,Wang, Shudong
-
supporting information
(2021/02/16)
-
- 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
-
-
- Metal- and base-free synthesis of aryl bromides from arylhydrazines
-
An efficient method was developed to synthesize brominated aromatic compounds from arylhydrazine hydrochlorides by using BBr3 in DMSO/CPME (cyclopentyl methyl ether) under air at 80 °C for 1 h without the use of bases or metal catalysts. In particular, this method could be carried out satisfactorily using electron-withdrawing groups to afford aryl bromides in a moderate to excellent yields.
- Phuc Tran, Dat,Nomoto, Akihiro,Mita, Soichiro,Dong, Chun-ping,Kodama, Shintaro,Mizuno, Takumi,Ogawa, Akiya
-
supporting information
(2020/05/08)
-
- ipso-Bromination/iodination of arylboronic acids: Poly(4-vinylpyridine)-Br2/I2 complexes as safe and efficient reagents
-
Poly(4-vinyl pyridine) supported bromine/iodine complexes were prepared and probed for ipso-bromination/iodination of arylboronic acids. These solid complexes with catalytic amount of additive are found to be safe and efficient reagent system for the ipso-bromination/iodination. The reaction occurs under mild conditions and tolerates various functional groups resulting in products with high selectivity and yields.
- Fu, Fang,Gurung, Laxman,Czaun, Miklos,Mathew, Thomas,Prakash, G.K. Surya
-
supporting information
(2019/08/26)
-
- Base promoted peroxide systems for the efficient synthesis of nitroarenes and benzamides
-
A useful and efficient approach for the synthesis of nitroarenes from several aromatic amines (including heterocycles) using peroxide and base has been developed. This oxidative reaction is very easy to handle and afforded the products in good yields. Formation of benzamides from benzylamine was also successfully carried out with this metal-free catalytic system in good to excellent yields.
- Gupta, Sampa,Ansari, Alisha,Sashidhara, Koneni V.
-
supporting information
(2019/09/07)
-
- Pd-Catalyzed Decarboxylative Ortho-Halogenation of Aryl Carboxylic Acids with Sodium Halide NaX Using Carboxyl as a Traceless Directing Group
-
A highly regioselective Pd-catalyzed carboxyl directed decarboxylative ortho-C-H halogenation of cheap o-nitrobenzoic acids with NaX (X = I, Br) under aerobic conditions has been established. The utility of the method has been demonstrated by the gram-scale reaction and derivatization of the product. Experimental results have confirmed Pd and Bi played critical roles in the transformation and indicated the transformation might proceed via 2-halo-6-nitrobenzoic acid derivative intermediate.
- Fu, Zhengjiang,Jiang, Yongqing,Wang, Shuiliang,Song, Yuanyuan,Guo, Shengmei,Cai, Hu
-
supporting information
p. 3003 - 3007
(2019/05/10)
-
- A general electrochemical strategy for the Sandmeyer reaction
-
Herein we report a general electrochemical strategy for the Sandmeyer reaction. Using electricity as the driving force, this protocol employs a simple and inexpensive halogen source, such as NBS, CBrCl3, CH2I2, CCl4, LiCl and NaBr for the halogenation of aryl diazonium salts. In addition, we found that these electrochemical reactions could be performed using anilines as the starting material in a one-pot fashion. Furthermore, the practicality of this process was demonstrated in the multigram scale synthesis of aryl halides using highly inexpensive graphite as the electrode. A series of detailed mechanism studies have been performed, including radical clock and radical scavenger study, cyclic voltammetry analysis and in situ electron paramagnetic resonance (EPR) analysis.
- Liu, Qianyi,Sun, Beiqi,Liu, Zheng,Kao, Yi,Dong, Bo-Wei,Jiang, Shang-Da,Li, Feng,Liu, Guoquan,Yang, Yang,Mo, Fanyang
-
p. 8731 - 8737
(2018/12/10)
-
- PROCESS FOR THE PREPARATION OF ORGANIC BROMIDES
-
The present invention provides a process for the preparation of organic bromides, by a radical bromodecarboxylation of carboxylic acids with a bromoisocyanurate.
- -
-
Paragraph 00138
(2017/07/28)
-
- PROCESS FOR THE PREPARATION OF ORGANIC HALIDES
-
The present invention provides a halo-de-carboxylation process for the preparation of organic chlorides, organic bromides and mixtures thereof, from their corresponding carboxylic acids, using a chlorinating agent selected from trichloroisocyanuric acid (TCCA), dichloroisocyanuric acid (DCCA), or combination thereof, and a brominating agent.
- -
-
Paragraph 00122
(2017/08/01)
-
- A highly efficient heterogeneous copper-catalyzed chlorodeboronation of arylboronic acids leading to chlorinated arenes
-
A highly efficient heterogeneous copper-catalyzed chlorodeboronation of arylboronic acids with inexpensive N-chlorosuccinimide (NCS) was achieved in MeCN in the presence of 10 mol% of l-proline-functionalized MCM-41-immobilized copper(i) complex [MCM-41-l-proline-CuCl] under mild conditions, yielding a variety of aryl chlorides in excellent yields. This method proved to be tolerant of a broad range of functional groups and particularly useful for the conversion of electron-deficient arylboronic acids to aryl chlorides, a transformation that is inefficient without copper catalysis. This heterogeneous copper catalyst can be recovered by a simple filtration of the reaction solution and recycled for at least 10 times without any decreases in activity.
- He, Wen,Zhang, Rongli,Cai, Mingzhong
-
p. 764 - 770
(2017/01/13)
-
- NH4I/tert-butyl hydroperoxide-promoted oxidative C–N cleavage of tertiary amines leading to nitroaromatic compounds
-
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
-
p. 504 - 508
(2017/10/03)
-
- Reactivity of alkali and alkaline earth metal tetrafluorobromates towards aromatic compounds and pyridine
-
The bromination activity of tetrafluorobromates of alkali and alkali-earth metals increases in the order KBrF4, CsBrF4, RbBrF4and Ba(BrF4)2. The most active tetrafluorobromate—Ba(BrF4)2is able to selectively brominate the deactivated aromatic compounds nitrobenzene and 4-nitrotoluene, but not the activated compounds benzene and toluene. In all cases bromination of methyl groups of methylbenzenes does not occur. Ba(BrF4)2forms the known complex C6H5N·BrF3when reacted with pyridine. Due to dilution by inert BaF2, this pyridine-based complex is air stable and can be considered as safer and more convenient reagent in comparison with the original fluorobromates; it can selectively brominate benzene and toluene in contrast with tetrafluorobromates.
- Sobolev, Vasily I.,Filimonov, Victor D.,Ostvald, Roman V.,Radchenko, Vyacheslav B.,Zherin, Ivan I.
-
p. 120 - 123
(2016/11/17)
-
- PROCESS FOR PREPARING A COMPOUND BY A NOVEL SANDMEYER-LIKE REACTION USING A NITROXIDE RADICAL COMPOUND AS A REACTION CATALYST
-
The present invention provides a novel process for preparing a substituted aromatic compound such as an aromatic halo compound or a salt thereof through a transformation reaction of an aromatic diazonium salt from an aromatic amino compound at stable high yields utilizing a novel Sandmeyer-like reaction using a nitroxide radical compound as a reaction catalyst.
- -
-
Paragraph 0023; 0024
(2013/06/26)
-
- Halogenation and DNA cleavage via thermally stable arenediazonium camphorsulfonate salts
-
A series of stable arenediazonium camphorsulfonate salts (2a-2j) were synthesized by simple diazotization of several aromatic amines in the presence of sodium nitrite and camphorsulfonic acid. All the new arenediazonium camphorsulfonates, which were characterized by multinuclear (1H and 13C) NMR, IR, DSC, and X-ray diffraction analysis (2e and 2f) provide unambiguous proof for the molecular structures of 2e and 2f. The efficient application of these salts in halogenation reactions was studied in solvent and solvent-free conditions and the DNA cleavage activity was also assessed. These arenediazonium camphorsulfonate salts are noticed as efficient DNA cleaving agents.
- Vajpayee, Vaishali,Moon, Mi Eun,Lee, Sunmi,Ravikumar, Sambandam,Kim, Hyunuk,Ahn, Byungchan,Choi, Seoyoon,Hong, Soon Ho,Chi, Ki-Whan
-
p. 3511 - 3517
(2013/04/23)
-
- 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
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p. 310 - 317
(2013/08/23)
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- Tribromoisocyanuric acid in trifluoroacetic acid: An efficient system for smooth brominating of moderately deactivated arenes
-
Moderately deactivated arenes are efficiently brominated by the reaction with tribromoisocyanuric acid (0.34 mol equiv) in trifluoroacetic acid at room temperature in 48-85% isolated yield. This medium avoids the polybromination of the substrate, observed in the same reaction performed in 98% H 2SO4. Georg Thieme Verlag Stuttgart · New York.
- De Almeida, Leonardo S.,De Mattos, Marcioc. S.,Esteves, Pierre M.
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p. 603 - 606
(2013/04/10)
-
- Mild bromination of unreactive aromatic compounds
-
N,N,N', N'-Tetrabromobenzene-1,3-disulfonamide and poly(N, N'-dibromo-N-ethylene-benzene-1,3-disulfonamide) in concentrated H 2SO4 can be used as efficient reagents for the mild bromination of unreactive arenes at room temperature, under solvent-free conditions, in good yields.
- Ghorbani-Vaghei, Ramin,Shahbazi, Hajar,Veisi, Hojat
-
experimental part
p. 2325 - 2327
(2012/07/14)
-
- Tetraflic acid (1,1,2,2-Tetrafluoroethanesulfonic acid, HC 2F4SO3H) and gallium tetraflate as effective catalysts in organic synthesis
-
Tetraflic acid offers ample acidity for various organic reactions that require high acidity. Its gallium(III) salt is an efficient catalyst under mild condtions for synthetic transformations such as the ketonic Strecker reaction for the synthesis of fluorinated α-amino nitriles and condensation- cyclzation reactions using suitable fluoro ketones and 1,2-disubstituted benzenes for the direct preparation of 5-membered or 6-membered fluorinated heterocycles. Copyright
- Prakash, G. K. Surya,Mathew, Thomas,Panja, Chiradeep,Kulkarni, Aditya,Olah, George A.,Harmer, Mark A.
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p. 2163 - 2171
(2012/11/07)
-
- Copper-catalyzed halogenation of arylboronic acids
-
In this Letter, a copper-catalyzed halogenation of arylboronic acids was described. This reaction tolerates a variety of functional groups, providing aromatic halides with good yields. It represents a facile and mild procedure to aryl halides.
- Zhang, Guangyou,Lv, Guanglei,Li, Liping,Chen, Fan,Cheng, Jiang
-
experimental part
p. 1993 - 1995
(2011/04/25)
-
- Synthesis and isomerization studies of cyclotrisazobiphenyl
-
We report an efficient synthesis of cyclotris[(E)-3′-(biphenyl-3- yldiazenyl)] compounds (CTBs). An unsubstituted CTB molecule is accessible in four steps in 10% yield overall, whereas a hexa(methoxymethyl ether) CTB analogue was prepared in nine steps (26% yield). The final macrocyclization step was accomplished in up to 80% yield by using a metal-template effect. Furthermore, the photochromic properties were investigated, and all four isomers were detected and characterized by NMR spectroscopy. A strong influence from the solvent and the irradiation wavelength on the switching process was observed. Irradiation in pyridine yielded the highest amount of the all-Z isomer in the photostationary state. For a full conversion to the all-E isomer, the reaction has to be heated to 45°C. The isomerization to the all-E isomer is slow at room temperature, with a half-life time of the all-Z isomer of more than nine days in dimethyl sulfoxide (DMSO). Conditions were established to access each possible isomer as the major component in the photostationary state.
- Reuter, Raphael,Wegner, Hermann A.
-
supporting information; experimental part
p. 2987 - 2995
(2011/05/05)
-
- Copper-catalyzed chlorination of functionalized arylboronic acids
-
"Chemical Equation Presented" A mild, efficient, Cu(I)-catalyzed method for the conversion of arylboronic acids to aryl chlorides Is reported. This method is particularly useful for the conversion of electron-deficient arylboronic acids to aryl chlorides, a transformation that is inefficient In the absence of Cu catalysis.
- Wu, Hong,Hynes Jr., John
-
supporting information; experimental part
p. 1192 - 1195
(2010/04/27)
-
- Efficient and economic halogenation of aryl amines via arenediazonium tosylate salts
-
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
-
experimental part
p. 7418 - 7422
(2010/10/01)
-
- An expeditious and environmentally benign preparation of aryl halides from aryl amines by solvent-free grinding
-
An efficient solvent-free methodology for conversion of various aryl amines into bromides and chlorides via arenediazonium tosylate salts under grinding conditions is disclosed. This new methodology not only avoids the use of strong acids and expensive reagents for diazotization-halogenation reactions, but also decreases the amount of organic waste from the reaction process.
- Moon, Mi Eun,Choi, Younghwa,Lee, Young Min,Vajpayee, Vaishali,Trusova, Marina,Filimonov, Victor D.,Chi, Ki-Whan
-
scheme or table
p. 6769 - 6771
(2011/03/17)
-
- CYCLOPENTADIONE DERIVED HERBICIDES
-
Compounds of formula (I), wherein the substituents are as defined in claim 1, are suitable for use as herbicides.
- -
-
Page/Page column 55; 56
(2010/08/08)
-
- Thallium(III) oxide as an oxidative reagent in organic chemistry
-
Oxidative properties of thallium(III) oxide in various organic reactions were studied. Oxidative bromination of organic compounds in Tl2O 3-KBr-trifluoroacetic acid system was carried out. New synthetic method for preparation of diphenylthallium salts from phenylhydrazine and thallium(III) oxide was developed.
- Gun'kin
-
scheme or table
p. 451 - 454
(2010/08/04)
-
- Gold-catalysis: Reactions of organogold compounds with electrophiles
-
Different arylgold(I), one alkynylgold(I), and one vinylgold(I) triphenylphosphane complexes were subjected to electrophilic halogenation reagents. With N-chlorosuccinimid, N-bromosuccinimid, and N-iodosuccinimid as well as the Barluenga reagent, selectively halogenated compounds were obtained. Trifluoroacetic acid, as a source of protons, leads to a clean protodeauration. With N-fluorobenzenesulfonimide or Selectfluor, exclusively a homocoupling was observed. For the precursor of the vinylgold(I) complex, a similar oxidative coupling could be induced by gold(III) chloride. Reactions with silicon or tin electrophiles failed. CSIRO 2010.
- Hashmi, A. Stephen K.,Ramamurthi, Tanuja Dondeti,Todd, Matthew H.,Tsang, Althea S.-K.,Graf, Katharina
-
experimental part
p. 1619 - 1626
(2011/09/12)
-
- Superelectrophilic bromination of deactivated aromatic rings with tribromoisocyanuric acid-an experimental and DFT study
-
The reaction of deactivated arenes with tribromoisocyanuric acid (TBCA) in 98% H2SO4 produced bromoarenes in good yields. The acidity of the medium controls the strength of the brominating agent and the amount of polybrominated products. DFT calculations at B3LYP/6-311++G** level showed that the protonated TBCA (a superelectrophilic species) can easily transfer Br+ to deactivated arenes, in order to decrease internal charge-charge repulsion.
- de Almeida, Leonardo S.,Esteves, Pierre M.,de Mattos, Marcio C.S.
-
experimental part
p. 3001 - 3004
(2009/09/28)
-
- Silica sulphuric acid as an efficient catalyst for the catalytic and metal-free oxidation of aromatic amines to their corresponding nitro compounds with sodium perborate under micellar media
-
Electron-donating substituted anilines were converted to their corresponding nitro compounds with sodium perborate in the presence of a catalytic amount of silica sulphuric acid under micellar media in moderate to good yields.
- Habibi, Davood,Zolfigol, Mohammad A.,Safaiee, Maliheh
-
-
- Halo- and azidodediazoniation of arenediazonium tetrafluoroborates with trimethylsilyl halides and trimethylsilyl azide and Sandmeyer-type bromodediazoniation with Cu(I)Br in [BMIM][PF6] ionic liquid
-
(Chemical Equation Presented) Reaction of [ArN2][BF4] salts immobilized in [BMIM][PF6] ionic liquid (IL) with TMSX (X = I, Br) and TMSN3 represents an efficient method for the preparation of iodo-, bromo-, and azido-derivatives via dediazoniation. The reactions can also be effected starting with ArNH2 by in situ diazotization with [NO][BF4] followed by reaction with TMSX or TMSN3. Depending on the substituents on the benzenediazonium cation, competing fluorodediazoniation (ArF formation) and hydrodediazoniation (ArH formation) were observed. Dediazoniation with TMSN3 and with TMSI generally gave the highest chemoselectivity toward ArN3 and ArI formation. The IL was recycled and reused up to 5 times with no appreciable decrease in the conversions. Multinuclear NMR monitoring of the interaction of [ArN 2][BF4]/TMSX, [BMIM][PF6]/TMSX, and [BMIM][PF6]/TMSX/[ArN2][BF4] indicated that TMSF is formed primarily via [ArN2][BF4]/ TMSX, generating [ArN2][X] in situ, which gives ArX on dediazoniation. Competing formation of ArF in Sandmeyer-type bromodediazoniation of [ArN 2][BF4] with Cu(I)Br immobilized in the IL points to significant involvement of heterolytic dediazoniation.
- Hubbard, Abigail,Okazaki, Takao,Laali, Kenneth K.
-
p. 316 - 319
(2008/09/17)
-
- The conversion of phenols to the corresponding aryl halides under mild conditions
-
Mild, novel procedures have been developed for the syntheses of aryl halides from the corresponding phenols in modest to good yields via boronate ester intermediates.
- Thompson, Alicia L. S.,Kabalka, George W.,Akula, Murthy R.,Huffman, John W.
-
p. 547 - 550
(2007/10/03)
-
- Palladium-catalyzed arylation of linear and cyclic polyamines
-
The palladium-catalyzed arylation of polyandries is investigated and it is shown that the C-N coupling reaction for a given substrate is strongly dependent on the nature and the concentration of the catalytic system, as well as the nature of the base employed. The arylation of the primary amino group is favored when both primary and secondary amines are present; selective arylation is then possible without using any protecting group. The reaction of dihalobenzenes with polyamines gives the monoamination products in good yields without any significant formation of diamino compounds or reduced derivatives, unlike what is observed when monoamines are used. The extent of polyarylation of polyamines as a function of the excess of aryl halide and the nature and the amount of catalyst is also studied. Finally, N-arylation of a macrocyclic tetraamine (cyclam) is performed by using an appropriate catalytic system. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005.
- Beletskaya, Irina P.,Bessmertnykh, Alla G.,Averin, Alexei D.,Denat, Franck,Guilard, Roger
-
p. 261 - 280
(2007/10/03)
-
- Facile Synthesis of 2-Bromo-3-fluorobenzonitrile: An Application and Study of the Halodeboronation of Aryl Boronic Acids
-
A scaleable synthesis of 2-bromo-3-fluorobenzonitrile via the NaOMe-catalyzed bromodeboronation of 2-cyano-6-fluorophenylboronic acid was developed. The generality of this transformation was demonstrated through the halodeboronation of a series of aryl boronic acids. Both aryl bromides and aryl chlorides were formed in good to excellent yields when the corresponding aryl boronic acid was treated with 1,3-dihalo-5,5-dimethylhydantoin and 5 mol % NaOMe.
- Szumigala Jr., Ronald H.,Devine, Paul N.,Gauthier Jr., Donald R.,Volante
-
p. 566 - 569
(2007/10/03)
-
- ipso-nitration of arylboronic acids with chlorotrimethylsilane-nitrate salts
-
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.
-
p. 2205 - 2207
(2007/10/03)
-
- N-halosuccinimide/BF3-H2O, efficient electrophilic halogenating systems for aromatics
-
N-Halosuccinimides (NXS, 1) are efficiently activated in trifluoromethanesulfonic acid and BF3-H2O, allowing the halogenations of deactivated aromatics. Because BF3-H2O is more economic, easy to prepare, nonoxidizing, and offers sufficiently high acidity (-H0 ≈ 12, only slightly lower than that of trifluoromethanesulfonic acid), an efficient new electrophilic reagent combination of NXS/BF3-H2O has been developed. DFT calculations at the B3LYP/6-311++G**//B3LYP/6-31G* level suggest that protonated N-halosuccinimides undergo further protosolvation at higher acidities to reactive superelectrophilic species capable either in the transfer of X+ from the protonated forms of NXS to the aromatic substrate or in forming a highly reactive and solvated X+ which would readily react with the aromatic substrates. Structural aspects of the BF 3-H2O complex have also been investigated.
- Prakash, G. K. Surya,Mathew, Thomas,Hoole, Dushyanthi,Esteves, Pierre M.,Wang, Qi,Rasul, Golam,Olah, George A.
-
p. 15770 - 15776
(2007/10/03)
-
- Halogenation of Aromatic Compounds by N-chloro-, N-bromo-, and N-iodosuccinimide
-
An efficient and mild method for the halogenation of aromatic compounds using N-chloro-, N-bromo-, and N-iodosuccinimide in the presence of NH 4NO3 or FeCl3 in acetonitrile was developed.
- Tanemura, Kiyoshi,Suzuki, Tsuneo,Nishida, Yoko,Satsumabayashi, Koko,Horaguchi, Takaaki
-
p. 932 - 933
(2007/10/03)
-
- Bromination by means of sodium monobromoisocyanurate (SMBI)
-
A variety of aromatic compounds with both activating and deactivating substituents were brominated with sodium monobromoisocyanurate (SMBI) 1, diethyl ether, diethyl ether-methanesulfonic acid, trifluoroacetic acid, or sulfuric acid were employed as solvents. Thus nitrobenzene was conveniently brominated in sulfuric acid, benzene was readily monobrominated in diethyl ether-methanesulfonic acid, and phenol was selectively brominated at the ortho position under mild conditions in refluxing diethyl ether. With substituents that are easily protonated, trifluoroacetic acid may be employed as solvent in the reaction with 1, in contrast NBS was ineffective in trifluoroacetic acid. This renders 1 a superior reagent relative to NBS. In addition to aromatics, alkenes, ketones and esters were also brominated with 1. Diethyl malonate was brominated with 1 and then subjected to a Bingel reaction with NaH to afford the desired methanofullerene in reasonable yield.
- Okada, Yukihiro,Yokozawa, Masanori,Akiba, Miwa,Oishi, Kazuhiko,O-Kawa, Kyoji,Akeboshi, Tomohiro,Kawamura, Yasuo,Inokuma, Seiichi,Nakamura, Yosuke,Nishimura, Jun
-
p. 2506 - 2511
(2007/10/03)
-
- Pyridinium dichlorobromate: A new stable brominating agent for aromatic compounds
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Pyridinium dichlorobromate (PyHBrCl2, 1) is a new example of iminium-trihalide complexes. The compound is prepared from pyridine and chlorine in the presence of aqueous hydrogen bromide. The crystalline trihalide is quite stable and acts as a safe source of positive bromine. It shows a remarkable reactivity towards aromatic compounds compared with other bromine complexes. It is also considered as a potential source for bromine chloride BrCl.
- Muathen, Hussni A.
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p. 169 - 171
(2007/10/03)
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- A fast and mild method for the nitration of aromatic rings
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The use of N2O5 and a Fe(III) catalyst for the nitration of aromatic rings is described. This methodology is compatible with most functional groups and results in near quantitative yields in 4 min. The reaction conditions are non-oxidising: benzaldehyde and benzyl alcohols are readily nitrated with little or no oxidation (4%) occurring. The addition of the iron catalyst activates the system to such an extent that nitration of an activated aromatic ring, such as toluene, occurs quantitatively at -100°C. This high activity allows compounds with sensitive functional groups such as alkenes to be smoothly nitrated.
- Bak, Radoslaw R.,Smallridge, Andrew J.
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p. 6767 - 6769
(2007/10/03)
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- Regioselective nitration of arylboronic acids
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A convenient and simple regioselective ipso-nitration of arylboronic acids to nitroarenes has been developed. Under certain conditions even dinitro products were isolated.
- Salzbrunn,Simon,Prakash,Petasis,Olah
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p. 1485 - 1487
(2007/10/03)
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- Use of sodium bromate for aromatic bromination: Research and development
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Sodium bromate is a powerful brominating agent for aromatic compounds that contain deactivating substituents. A bromination process, in which sodium bromate was utilized, was optimized on laboratory scale. Addition of a strong acid into a stirred aqueous solution, or slurry, of the substrate and bromate salt at 40-100°C, leads to the decomposition of the bromate ions and production of the active brominating species. Substrates such as nitrobenzene, benzoic acid, and benzaldehyde were brominated in high yields (85-98%) and specificity. The reaction is especially useful for the bromination of disubstituted benzenes, such as 4-nitrofluorobenzene or 4-fluorobenzoic acid. Several substrates, such as dinitrobenzenes or nitrobenzoic acids, did not undergo bromination at all. The main parameters of the reaction and some of its synthetic potential are discussed.
- Groweiss, Amiram
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- Halodediazoniations of dry arenediazonium o-benzenedisulfonimides in the presence or absence of an electron transfer catalyst. Easy general procedures to prepare aryl chlorides, bromides, and iodides
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The paper reports the results of a wide study aimed at preparing aryl chlorides 3 (19 examples), bromides 4 (19 examples), and iodides 5 (9 examples) by halodediazoniation of dry arenediazonium o-benzenedisulfonimides 1 with tetraalkylammonium halides 2. The reactions were carried out in anhydrous acetonitrile at room temperature (~20 °C) in the presence of copper powder and at 60 °C or room temperature without the catalyst. In optimal conditions the yields were from good to excellent (60 reactions, 61- 94% yield), with only a few exceptions (8 reactions, 51-55% yield). A good amount of the o-benzenedisulfonimide (7) was always recovered from the reactions and could then be reused to prepare salts 1. An interesting aspect of this research is the surprising role of the anion of o- benzenedisulfonimide (9) as an electron transfer agent.
- Barbero,Degani,Dughera,Fochi
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p. 3448 - 3453
(2007/10/03)
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- Halo-substituted aminobenzenes prepared by Pd-catalyzed amination
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The selective monoamination of aryl dihalides by primary amines and polyamines in the presence of the Pd2(dba)3/dppf catalytic system and NaOt- Bu provides a convenient method for the synthesis of aminobenzenes substituted at the ortho, meta, or para position of the aryl ring by a halogen atom. Under these conditions the reaction of polyamine compounds having 1,2-diaminoethane or 1,3-diaminopropane moieties proceeds selectively leading to monoaryl-substituted derivatives of polyamines. Moreover, this is a remarkably efficient method to realize the arylation of a primary amine group of polyamines in the presence of a secondary one.
- Beletskaya, Irina P.,Bessmertnykh, Alla G.,Guilard, Roger
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p. 1459 - 1461
(2007/10/03)
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- A convenient new method for the bromination of deactivated aromatic compounds
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Treatment of deactivated aromatic compounds with N-bromosuccinimide in trifluoroacetic acid solvent in the presence of sulfuric acid gave the corresponding monobromoaromatic compounds in good to excellent yields.
- Duan, Jianxin,Zhang, Lian Hao,Dolbier Jr., William R.
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p. 1245 - 1246
(2007/10/03)
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- Mild preparation of haloarenes by ipso-substitution of arylboronic acids with N-halosuccinimides
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Aryl and heteroaryl boronic acids react with N-iodosuccinimide and N-bromosuccinimide to give the corresponding iodo-and bromo- arenes in good to excellent yields. The reaction is usually highly regioselective and yields only the ipso-substituted product. Esters of arylboronic acids react similarly, but less readily.
- Thiebes, Christoph,Prakash, G. K. Surya,Petasis, Nicos A.,Olah, George A.
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p. 141 - 142
(2007/10/03)
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- Lanthanide(III) triflates as recyclable catalysts for atom economic aromatic nitration
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Lanthanide(III) triflates catalyse (1-10 mol%) the nitration of a range of simple aromatic compounds in good to excellent yield using stoichiometric quantities of 69% nitric acid; the only by-product is water and the catalyst can be readily recycled by simple evaporation.
- Waller, Francis J.,Barrett, Anthony G. M.,Braddock, D. Christopher,Ramprasad, Dorai
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p. 613 - 614
(2007/10/03)
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- SELECTIVITY OF NITRATION REACTIONS OF AROMATIC COMPOUNDS ON ZEOLITES H-Y AND H-ZSM-11
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Substrate and positional selectivity in the nitration reaction of benzene and its derivatives (halobenzenes, toluene and o-xylene) by nitric acid and acyl nitrates supported on zeolites H-Y and H-ZSM-11 were studied.The reaction mechanism and effects governing selectivity of the process are discussed.
- Nagy, Sandor M.,Yarovoy, Konstantin A.,Shubin, Vyacheslav G.,Vostrikova, Lidiya A.
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p. 385 - 393
(2007/10/02)
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- Halogenation Using N-Halogenocompounds. II. Acid Catalyzed Bromination of Aromatic Compounds with 1,3-Dibromo-5,5-dimethylhydantoin
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Ring bromination of aromatic compounds using 1,3-dibromo-5,5-dimethylhydantoin in dichloromethane is promoted by the addition of strong acids.Both organic and inorganic acids whose pKa values are lower than -2 showed the promoting effect.This acid-catalyzed bromination is both practical and effective, even for aromatics having electron-withdrawing substituents.
- Eguchi, Hisao,Kawaguchi, Hideichiro,Yoshinaga, Sachiyo,Nishida, Akiko,Nishiguchi, Takeshi,Fujisaki, Shizuo
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p. 1918 - 1921
(2007/10/02)
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