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Selective Thiocyanation and Aromatic Amination to Achieve Organized Annulation of Enaminone with Thiocyanate
A tandem insertion of thiocyanate to enamine was performed for the regioselective synthesis of multisubstituted benzoimidazo[2,1-b]thiazoles. This method was shown to be effective in addressing the issue of isomerization encountered in common strategies. With a change made to the leading group on the aniline fragment of enamine, the reaction achieved different transformations, thus enabling multisubstituted benzo[4,5]imidazo[2,1-b]thiazoles and thiazoles in satisfactory yields.
Feng, Xukai,Leng, Xin,Li, Jianli,Li, Yao,Liu, Hua,Liu, Lang,Liu, Ping,She, Mengyao,Zhang, Jun,Zhang, Shengyong,Zheng, Tingting
supporting information
p. 8396 - 8401
(2021/11/17)

Ni-NiO heterojunctions: a versatile nanocatalyst for regioselective halogenation and oxidative esterification of aromatics
Herein, we report a facile method for the synthesis of Ni-NiO heterojunction nanoparticles, which we utilized for the nuclear halogenation reaction of phenol and substituted phenols usingN-bromosuccinimide (NBS). A remarkablepara-selectivity was achieved for the halogenated products under semi-aqueous conditions. Interestingly, blocking of thepara-position of phenol offeredortho-selective halogenation. In addition, the Ni-NiO nanoparticles catalyzed the oxidative esterification of carbonyl compounds with alcohol, diol or dithiol in the presence of a catalytic amount of NBS. It was observed that the aromatic carbonyls substituted with an electron-donating group favoured nuclear halogenation, whereas an electron-withdrawing group substitution in carbonyl compounds facilitated the oxidation reaction. In addition, the catalyst was magnetically separated and recycled 10 times. The tuned electronic structure at the Ni-NiO heterojunction controlled selectivity and activity as no suchpara-selectivity was observed with commercially available NiO or Ni nanoparticles.
Bhardwaj, Nivedita,Goel, Bharat,Indra, Arindam,Jain, Shreyans K.,Singh, Ajit Kumar,Tripathi, Nancy
p. 14177 - 14183
(2021/08/16)

5, 10-dihydroindolo [3, 2-b] indole derivative and synthesis method and application thereof
The invention discloses a synthesis method of a 5, 10-dihydroindolo [3, 2-b] indole derivative, the method comprises the following steps: mixing a 2-((2-halogen phenyl) ethynyl)-N, N-dimethylaniline derivative (II), N, N-di-tert-butyl diazacycloketone (III), a palladium catalyst, a monophosphine ligand, alkali and a first organic solvent, and carrying out a diamidation reaction under the protection of inert gas to realize the synthesis of the 5, 10-dihydroindolo [3, 2-b] indole derivative(I). The method is easy to operate, mild in reaction condition and high in reaction yield, and the synthesized 5, 10-dihydroindolo [3, 2-b] indole derivative can be used for preparing an organic light-emitting device.
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Paragraph 0051; 0053-0054

(2021/07/17)

A metal-free aerobic oxidative bromination of anilines and aryl ketones with 2-methylpyridinium nitrate as a reusable ionic liquid
An aerobic oxidative bromination of anilines and aryl ketones catalyzed by recyclable 2-methylpyridinium nitrate ionic liquid is achieved in water using hydrobromic acid as the bromine source and molecular oxygen as the oxidant. The catalytic system shows good efficiency and atom economy.
Li, Ming-Fang,Wang, Jian,Ke, Yong-Xin,Pan, Song-Cheng,Yin, Hong,Du, Wenting,Li, Jing-Hua
p. 267 - 270
(2020/01/08)

Nitromethane as a reagent for the synthesis of 3-nitroindoles from 2-haloarylamine derivatives
A new approach to the synthesis of 3-nitroindoles using palladium-catalyzed arylation of nitromethane with N-(2-bromoaryl)imidates was developed. A convenient and rapid method for cyclization of ethyl N-(2-nitromethylaryl)acetimidates to 2-methyl-3-nitro-1H-indoles was proposed.
Chesnokov,Ageshina,Maryanova,Rzhevskiy,Gribanov,Topchiy,Nechaev,Asachenko
p. 2370 - 2377
(2020/12/31)

Making endo-cyclizations favorable again: A conceptually new synthetic approach to benzotriazoles via azide group directed lithiation/cyclization of 2-azidoaryl bromides
Although benzotriazoles are important and ubiquitous, currently there is only one conceptual approach to their synthesis: bridging the two ortho-amino groups with an electrophilic nitrogen atom. Herein, we disclose a new practical alternative-the endo-cyclization of 2-azidoaryl lithiums obtained in situ from 2-azido-aryl bromides. The scope of the reaction is illustrated using twenty-four examples with a variety of alkyl, alkoxy, perfluoroalkyl, and halogen substituents. We found that the directing effect of the azide group allows selective metal-halogen exchange in aryl azides containing several bromine atoms. Furthermore, (2-bromophenyl)diazomethane undergoes similar cyclization to give an indazole. Thus, cyclizations of aryl lithiums containing an ortho-X = Y = Z group emerge as a new general approach for the synthesis of aromatic heterocycles. DFT computations suggested that the observed endo-selectivity applies to the anionic cyclizations of other functionalities that undergo "1,1-additions" (i.e., azides, diazo compounds, and isonitriles). In contrast, cyclizations with the heteroatomic functionalities that follow the "1,2-addition" pattern (cyanates, thiocyanates, isocyanates, isothiocyanates, and nitriles) prefer the exo-cyclization path. Hence, such reactions expand the current understanding of stereoelectronic factors in anionic cyclizations.
Ageshina, Alexandra A.,Chesnokov, Gleb A.,Topchiy, Maxim A.,Alabugin, Igor V.,Nechaev, Mikhail S.,Asachenko, Andrey F.
supporting information
p. 4523 - 4534
(2019/05/17)

Sodium sulfate-hydrogen peroxide-sodium chloride adduct: selective protocol for the oxidative bromination, iodination and temperature dependent oxidation of sulfides to sulfoxides and sulfones
The regioselective bromination and iodination of unprotected aromatic primary amines using enclathrated hydrogen peroxide as an oxidant under mild conditions has been developed, in which potassium bromide (KBr) and potassium iodide (KI) were used as brominating and iodinating agents, respectively. The adduct shows not only regioselectivity for para- or ortho-isomers but also a remarkable chemoselectivity for monobromination. Selective oxidation of sulfides to sulfoxides and sulfones has also been studied and good to excellent yields of the desired products were obtained. Acetic acid was found to be the solvent of choice for these reactions. This simple method represents an ecologically benign and alternative pathway for the oxidative halogenation of anilines and the oxidation of sulfides to sulfoxides and sulfones.
Gayakwad, Eknath M.,Patel, Khushbu P.,Shankarling, Ganapati S.
supporting information
p. 6001 - 6009
(2019/04/17)

Regulating Transition-Metal Catalysis through Interference by Short RNAs
Herein we report the discovery of a AuI–DNA hybrid catalyst that is compatible with biological media and whose reactivity can be regulated by small complementary nucleic acid sequences. The development of this catalytic system was enabled by the discovery of a novel AuI-mediated base pair. We found that AuI binds DNA containing C-T mismatches. In the AuI–DNA catalyst's latent state, the AuI ion is sequestered by the mismatch such that it is coordinatively saturated, rendering it catalytically inactive. Upon addition of an RNA or DNA strand that is complementary to the latent catalyst's oligonucleotide backbone, catalytic activity is induced, leading to a sevenfold increase in the formation of a fluorescent product, forged through a AuI-catalyzed hydroamination reaction. Further development of this catalytic system will expand not only the chemical space available to synthetic biological systems but also allow for temporal and spatial control of transition-metal catalysis through gene transcription.
Green, Sydnee A.,Montgomery, Hayden R.,Benton, Tyler R.,Chan, Neil J.,Nelson, Hosea M.
supporting information
p. 16400 - 16404
(2019/08/26)

o-xylylene bis(triethyl ammonium tribromide) as a mild and recyclable reagent for rapid and regioselective bromination of anilines and phenols
Background: o-Xylylene bis(triethyl ammonium tribromide) (OXBTEATB) as a recyclable and high bromine containing di-(tribromide) reagent has been employed for the bromination of various organic substrates such as phenol and aniline or its derivatives. This catalyst can be recovered and reused several times. Methods: Aryl bromides shown in Table 1, were easily produced from bromination of aromatic compounds by OXBTEATB. This high-yield process lets the reagents to be recycled and reused. Results: As shown in Table 1, substituted anilines, phenols and β-naphthol were found to be the most reactive and immediately converted to the corresponding mono-brominated products by OXBTEATB. Conclusion: OXBTEATB can be considered a solidified bromine. This novel reagent has variable solubility in different polar protic and aprotic solvents but insoluble in non-polar aprotic solvent. Subsequently, OXBTEATB can be recognized as a more useful brominating and regioselective catalyst than the liquid bromine.
Hemati, Roya,Shahvelayati, Ashraf S.,Yadollahzadeh, Khadijeh
p. 682 - 687
(2018/07/14)

Direct Synthesis of Structurally Divergent Indole Alkaloids from Simple Chemicals
A direct and structurally divergent synthesis of indole alkaloids from very simple 2-vinylanilines, alkynes and TBN via a novel substrate fragmentation/cycloaddition strategy has been developed, which provides an efficient noble-metal-free approach to access a library of highly valuable indole derivatives of tryptamines and tryptamine-related oximes, lactams, and lactones, as well as β-carbolines, spiroindolines, and hexa-hydropyrrolo[2,3-b]indoles.
Shen, Tao,Zhu, Bencong,Lin, Fengguirong,Pan, Jun,Wei, Jialiang,Luo, Xiao,Liu, Jianzhong,Jiao, Ning
supporting information
p. 815 - 818
(2018/07/31)

Heterogeneous Iron-Catalyzed Hydrogenation of Nitroarenes under Water-Gas Shift Reaction Conditions
Reduction of various nitroarenes in the presence of heterogeneous iron oxide-based catalyst Fe 2 O 3 /NGr@C under water-gas shift reaction (WGSR) conditions has been demonstrated. The catalytic material is prepared in a straightforward manner via deposition/pyrolysis of iron-phenanthroline complex on carbon support. It shows high chemoselectivity towards the reduction of nitroarenes in the presence of other reducible and/or poisoning-capable functional groups. Hydrogenation is achieved using CO/H 2 O as a hydrogen source. Furthermore, it is demonstrated that the presence of triethylamine additive has a significant positive effect on the rate of reduction.
Ryabchuk, Pavel,Junge, Kathrin,Beller, Matthias
supporting information
p. 4369 - 4376
(2018/11/21)

Palladium(II)/N-Heterocyclic Carbene-Catalyzed Regioselective Heteroannulation of Tertiary Propargyl Alcohols and o-Haloanilines to form 2-Alkenylindoles
Monometallic and bimetallic palladium(II)/N-heterocyclic carbene complexes appended with naphthalimide or bisnaphthalimide moieties were designed, synthesized, and characterized. Employment of these catalysts brings about the step-economic and regioselective heteroannulation of tertiary propargyl alcohols with o-haloanilines resulting in biologically and pharmaceutically relevant 2-alkenylindoles. Basis for the regioselective heteroannulation is unraveled by coordination of the propargylic hydroxy moiety to palladium during insertion. Embracing this methodology, a single regioisomer of unsymmetrical 2,3-disubstituted indoles could be achieved through late-stage modification. The role of the naphthalimide or bisnaphthalimide appended to the NHC on the catalytic efficiency has been studied. (Figure presented.).
Panyam, Pradeep Kumar Reddy,Gandhi, Thirumanavelan
supporting information
p. 1144 - 1151
(2017/04/13)

A quick, mild and efficient bromination using a CFBSA/KBr system
Bromination is a fundamental transformation in organic chemistry and brominated compounds as building blocks are of paramount importance in organic synthesis. In our study, we have developed an efficient method of bromination by using a CFBSA/KBr system at room temperature in a short reaction time. Notably, this approach has been proven to be applicable to a range of substrates including 1,3-diketones and β-keto esters, phenols, aromatic amines and heteroarenes with good to excellent yields.
Jiang, Pan-Pan,Yang, Xian-Jin
p. 90031 - 90034
(2016/10/09)

Direct Tryptophols Synthesis from 2-Vinylanilines and Alkynes via C - C Triple Bond Cleavage and Dioxygen Activation
An unexpected metal-free C - C triple bond cleavage, dioxygen activation, and reassembly into tryptophol derivatives has been developed. This chemistry provides a novel, simple, and efficient approach to highly valuable tryptophol derivatives from simple substrates under mild conditions. The mechanistic studies may promote the discovery of new methodologies through C-C bond cleavage and dioxygen activation.
Shen, Tao,Zhang, Yiqun,Liang, Yu-Feng,Jiao, Ning
supporting information
p. 13147 - 13150
(2016/10/24)

Preparation method of scandium diboride
The invention discloses a preparation method of scandium diboride, and relates to the chemical industry technical field; p-methylacetanilide is obtained through acetylation and bromization, then is used as a raw material and is subjected to an acidification reaction to obtain hydrochloride, then the hydrochloride as a raw material is subjected to a neutralization reaction to obtain scandium diboride. The preparation method has the beneficial effects of convenient and simple preparation, environmental protection, no pollution, easy available raw materials, low equipment investment, high purity and convenient operation, and the obtained product is good in using effect, and is safe and reliable.
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(2016/12/01)

Palladium-Catalyzed Carbamate-Directed Regioselective Halogenation: A Route to Halogenated Anilines
This study describes an efficient method for ortho-selective halogenation of N-arylcarbamates under mild conditions for the first time. Although being weakly coordinating, N-arylcarbamates act very well as a removable directing group for activation of C-H bonds. The developed procedure results in extremely valuable halogenated N-arylcarbmates that can further be hydrolyzed to halogenated anilines. The obtained reaction conditions showed broad scope and wide functional group tolerance. All the products were formed in good yields with extremely high selectivity.
Moghaddam, Firouz Matloubi,Tavakoli, Ghazal,Saeednia, Borna,Langer, Peter,Jafari, Behzad
p. 3868 - 3876
(2016/05/24)

A facile palladium-catalyzed route to 2,5,7-trisubstituted indoles
A facile and general approach to the synthesis of 2,5,7-trisubstituted indoles from readily available 2-bromo-6-iodo-4-substituted and 2-bromo-4-chloro-6-iodoanilines is reported. The assembly of the indole rings is accomplished via a one-pot Sonogashira cross-coupling with terminal alkynes followed by a palladium-catalyzed cyclization step. The functionalization at C7 and at C5 (with indoles bearing a chloro substituent at C5) is carried out by alkynylations, Suzuki-Miyaura cross-couplings, and Buchwald-Hartwig C-N bond forming reactions. One-pot protocols for the synthesis of 2,5,7-trisubstituted indoles from 2-aryl-7-bromo-5-chloroindoles as well as from 2-bromo-4-chloro-6-iodoaniline are also described.
Cacchi, Sandro,Fabrizi, Giancarlo,Goggiamani, Antonella,Iazzetti, Antonia,Verdiglione, Rosanna
p. 9346 - 9356
(2015/11/27)

Transition-metal-free access to primary anilines from boronic acids and a common +NH2 equivalent
Diversely substituted anilines are prepared by treatment of functionalized arylboronic acids with a common, inexpensive source of electrophilic nitrogen (H2N-OSO3H, HSA) under basic aqueous conditions. Electron-rich substrates are found to be the most reactive by this method. However, even moderately electron-poor substrates are well tolerated under the room temperature conditions. Sterically hindered substrates appear to be equally effective compared to unhindered ones. Highly electron-deficient substrates afford product in very low yields at room temperature, but moderate to good yields are obtained at refluxing temperatures. Our method is also amenable to electrophilic amination of several common boronic acid derivatives (e.g., pinacol esters). We demonstrate that it can be combined with metal-halogen exchange reactions or a variety of directed ortho metalation protocols in a "one-pot" sequence for the synthesis of aromatic amines with unique substitution patterns. DFT studies, in combination with experimental results, suggest that the reaction occurs via base-mediated activation of HSA, followed by 1,2 aryl B-N migration. This mode of activation appears to be critical for the success of the reaction and allows, for the first time, a general, electrophilic amination of boronic acids at ambient temperature.
Voth, Samantha,Hollett, Joshua W.,Mccubbin, J. Adam
p. 2545 - 2553
(2015/03/18)

Preparation of carbazole and dibenzofuran derivatives by selective bromination on aromatic rings or benzylic groups with N-bromosuccinimide
N-Bromosuccinimide (NBS), a bromine source, has been used to study the bromination of toluidine and cresols systematically to clarify the underlying mechanism and the orientation effect. It has been found that bromination of toluidine and cresols which possess electron-donating NH2/OH with NBS gives electrophilic aromatic substitution products quickly instead of the desired benzylic bromination products. In contrast, when the electronic effect of the substituted groups is reversed, only the benzylic bromination products are gained. Based on this methodology, several potential AChE inhibitors, such as 2-methoxy-5-(benzylamino)methyl-dibenzofuran, 3-bromo-2-methoxy-5-methyl-9H- carbazole, 3,6-dibromo-2-methoxy-5-methyl-9H-carbazole, and 5-(bromomethyl)-2- methoxy-9H-(phenylsulfonyl)-carbazole have been synthesized.
Fang, Lei,Zhang, Haun,Fang, Xubin,Gou, Shaohua,Cheng, Lin
p. 635 - 641
(2014/06/23)

Selective bromination of pyrrole derivatives, carbazole and aromatic amines with DMSO/HBr under mild conditions
Bromination of pyrrole derivatives, carbazole and aromatic amines using the DMSO/HBr system affords high yields of the corresponding bromo compounds. Temperature control used in the bromination of anilines helped to promote selective formation of mono- or di-brominated products. Simple operation, low toxicity and high selectivity make this a promising new procedure for the bromination of aromatic compounds.
Liu, Cong,Dai, Rongji,Yao, Guowei,Deng, Yulin
p. 593 - 596
(2015/01/09)

Synthesis of 6-carboxylated phenanthridines by oxidative alkoxycarbonylation-cyclization of 2-isocyanobiphenyls with carbazates
An iron-catalyzed synthesis of 6-carboxylated phenanthridines starting with readily prepared isocyanides and carbazates was developed. Reactions occurred via addition of alkoxycarbonyl radicals to the isocyanide group and subsequent intramolecular cyclization.
Wang, Gao,Chen, Shan-Yong,Yu, Xiao-Qi
supporting information
p. 5338 - 5341
(2015/01/09)

New nickel(II) diimine complexes bearing phenyl and sec-phenethyl groups: Synthesis, characterization and ethylene polymerization behaviour
A series of nickel(II) catalysts containing phenyl and chiral sec-phenethyl groups, {[(4-R1-2-R2C6H2-Rfnet C)2Nap]NiBr2} (Nap: 1,8-naphthdiyl, R1=Me, R2=Ph (3a); R1=Me, R2=sec-phenethyl (3b); R1=Cl, R2=sec-phenethyl (3c); R1=Me, R 2=Me (3d) were synthesized and characterized. All organic compounds were fully characterized by FT-IR and NMR spectroscopy and elemental analysis. The single crystal for X-ray crystallography was isolated from 3a in CH 2Cl2/n-hexane under air; the crystal structure showed a binuclear complex 3a, in which each nickel atom was six-coordinate. The two nickel atoms together with two bromine atoms form a planar four-membered ring, with a bromine and H2O axial ligands. These complexes, activated by diethylaluminum chloride and chiral nickel pre-catalysts rac-3c, exhibited good activities (up to 2.85×106g PE (mol Ni h bar)-1) for ethylene polymerization, and produced polyethylene products with a high degree of branching (up to 117 branched per 1000 carbons) at high temperature. The type and amount of branches of the polyethylenes obtained were determined by 1H and 13C NMR spectroscopy. Copyright
Wang, Fuzhou,Yuan, Jianchao,Li, Qingshan,Tanaka, Ryo,Nakayama, Yuushou,Shiono, Takeshi
p. 477 - 483
(2014/07/07)

Catalytic dehydrogenative borylation of terminal alkynes by a SiNN pincer complex of iridium
Compounds with carbon-boron bonds are versatile intermediates for building more complex molecules via the elaboration of the carbon-boron bonds into other carbon-element bonds. The synthesis of carbon-boron bonds by catalytic dehydrogenative borylation of carbon-hydrogen bonds with dialkoxyboranes (RO)2BH is particularly attractive. It has been demonstrated for a variety of carbon-hydrogen bond types but not for the C(sp)-H bonds of terminal alkynes, for which hydroboration of the triple bond is a competing process. We report a new iridium catalyst that is strictly chemoselective for C-H borylation of terminal alkynes. The key to the success of this catalyst appears to be the new ancillary SiNN pincer ligand that combines amido, quinoline, and silyl donors and gives rise to structurally unusual Ir complexes. A variety of terminal alkynes (RC≡C-H) can be converted to their alkynylboronates (RC≡C-Bpin, where pin = pinacolate) in high yield and purity within minutes at ambient temperature.
Lee, Chun-I,Zhou, Jia,Ozerov, Oleg V.
supporting information
p. 3560 - 3566
(2013/04/23)

Polymer-anchored Cu(II) complex as an efficient catalyst for selective and mild oxidation of sulfides and oxidative bromination reaction
A new polymer-anchored Cu(II) complex has been tested for the oxidation of sulfides and in oxidative bromination reaction with hydrogen peroxide as oxidant. Sulfides have been selectively oxidized to corresponding sulfoxides in excellent yields and in presence of KBr as bromine source, organic substrates have been selectively converted to mono bromo substituted compounds. The polymer-anchored Cu(II) catalyst could be easily recovered by simple filtration and reused more than six times without appreciable loss of its initial activity. Graphical Abstract: [Figure not available: see fulltext.]
Islam, Sk. M.,Roy, Anupam Singha,Mondal, Paramita,Salam, Noor,Paul, Sumantra
p. 225 - 233
(2013/03/13)

Novel synthesis and antimicrobial activity of 3-substituted 5-bromo-7-methyl-1,2,4-triazolo-[3,4-b]-benzothiazoles
4-Methyl acetanilide (1) on treatment with bromine in acetic acid, followed by hydrolysis with dilute HCl/NaOH solution, yielded 2-bromo-4-methyl aniline (2), which on treatment with sodium thiocyanate in acetic acid afforded 2-amino-4-bromo-6-methyl benzothiazole (3). Compound 3 in ethylene glycol was heated at 150°C with 80% hydrazine hydrate to get 4-bromo-2-hydrazino-6- methyl benzothiazole (4). This hydrazino compound 4 on heating with formic acid for 3 h yielded 4-bromo-2-hydrazinoformyl-6-methyl benzothiazole (5). Same compound 4 when heated independently with formic acid for 6 h/urea for 3 h/carbon disulfide in alkali afforded 5-bromo-7-methyl (6)/5-bromo-3-hydroxy-7- methyl (7)/5-bromo-3-mercapto-7-methyl (8)-1,2,4-triazolo-[3,4-b]- benzothiazoles, respectively. Compound 4 on heating with acetic acid/acetic anhydride gave acetyl benzothiazolyl derivative 9, which on cyclization with orthophosphoric acid yielded 5-bromo-3,7-dimethyl-1,2,4-triazolo-[3,4-b]- benzothiazole (10). All these newly synthesized compounds were screened for antimicrobial activity against Escherichia coli (Gram -ve), Bacillus subtilis (Gram +ve), Erwinia carotovora, and Xanthomonas citri using ampicillin, streptomycin, and penicillin as a standard for comparison.
Bhagat,Deshmukh,Kuberkar
p. 873 - 876
(2012/10/30)

A Green protocol for the bromination and iodination of the aromatic compounds using H5IO6/NaBr and H5IO 6/NaI in the water
Bromination and iodination of the aromatic compounds have efficiently been carried out at room temperature and 70 °C, respectively, in short reaction times using orthoperiodic acid/sodium bromide (1:2) and orthoperiodic acid/sodium iodide (1:2) in water to prepare the corresponding halo compounds with excellent yields.
Yousefi-Seyf, Jaber,Tajeian, Kazem,Kolvari, Eskandar,Koukabi, Nadiya,Khazaei, Ardeshir,Zolfigol, Mohammad Ali
p. 2619 - 2622
(2012/10/29)

A facile synthesis of indolo[3,2,1-jk]carbazoles via palladium-catalyzed intramolecular cyclization
A new efficient synthesis of indolo[3,2,1-jk]carbazoles by the palladium-catalyzed cyclization of N-(2-bromoaryl)carbazoles is described. The reaction involves intramolecular C-C bond formation, coupled with the cleavage of a C-X bond and a C-H bond on carbazole ring. Substitutions on N-aryl core with either electron-donating or electron-withdrawing groups are introduced, and different reaction factors for cyclization are evaluated.
Lv, Jun,Liu, Qiancai,Tang, Jie,Perdih, Franc,Kranjc, Kristof
supporting information
p. 5248 - 5252
(2012/10/30)

Design, synthesis, and biological evaluation of novel transrepression- selective liver X receptor (LXR) ligands with 5,11-dihydro-5-methyl-11- methylene-6 H-dibenz[ b, e ]azepin-6-one skeleton
To obtain novel transrepression-selective liver X receptor (LXR) ligands, we adopted a strategy of reducing the transactivational agonistic activity of the 5,11-dihydro-5-methyl-11-methylene-6H-dibenz[b,e]azepin-6-one derivative 10, which exhibits LXR-mediated transrepressional and transactivational activity. Structural modification of 10 based on the reported X-ray crystal structure of the LXR ligand-binding domain led to a series of compounds, of which almost all exhibited transrepressional activity at 1 or 10 μM but showed no transactivational activity even at 30 μM. Among the compounds obtained, 18 and 22 were confirmed to have LXR-dependent transrepressional activity by using peritoneal macrophages from wild-type and LXR-null mice. A newly developed fluorescence polarization assay indicated that they bind directly to LXRα. Next, further structural modification was performed with the guidance of docking simulations with LXRα, focusing on enhancing the binding of the ligands with LXRα through the introduction of substituents or heteroatom(s). Among the compounds synthesized, compound 48, bearing a hydroxyl group, showed potent, selective, and dose-dependent transrepressional activity.
Aoyama, Atsushi,Endo-Umeda, Kaori,Kishida, Kenji,Ohgane, Kenji,Noguchi-Yachide, Tomomi,Aoyama, Hiroshi,Ishikawa, Minoru,Miyachi, Hiroyuki,Makishima, Makoto,Hashimoto, Yuichi
p. 7360 - 7377
(2012/11/07)

Selective oxidation of sulfides and oxidative bromination of organic substrates catalyzed by polymer anchored Cu(II) complex
A new polymer-anchored Cu(II) complex has been synthesized and characterized. The catalytic performance of the complex has been tested for the oxidation of sulfides and in oxidative bromination reaction with hydrogen peroxide as the oxidant. Sulfides have been selectively oxidized to the corresponding sulfoxides in excellent yields and in the presence of KBr as the bromine source, organic substrates have been selectively converted to mono bromo substituted compounds using polymer-anchored Cu(II) catalyst. This catalyst showed excellent catalytic activity, high selectivity, and recyclability. The polymer-anchored Cu(II) catalyst could be easily recovered by filtration and reused more than five times without appreciable loss of its initial activity.
Islam,Roy, Anupam Singha,Mondal, Paramita,Tuhina, Kazi,Mobarak, Manir,Mondal, John
supporting information; experimental part
p. 127 - 131
(2012/01/17)

Synthesis, catalytic oxidation and oxidative bromination reaction of a reusable polymer anchored oxovanadium(IV) complex
Polymer anchored oxovanadium catalyst was synthesized and characterized. The solid catalyst was characterized by Fourier transform infrared spectroscopy (FT-IR), UV-vis diffuse reflectance spectroscopy (DRS), thermogravimetric analysis (TGA) and scanning electron microscope (SEM). Its catalytic activity was evaluated for the oxidation of various alkenes, sulfides and aromatic alcohols with 30% H2O2 under mild reaction conditions. This catalyst was also effective for the oxidative bromination reaction of organic substrates with 80-100% selectivity of mono substituted products with H2O2/KBr at room temperature. The above reactions require minimum amount of H2O2, short time period and most importantly all the above reactions occur in aqueous medium. The developed catalyst can be facilely recovered and reused six times without significant decrease in activity and selectivity. This result confirms that the polymer anchored complex was not leached during the reaction, suggesting the true heterogeneous nature of the catalyst.
Islam, Sk. Manirul,Roy, Anupam Singha,Mondal, Paramita,Salam, Noor
experimental part
p. 38 - 48
(2012/05/21)

Regioselective and high-yielding bromination of phenols and anilins using N-bromosaccharin and amberlyst-15
A regioselective and facile conversion method for bromination of anilines and phenols using N-bromosaccharine in the presence of a catalytic amount of Amberlyst-15 lead to enhancement of the reaction rate and yielded brominated products in good to excellent yields and short reaction times.
Baharfar,Alinezhad,Azimi,Salehian
experimental part
p. 863 - 865
(2012/04/23)

Selective activation of enantiotopic C(sp3)-hydrogen by means of chiral phosphoric acid: Asymmetric synthesis of tetrahydroquinoline derivatives
Chiral phosphoric acid-catalyzed asymmetric C-H functionalization has been achieved. In this process, enantiotopic C(sp3)-hydrogen is selectively activated by chiral phosphoric acid to afford tetrahydroquinoline derivatives with excellent enantioselectivities (up to 97% ee).
Mori, Keiji,Ehara, Kensuke,Kurihara, Kazuki,Akiyama, Takahiko
supporting information; scheme or table
p. 6166 - 6169
(2011/06/21)

Asymmetric sp3 C-H functionalization via a chiral Br?nsted acid-catalyzed redox reaction for the synthesis of cyclic aminals
An organocatalytic asymmetric tandem 1,5-hydride transfer/ring closing reaction of o-aminobenzoketones with anilines to give cyclic aminals in fairly good diastereo- and enantioselectivities.
He, Yu-Ping,Du, Yu-Liu,Luo, Shi-Wei,Gong, Liu-Zhu
supporting information; scheme or table
p. 7064 - 7066
(2012/01/04)

Silica-supported quinolinium tribromide: A recoverable solid brominating reagent for regioselective monobromination of aromatic amines
Silica-supported quinolinium tribromide was synthesized and found to be an efficient, stable, and recoverable solid brominating reagent for the regioselective monobromination of aromatic amines. This protocol has advantages of high yield, mild condition and simple work-up procedure.
Li, Zheng,Sun, Xiunan,Wang, Lue,Li, Yanbo,Ma, Yuanhong
scheme or table
p. 496 - 501
(2010/08/06)

Efficient, rapid, and regioselective bromination of phenols and anilines with N-bromosaccharin using tungstophosphoric acid as a heterogeneous recyclable catalyst
A simple, efficient, and rapid method for high-yielding regioselective mono bromination of phenols and anilines has been achieved by treatment with N-bromasaccharin in the presence of a catalytic amount of tungstophosphoric acid. Copyright Taylor & Francis Group, LLC.
Alinezhad, Heshmatollah,Tavakkoli, Sahar Mohseni,Salehian, Fatemeh
experimental part
p. 3226 - 3232
(2010/12/24)

A synthetic approach to carbazoles using electrochemically generated hypervalent iodine oxidant
Carbazoles were successfully synthesized by oxidative cyclization of the corresponding diaryl derivatives using electrochemically generated hypervalent iodine oxidant. Electron-withdrawing nitro and donating methoxy groups at the para position of the acetamide group interfered with cyclization. Glycozoline (8) was successfully synthesized in five steps with 50% overall yield.
Kajiyama, Daichi,Inoue, Keisuke,Ishikawa, Yuichi,Nishiyama, Shigeru
scheme or table
p. 9779 - 9784
(2011/03/17)

Efficient and regioselective bromination of aromatic compounds with ethylenebis(N-methylimidazolium) ditribromide (EBMIDTB)
A regioselective and highly efficient method for bromination of phenol and aniline derivatives using ethylenebis(N-methylimidazolium) ditribromide (EBMIDTB) as an efficient reagent in dichloromethane at ambient temperature is reported. The reagent can be recovered and reused several times.
Hosseinzadeh, Rahman,Tajbakhsh, Mahmood,Mohadjerani, Maryam,Lasemi, Zahra
experimental part
p. 868 - 876
(2010/05/18)

Simple catalyst-free regio- and chemoselective monobromination of aromatics using NBS in polyethylene glycol
NBS in polyethylene glycol has been efficiently utilized for regio- and chemoselective bromination of activated aromatics at room temperature to form the corresponding bromo products in excellent yields. Copyright Taylor & Francis Group, LLC.
Venkateswarlu, Katta,Suneel, Kanaparthy,Das, Biswanath,Reddy, Kuravallapalli Nagabhushana,Reddy, Thummala Sreenivasulu
experimental part
p. 215 - 219
(2009/04/07)

Effect of structural factors and solvent nature in bromination of anilines
Reaction of electrophilic bromination of aniline containing various ortho, meta, and para substituents in the aromatic ring was studied. The optimal conditions for synthesis of mono-, di-, tri-, and tetrabromo derivatives of aniline and brominated analog of Aniline Black were found.
Bagmanov
experimental part
p. 1570 - 1576
(2011/06/20)

Vilsmeier-haack bromination of aromatic compounds with KBr and N-bromosuccinimide under solvent-free conditions
Bromination of aromatic hydrocarbons is triggered by Vilsmeier-Haack reagent [N,N-dimethyl formamide (DMF-POCl3 system)] in the presence of KBr or N-bromosuccinimide (NBS) under solvent-free conditions by grinding the reactants in a mortar with a pestle. The reactions afforded corresponding bromo derivatives in very good yield with high regioselectivity. The results are comparable with those obtained under reflux conditions. Copyright Taylor & Francis Group, LLC.
Chakradhar,Roopa,Rajanna,Saiprakash
experimental part
p. 1817 - 1824
(2009/10/02)

Ecofriendly solvent free microwave enhanced alkyl migration in N-alkyl anilines in dry media conditions
A rapid, cleaner, cost effective and ecofriendly synthesis of exclusive para alkyl anilines in solvent free conditions using solid supports under microwave irradiation is achieved.
Selvakumar,Easwaramurthy,Raju
p. 713 - 715
(2008/09/18)

An efficient, rapid and regioselective nuclear bromination of aromatics and heteroaromatics with NBS using sulfonic-acid-functionalized silica as a heterogeneous recyclable catalyst
A simple, efficient and rapid method has been developed for high-yielding regioselective nuclear monobromination of aromatic and heteroaromatic compounds using NBS in the presence of sulfonic-acid-functionalized silica at room temperature. The catalyst works under heterogeneous conditions and can be recycled.
Das, Biswanath,Venkateswarlu, Katta,Krishnaiah, Maddeboina,Holla, Harish
p. 8693 - 8697
(2007/10/03)

Co2(CO)8 as novel and water-tolerant reagent for the conversion of azides to amines in aqueous media
Azides are readily converted into their corresponding amines using a catalytic amount of Co2(CO)8 under mild conditions. The method is highly chemoselective and compatible with a variety of functionalities such as halides, esters, acids, ethers, nitro, cyano and olefinic double bonds present in the molecule. Copyright
Yadav,Reddy,Satheesh,Raghavender Rao
p. 340 - 341
(2007/10/03)

An intriguing effect of lithium perchlorate dispersed on silica gel in the bromination of aromatic compounds by N-bromosuccinimide
A convenient and efficient procedure for electrophilic aromatic bromination has been developed by mixing of N-bromosuccinimide and an aromatic compound at room temperature on the surface of silica gel mixed with solid anhydrous LiClO4. All of the substrates examined underwent clean electrophilic aromatic bromination in reaction times of a few minutes to afford the corresponding bromoarenes under neutral conditions in excellent yield. In the case of thiophenol, no substitution reaction occurred, and the corresponding disulfide was obtained in excellent yield.
Bagheri, Mojtaba,Azizi, Najmedin,Saidi, Mohammad R.
p. 146 - 149
(2007/10/03)

Novel bromination method for anilines and anisoles using NH 4Br/H2O2 in CH3COOH
A simple, efficient, regioselective, environmentally safe, and economical method for the oxybromination of anilines and anisoles without catalyst is reported. The electrophilic substitution of bromine generated in situ from ammonium bromide as a bromine source and hydrogen peroxide as an oxidant for the first time.
Krishna Mohan,Narender,Srinivasu,Kulkarni,Raghavan
p. 2143 - 2152
(2007/10/03)

[bmim]Br3 as a new reagent for regioselective monobromination of arylamines under solvent-free conditions
Reaction of arylamines with 1-butyl-3-methylimidazolium tribromide ([bmim]Br3) under solvent-free conditions, gave selectively the corresponding monobromination products with excellent, yields.
Le, Zhang-Gao,Chen, Zhen-Chu,Hu, Yi,Zheng, Qin-Guo
p. 2809 - 2812
(2007/10/03)

A new mild regioselective bromination of arylamines
A new efficient regioselective boron-assisted mono bromination methodology for arylamines is described. Our one-pot, three-stage approach (lithiation, boron amide formation and bromination) proved to be highly useful in mildly brominating a variety of arylamines in up to 94% yields.
Zhao, Jingrui,Jia, Xueshun,Zhai, Hongbin
p. 9371 - 9373
(2007/10/03)

A facile reduction of nitroarenes to anilines using FeCl 3·6H2O/indium
Reduction of a variety of nitroaromatic compounds to the corresponding anilines occurs chemoselectively in high yields upon treatment with a new reduction system consisting of FeCl3·6H2O/indium in aqueous methanol.
Yoo, Byung Woo,Choi, Jin Woo,Hwang, Sun Kyun,Kim, Dong Yoon,Baek, Heung Soo,Choi, Kyung Il,Kim, Joong Hyup
p. 2985 - 2988
(2007/10/03)

Regioselective one-pot bromination of aromatic amines
(Matrix Presented) Treatment of aniline with n-butyllithium and then trimethyltin chloride gave the tin amide (PhNH-SnMe3) in situ. Without isolation of the tin amide reaction with bromine and workup with aqueous fluoride ion gave p-bromoaniline in 76% yield, with no dibromoaniline or o-bromoaniline. Application of this sequence to 11 different aromatic amines gave selective bromination in 36-91% yields, without formation of dibromides. This constitutes a good general method for the regioselective bromination of aromatic amines.
Smith, Michael B.,Guo, Lisa,Okeyo, Sherrad,Stenzel, Jason,Yanella, James,LaChapelle, Eric
p. 2321 - 2323
(2007/10/03)

Regioselective catalytic halogenation of aromatic substrates
Regioselective chlorination and bromination of some aromatic substances have been carried out using KCl and KBr in presence of sodium perborate as an oxidant and sodium metavanadate, sodium tungstate, ammonium metavanadate and ammonium molybdate as efficient catalysts. This environmentally friendly catalytic halogenation method gave good yields of products under mild conditions.
Bandgar,Nigal, Neeta J.
p. 3225 - 3229
(2007/10/03)