- Synthesis of fused aromatic [1,3]dioxoles from 2-hydroxymethylphenols
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The rearrangement of spiroepoxycyclohexadienones to benzo[1,3]dioxoles is best carred out in a non polar solvent (toluene, CCl4) in presence of TBDMSCl. Application to the synthesis of naphthalene and tetrahydronaphthalene derivatives is described.
- Gesson, Jean-Pierre,Mondon, Martine,Pokrovska, Natacha
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Read Online
- Anti-inflammatory, ulcerogenic and platelet activation evaluation of novel 1,4-diaryl-1,2,3-triazole neolignan-celecoxib hybrids
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This study reports the synthesis of novel neolignans-celecoxib hybrids and the evaluation of their biological activity. Analogs 8–13 (L13-L18) exhibited anti-inflammatory activity, inhibited glycoprotein expression (P-selectin) related to platelet activation, and were considered non– ulcerogenic in the animal model, even with the administration of 10 times higher than the dose used in reference therapy. In silico drug-likeness showed that the analogs are compliant with Lipinski's rule of five. A molecular docking study showed that the hybrids 8–13 (L13-L18) fitted similarly with celecoxib in the COX-2 active site. According to this data, it is possible to infer that extra hydrophobic interactions and the hydrogen interactions with the triazole core may improve the selectivity towards the COX-2 active site. Furthermore, the molecular docking study with P-selectin showed the binding affinity of the analogs in the active site, performing important interactions with amino acid residues such as Tyr 48. Whereas the P-selectin is a promising target to the design of new anti-inflammatory drugs with antithrombotic properties, a distinct butterfly-like structure of 1,4-diaryl-1,2,3-triazole neolignan-celecoxib hybrids synthesized in this work may be a safer alternative to the traditional COX-2 inhibitors.
- Baroni, Adriano C. M.,Carvalho, Diego B.,Carvalho, Maria G.,Cassamale, Tatiana B.,Duarte, Rita C. F.,Felipe, Josyelen L.,Louren?o, Leticia D.,Toffoli-Kadri, Monica C.,das Neves, Amarith R.
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- Green bromination method
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The invention discloses a green bromination method, and belongs to the field of green organic chemistry. Under the conditions of room temperature, opening and neutrality, reaction raw materials are aromatic hydrocarbon, olefin, alkyne, tryptamine, tryptophane and derivatives thereof with different functional groups, a bromine source is MBrx (M is Fe , Fe , Ce and the like, and x is 2-3), and the unique oxidant is H2O2. Brominated alkanes, alkenes, aromatic hydrocarbons, pyrrolo-indolines and furo-indolines and derivatives thereof can be produced. The bromination reaction is carried out by using easily available and cheap reagents (such as FeBr2, CeB3 and H2O2) in the market and the solvent, and the method has the characteristics of mild reaction conditions, wide substrate application range, simple steps, easiness in operation and no need of separation, is a green, environment-friendly and safe bromination reaction method, and has a good application prospect.
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Paragraph 0050-0052
(2021/06/13)
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- Bis-selenonium Cations as Bidentate Chalcogen Bond Donors in Catalysis
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Lewis acids are frequently employed in catalysis but they often suffer from high moisture sensitivity. In many reactions, catalysts are deactivated because of the problem that strong Lewis acids also bond to the products. In this research, hydrolytically stable bidentate Lewis acid catalysts derived from selenonium dicationic centers have been developed. The bis-selenonium catalysts are employed in the activation of imine and carbonyl groups in various transformations with good yields and selectivity. Lewis acidity of the bis-selenonium salts was found to be stronger than that of the monoselenonium systems, attributed to the synergistic effect of the two cationic selenonium centers. In addition, the bis-selenonium catalysts are not inhibited by strong bases or moisture.
- He, Xinxin,Wang, Xinyan,Tse, Ying-Lung Steve,Ke, Zhihai,Yeung, Ying-Yeung
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p. 12632 - 12642
(2021/10/21)
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- Evaluation of a Continuous-Flow Photo-Bromination Using N -Bromosuccinimide for Use in Chemical Manufacture
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A continuous-flow photo-bromination reaction on benzyl and phenyl groups was conducted using N-bromosuccinimide as the bromine source inside a preparatory-scale glass plate reactor. This flow reactor system was capable of independently controlling light intensity, wavelength, and reaction temperature, hence exerting an exceptional level of control over the reaction. A short optimisation study for the synthesis of 2-bromomethyl-4-trifluoromethoxyphenylboronic acid pinacol ester resulted in best conditions of 20°C and 10 min residence time using an LED (light-emitting diode) array at 405 nm and acetonitrile as the solvent. The present study evaluates the potential for this easy-to-handle bromination system to be scaled up for chemical manufacture inside a continuous-flow glass plate reactor. The combination with an in-line continuous flow liquid-liquid extraction and separation system, using a membrane separator, demonstrates the potential for continuous flow reaction with purification in an integrated multi-stage operation with minimal manual handling in between.
- Waterford, Matthew,Saubern, Simon,Hornung, Christian H.
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p. 569 - 573
(2021/04/16)
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- Hydrogen-Bond-Donor Solvents Enable Catalyst-Free (Radio)-Halogenation and Deuteration of Organoborons
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A hydrogen bond donor solvent assisted (radio)halogenation and deuteration of organoborons has been developed. The reactions exhibited high functional group tolerance and needed only an ambient atmosphere. Most importantly, compared to literature methods, our conditions are more consistent with the principals of green chemistry (e.g., metal-free, strong oxidant-free, more straightforward conditions).
- Yang, Yi,Gao, Xinyan,Zeng, Xiaojun,Han, Junbin,Xu, Bo
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supporting information
p. 1297 - 1300
(2020/12/23)
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- Design of twisted conjugated molecular systems towards stable multi-colored electrochromic polymers
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Promising advancement of conjugated polymers in electrochromic devices require to design high-performance electrochromic polymers with rich color conversion and long-term stability under cyclic electrical loads. Here we report a new strategy in developing multi-colored electrochromic polymers with good stability via twisted conjugated molecular engineering. A series of twisted hybrid precursors are synthesized by coupling ortho-alkylenedioxybenzenes with EDOT units, and their corresponding polymers are facilely electrosynthesized at relatively low polymerization potentials. The structure-property relationships of such ortho-alkylenedioxybenzene-EDOT hybrid precursors and polymers are systematically elucidated via DFT calculations, spectral, morphological, electrochemical and spectroelectrochemical analysis, etc. We demonstrate that the dihedral angle between ortho-alkylenedioxybenzenes and EDOT moieties can substantially affect the electrochemical and electrochromic properties of polymers. As the dihedral angle and electron cloud density increases, these hybrid polymers display distinct multiple color switching nature and good overall performance including high coloration efficiency (>200 cm2 C?1), decent optical contrast (>45percent), fast switching (1 s), and excellent switching stability (96percent of optical contrast after 3500 cycling) under cyclic electrical loads. With these findings, this work will provide novel insights for rational design of stable and highly efficient multi-colored electrochromic polymers.
- Gu, Hua,Hu, Faqi,Jian, Nannan,Lin, Kaiwen,Liu, Ximei,Lu, Baoyang,Wu, Tao,Xu, Jingkun,Xue, Yu
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- Design, synthesis and antitrypanosomatid activities of 3,5-diaryl-isoxazole analogues based on neolignans veraguensin, grandisin and machilin G
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Using bioisosterism as a medicinal chemistry tool, 16 3,5-diaryl-isoxazole analogues of the tetrahydrofuran neolignans veraguensin, grandisin and machilin G were synthesized via 1,3-dipolar cycloaddition reactions, with yields from 43% to 90%. Antitrypanosomatid activities were evaluated against Trypanosoma cruzi, Leishmania (L.) amazonensis and Leishmania (V.) braziliensis. All compounds were selective for the Leishmania genus and inactive against T.?cruzi. Isoxazole analogues showed a standard activity on both promastigotes of L.?amazonensis and L.?braziliensis. The most active compounds were 15, 16 and 19 with IC50 values of 2.0, 3.3 and 9.5?μM against L.?amazonensis and IC50 values of 1.2, 2.1 and 6.4?μM on L.?braziliensis, respectively. All compounds were noncytotoxic, showing lower cytotoxicity (>250?μM) than pentamidine (78.9?μM). Regarding the structure–activity relationship (SAR), the methylenedioxy group was essential to antileishmanial activity against promastigotes. Replacement of the tetrahydrofuran nucleus by an isoxazole core improved the antileishmanial activity.
- Trefzger, Ozildéia S.,das Neves, Amarith R.,Barbosa, Natália V.,Carvalho, Diego B.,Pereira, Indiara C.,Perdomo, Renata T.,Matos, Maria F. C.,Yoshida, Nidia C.,Kato, Massuo J.,de Albuquerque, Sérgio,Arruda, Carla C. P.,Baroni, Adriano C. M.
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p. 313 - 324
(2018/11/30)
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- Applications of Selenonium Cations as Lewis Acids in Organocatalytic Reactions
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The use of trisubstituted selenonium salts as organic Lewis acids in electrophilic halogenation and aldol-type reactions has been developed. The substrate scope is broad. The reaction conditions are mild and compatible with various functionalities. This study opens a new avenue for the development of nonmetallic Lewis acid catalysis.
- He, Xinxin,Wang, Xinyan,Tse, Ying-Lung (Steve),Ke, Zhihai,Yeung, Ying-Yeung
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supporting information
p. 12869 - 12873
(2018/09/14)
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- Environmentally benign indole-catalyzed position-selective halogenation of thioarenes and other aromatics
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Halogenated aromatic compounds are the cores of many pharmaceutical, agricultural and chemical products but they are commonly prepared using electrophilic halogenation reactions in non-green chlorinated solvents under harsh conditions. A separate problem happens in the aromatic halogenation of thioarenes because they readily undergo oxidative side-reactions. Herein we report an environmentally benign electrophilic bromination of aromatics using an indole-catalytic protocol, which is suitable for a wide range of substrates including thioarenes.
- Shi, Yao,Ke, Zhihai,Yeung, Ying-Yeung
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supporting information
p. 4448 - 4452
(2018/10/17)
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- Zwitterionic-Salt-Catalyzed Site-Selective Monobromination of Arenes
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A zwitterionic-salt-catalyzed electrophilic monobromination of arenes with high regioselectivity has been developed. Under mild reaction conditions, a wide range of monobrominated aromatic compounds can be obtained in excellent yields. The reaction can be operated using an extremely low catalyst loading (0.05 mol %) with the inexpensive brominating agent N-bromosuccinimide. The versatility of this catalytic protocol has been demonstrated by the scale-up reaction with a 0.01 mol % catalyst loading to provide the selectively halogenated compound in quantitative yield.
- Xiong, Xiaodong,Tan, Fei,Yeung, Ying-Yeung
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supporting information
p. 4243 - 4246
(2017/08/23)
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- Palladium-catalysed atom-economical synthesis of conjugated dienals from terminal acetylenes and acrolein
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Conjugated (E,E)-dienals are versatile synthetic intermediates owing to their trifunctional, electrophilic nature and the prevalence of the (E,E)-diene in a wide range of functional molecules. It is shown herein that (E,E)-dienals can be readily prepared
- Hearne, Zo?,Li, Chao-Jun
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supporting information
p. 6136 - 6139
(2017/07/10)
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- Rapid Access to Benzofuran-Based Natural Products through a Concise Synthetic Strategy
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A concise strategy is described for the synthesis of ailanthoidol (1), egonol (2), homoegonol (3), demethoxyegonol (4), demethoxyhomoegonol (5), and stemofuran A (6). This approach involves a Pd-catalysed domino cyclization/coupling process using triarylbismuth reagents for the generation of the benzofuran core. Subsequent structural modifications then give the final targets. The high yielding synthesis of the recently isolated natural products egonol-9(Z)-12(Z)-linoleate (2a), 7-demethoxyegonol-9(Z)-12(Z)-linoleate (4a), and 7-demethoxy-egonol-9(Z)-oleate (4b) are also reported.
- Rao, Maddali L. N.,Murty, Venneti N.
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p. 2177 - 2186
(2016/05/09)
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- Antileishmanial activity and structure-activity relationship of triazolic compounds derived from the neolignans grandisin, veraguensin, and machilin G
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Sixteen 1,4-diaryl-1,2,3-triazole compounds 4-19 derived from the tetrahydrofuran neolignans veraguensin 1, grandisin 2, and machilin G 3 were tested against Leishmania (Leishmania) amazonensis intracellular amastigotes. Triazole compounds 4-19 were synthetized via Click Chemistry strategy by 1,3-dipolar cycloaddition between terminal acetylenes and aryl azides containing methoxy and methylenedioxy groups as substituents. Our results suggest that most derivatives were active against intracellular amastigotes, with IC50 values ranging from 4.4 to 32.7 μM. The index of molecular hydrophobicity (ClogP) ranged from 2.8 to 3.4, reflecting a lipophilicity/hydrosolubility rate suitable for transport across membranes, which may have resulted in the potent antileishmanial activity observed. Regarding structure-activity relationship (SAR), compounds 14 and 19, containing a trimethoxy group, were the most active (IC50 values of 5.6 and 4.4 μM, respectively), with low cytotoxicity on mammalian cells (SI = 14.1 and 10.6). These compounds induced nitric oxide production by the host macrophage cells, which could be suggested as the mechanism involved in the intracellular killing of parasites. These results would be useful for the planning of new derivatives with higher antileishmanial activities.
- Costa, Eduarda C.,Cassamale, Tatiana B.,Carvalho, Diego B.,Bosquiroli, Lauriane S. S.,Ojeda, Mariáh,Ximenes, Thalita V.,Matos, Maria F. C.,Kadri, M?nica C. T.,Baroni, Adriano C. M.,Arruda, Carla C. P.
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- Synthesis and Antitrypanosomastid Activity of 1,4-Diaryl-1,2,3-triazole Analogues of Neolignans Veraguensin, Grandisin and Machilin G
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Sixteen 1,4-diaryl-1,2,3-triazole compounds derived from the natural products veraguensin, grandisin and machilin G were synthesized, with yields of 78-92percent. Biological activity tests against Leishmania amazonensis promastigotes showed that three of these compounds were the most active, with maximum inhibitory concentration (IC50 ) values of 1.1, 3.71 and 7.23 μM. One compound was highly active against Leishmania infantum, with an IC50 value of 5.2 μM, and one derivative showed an IC50 value of 28.6 μM against Trypanosoma cruzi trypomastigotes. Regarding structureactivity relationship (SAR), hybrid 1,2,3-triazolic compounds containing a methylenedioxy group, showed the best antileishmanial and antitrypanosomal activities.
- Cassamale, Tatiana B.,Costa, Eduarda C.,Carvalho, Diego B.,Cassemiro, Nadla S.,Tomazela, Carolina C.,Marques, Maria C. S.,Ojeda, Mariáh,Matos, Maria F. C.,Albuquerque, Sérgio,Arruda, Carla C. P.,Baroni, Adriano C. M.
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p. 1217 - 1228
(2016/08/25)
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- A Metal-Free and Ionic Liquid-Catalyzed Aerobic Oxidative Bromination in Water
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A metal-free aerobic oxidative bromination of aromatic compounds in water has been developed. Hydrobromic acid is used as a bromine source and 2-methylpyridinium nitrate ionic liquid is used as a recyclable catalyst. Water is used as the reaction mediate. This is the first report of aerobic oxidative bromination using only catalytic amount of metal-free catalyst. This system shows not only high bromine atom economy, but also high bromination selectivity. The possible mechanism and the role of the catalyst in this system have also been discussed.
- Wang, Jian,Chen, Shu-Bin,Wang, Shu-Guang,Li, Jing-Hua
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p. 513 - 517
(2015/03/30)
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- HETEROCYCLIC COMPOUNDS FOR THE INHIBITION OF PASK
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Disclosed herein are new heterocyclic compounds of Formula IIa: and compositions thereof, and their application as pharmaceuticals for the treatment of disease. Methods of inhibiting PAS Kinase (PASK) activity in a human or animal subject are also provided for the treatment of diseases such as diabetes mellitus.
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Paragraph 0309; 0310
(2014/05/20)
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- Practical and metal-free electrophilic aromatic halogenation by interhalogen compounds generated in situ from N-halosuccinimide and catalytic TMSCL
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Halomonochloride compounds (ClCl, BrCl, ICl) generated in situ from N-halosuccinimide and catalytic chlorotrimethylsilane (TMSCl, 0.1 equiv) can efficiently halogenate aromatic compounds to give halogenated products in good to excellent yields and selectivities. The reaction can be carried out at room temperature or at lower temperatures, requires only one hour, is practical to apply to a wide range of substrates, and provides a simple access to a variety of haloarene compounds. Georg Thieme Verlag Stuttgart New York.
- Maibunkaew, Tapanee,Thongsornkleeb, Charnsak,Tummatorn, Jumreang,Bunrit, Anon,Ruchirawat, Somsak
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supporting information
p. 1769 - 1775
(2014/08/05)
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- In situ acidic carbon dioxide/water system for selective oxybromination of electron-rich aromatics catalyzed by copper bromide
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Carbon dioxide, being one of the major greenhouse gases responsible for global warming, its atmospheric level grows ever faster since the beginning of industrial era. Great efforts have been devoted to developing versatile technologies/processes to adjust and manipulate the rapid growth of CO 2 emission. Besides CO2 capture and storage/sequestration (CCS) to control its emission, chemical utilization of the captured CO 2 (CCU) emerges to be a rational technique for economical benefits as well as environmental concerns. As for the aim of CO2 utilization, an environmentally benign CO2/water reversible acidic system was developed for the copper (II)-catalyzed selective oxybromination of electron-rich aromatics without the need of any conventional acid additive and organic solvent. Notably, up to 95% yields of the bromination products were attained with good regio-selectivity when cupric bromide was used as the catalyst and lithium bromide as a cheap and easy handling bromine source under supercritical CO2. The catalytic system worked well for electron-rich aromatics including ethers, sulfides and mesitylene. Carbonic acid in situ formed from CO2 and water is supposed to act as the proton donator in the Bronsted acid-promoted reaction. Notably, CO2 in this study serves as a reaction medium and a promoter in conjunction with water and also provides safe environment for aerobic reactions. Given with excellent reaction efficiency as well as no need of neutralization disposal, this process thus represents an environmentally friendly approach for aerobic bromination of aromatics with essential reduction of CO2 emission as well as an economically beneficial way for application of captured CO2.
- Liu, An-Hua,Ma, Ran,Zhang, Meng,He, Liang-Nian
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- Ruthenium-catalyzed transformation of aryl and alkenyl triflates to halides
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Aryl triflates were transformed to aryl bromides/iodides simply by treating them with LiBr/NaI and [Cp*Ru(MeCN)3]OTf. The ruthenium complex also catalyzed the transformation of alkenyl sulfonates and phosphates to alkenyl halides under mild conditions. Aryl and alkenyl triflates undergo oxidative addition to a ruthenium(II) complex to form η'1- arylruthenium and 1-ruthenacyclopropene intermediates, respectively, which are transformed to the corresponding halides.
- Imazaki, Yusuke,Shirakawa, Eiji,Ueno, Ryota,Hayashi, Tamio
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supporting information
p. 14760 - 14763
(2012/11/07)
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- In situ acidic carbon dioxide/ethanol system for selective oxybromination of aromatic ethers catalyzed by copper chloride
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An environmentally benign carbon dioxide/ethanol reversible acidic system was developed for the copper(II)-catalyzed regioselective oxybromination of aromatic ethers without the need of any conventional acid additive and organic solvent. Good to excellent yields together with very good regioselectivity were achieved when easily available cupric chloride dihydrate was used as catalyst and lithium bromide as the cheap and easy-to-handle bromine source under supercritical carbon dioxide conditions. Notably, the catalytic system worked well for a wide range of aromatic ethers including sulfides, resulting in the formation of the mono-brominated products in high yields and exclusive regioselectivity. The alkylcarbonic acid in situ formed from ethanol and carbon dioxide is assumed to play the crucial role in the Braonsted acid-promoted reaction, which could probably act as the proton donator, and was studied employing in situ FT-IR technique under carbon dioxide pressure by monitoring the vibration shift of the hydroxy group of ethanol. Given with excellent bromine atom efficiency as well as no need of neutralization in waste disposal, this approach thus represents a greener pathway for the aerobic bromination of aromatic ethers. A possible catalytic cycle for the in situ alkylcarbonic acid-assisted oxybomination and the effect of supercritical carbon dioxide, i.e., activation of alcohol and enhancement of mass transfer are also discussed. Copyright
- Liu, An-Hua,He, Liang-Nian,Hua, Fang,Yang, Zhen-Zhen,Huang, Cheng-Bin,Yu, Bing,Li, Bin
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experimental part
p. 3187 - 3195
(2012/01/06)
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- An improved palladium-catalyzed conversion of aryl and vinyl triflates to bromides and chlorides
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A facile Pd-catalyzed conversion of aryl and vinyl triflates to aryl and vinyl halides (bromides and chlorides) is described. This method allows convenient access to a variety of aryl, heteroaryl, and vinyl halides in good to excellent yields and with greatly simplified conditions relative to our previous report.
- Pan, Jun,Wang, Xinyan,Zhang, Yong,Buchwald, Stephen L.
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supporting information; experimental part
p. 4974 - 4976
(2011/11/06)
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- Gold-catalyzed halogenation of aromatics by N-halosuccinimides
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(Chemical Equation Presented) Golden bromination: A highly efficient and mild AuCl3-catalyzed bromination of aromatic rings with Nbromosuccinimide (NBS) has been developed. This method works with a low catalyst loading (down to 0.01 mol %) and can be combined with transition metal catalyzed transformations to deliver various aryl products.
- Mo, Fanyang,Yan, Jerry Mingtao,Qiu, Di,Li, Fei,Zhang, Yan,Wang, Jianbo
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scheme or table
p. 2028 - 2032
(2010/06/17)
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- Synthesis of arylbromides from arenes and Nbromosuccinimide bromosuccinimide (NBS) in acetonitrile - A convenient method for aromatic bromination
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Regioselective and chemoselective electrophilic bromination of a wide series of activated arenes using N-bromosuccinimide (NBS) in acetonitrile occurs readily. Environmentally friendly conditions, large substrate scope, and ease of synthesis enhance the utility of this method over other electrophilic bromination conditions.
- Zysman-Colman, Eli,Arias, Karla,Siegel, Jay S.
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experimental part
p. 440 - 447
(2009/12/01)
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- A new method of bromination of aromatic rings by an iso-amyl nitrite/HBr system
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A mixture of iso-amyl nitrite/HBr is shown to be a mild and efficient reagent for electrophilic aromatic bromination. The reaction succeeds with slightly activated arenes and heterocyclic compounds. By using HCl instead of HBr, chlorination can also be performed in few cases. The i-amONO2/HBr mixture can also be utilized for bromination in the α-position of electron withdrawing groups. A possible mechanism is briefly discussed.
- Gavara, Laurent,Boisse, Thomas,Rigo, Beno?t,Hénichart, Jean-Pierre
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p. 4999 - 5004
(2008/09/21)
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- METHOD FOR PRODUCING 4-HALOCATECHOL COMPOUND
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Disclosed is a method for producing a 4-halocatechol compound, which is characterized in that a catechol compound is reacted with 1,3-dihalo-5,5-dimethylhydantoin. Also disclosed are a high-purity 4-chloromethylenedioxybenzene which is characterized in that the methylenedioxybenzene content is not more than 0.5% by mass and the 4,5-dichloromethylenedioxybenzene content is not more than 0.5% by mass, and a method for producing such a high-purity 4-chloromethylenedioxybenzene.
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Page/Page column 9
(2008/06/13)
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- Columnar and smectic liquid crystals based on crown ethers
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Unsymmetrical benzo[15]-crown-5 ethers 5 with one lateral ortho-terphenyl unit bearing alkoxy side chains of varying chain lengths (C5-C14) were prepared from 3,4-dialkoxyphenylbromides 2. Complexation with metal salts MX (M = Na, Cs) afforded the corresp
- Steinke, Nelli,Frey, Wolfgang,Baro, Angelika,Laschat, Sabine,Drees, Christina,Nimtz, Manfred,Haegele, Constanze,Giesselmann, Frank
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p. 1026 - 1035
(2007/10/03)
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- Sodium nitrite-catalyzed oxybromination of aromatic compounds and aryl ketones with a combination of hydrobromic acid and molecular oxygen under mild conditions
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A novel and efficient catalytic system for the oxybromination of aromatic compounds and aryl ketones utilizing a combination of aqueous hydrobromic acid and molecular oxygen in the presence of sodium nitrite under mild conditions has been developed. The newly developed catalytic system utilizes cheap and readily available reactants, exhibits high bromine atom economy and releases only innocuous water as the by-product.
- Zhang, Guofu,Liu, Renhua,Xu, Qing,Ma, Lixin,Liang, Xinmiao
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p. 862 - 866
(2007/10/03)
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- NOVEL PYRIMIDINE COMPOUNDS, PROCESS FOR THEIR PREPARATION AND COMPOSITIONS CONTAINING THEM
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The present invention provides new heterocyclic compounds, particularly substituted pyrimidines, methods and compositions for making and using these heterocyclic compounds, and methods for treating a variety of diseases and disease states, including atherosclerosis, arthritis, restenosis, diabetic nephropathy, or dyslipidemia, or disease states mediated by the low expression of Perlecan.
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Page/Page column 236-237
(2008/06/13)
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- Efficient halogenation of aromatic systems using N-halosuccinimides in ionic liquids
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A simple, rapid and highly regioselective green protocol has been developed for the halogenation of aromatic systems with N-halosuccinimides using room temperature ionic liquids (ILs) as novel and recyclable reaction media to produce the corresponding halogenated aromatic compounds in high to quantitative yields. N-Halosuccinimides show enhanced reactivity in ionic liquids thereby reducing the reaction times dramatically and improving the yields substantially.
- Yadav,Reddy,Reddy,Basak,Narsaiah
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- Novel bromination method for anilines and anisoles using NH 4Br/H2O2 in CH3COOH
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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
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p. 2143 - 2152
(2007/10/03)
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- (Diacetoxyiodo)benzene-Lithium Bromide as a Convenient Electrophilic Br+ Source
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A mild and versatile procedure for the bromination of olefins and activated arenes by in situ generation of 'Br+' using (diacetoxyiodo)benzene and lithium bromide is presented. The reactions were carried out in open vessels at room temperature and were typically complete in 30 minutes. The brominated products were isolated by column chromatography, which also allowed for the isolation of the iodobenzene by-product for recycle.
- Braddock, D. Christopher,Cansell, Gemma,Hermitage, Stephen A.
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p. 461 - 464
(2007/10/03)
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- An efficient chemo and regioselective oxidative nuclear bromination of activated aromatic compounds using lithium bromide and ceric ammonium nitrate
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A mild, efficient and highly chemo- and regioselective method for the bromination of electron rich aromatic molecules has been developed by electrophilic substitution of Br+, which was generated in situ from LiBr using ceric ammonium nitrate as the oxidant. Free aromatic amines remained unaffected under the reaction conditions.
- Roy, Subhas Chandra,Guin, Chandrani,Rana, Kalyan Kumar,Maiti, Gourhari
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p. 6941 - 6942
(2007/10/03)
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- Application of the β-azidonation reaction to the enantioselective synthesis of the lycorane amaryllidaceae alkaloids
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The prochiral ketone 5 was treated with the lithium salt of (+)-bis(α- methylbenzyl)amine, followed by triisopropylsilyl trifluoromethanesulfonate to give 10 (96%). β-Azidonation of 10 with (PhlO)(n)/TMSN3 rapidly produced 11 (95%) as a mixture
- Magnus,Bailey,Porter
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p. 13927 - 13936
(2007/10/03)
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- Benzopyridazinone and pyridopyridazinone compounds
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Benzo or pyridopyridazinones and pyridazinthiones of the formula STR1 wherein: X and Y are nitrogen or carbon, provided that at least one is carbon, and Z is oxygen or sulfur; R1 is hydrogen, lower alkyl, aryl, aralkyl, heterocyclo, heterocyclo lower-alkyl, heteroaryl, or heteroaralkyl; R2, R3, R4, R5 and R6 are independently selected from hydrogen, lower alkyl, halo, carboxy, alkoxycarbonyl, carbamoyl, lower-alkyl carbonyl, halocarbonyl, thiomethyl, trifluoromethyl, cyano or nitro; or a pharmaceutically acceptable ester, ether or salt thereof, have been found to be useful as an anti-inflammatory, antasthmatic, immunosuppressive, anti-allograft rejection, anti-graft-vs-host rejection, autoimmune disease or analgetic agent(s).
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- Fluorine-containing five-membered ring compounds, and a liquid-crystaline medium containing them
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Fluorine-containing five-membered ring compounds of the formula I in which W is STR1 is a cyclohexane, cyclohexene or phenyl, Y1 is O or S, Y2 is (a) O, S, C=O or fluoroalkyl, Y3 is (a) N, CH or CF, Q is C=O, CHF, CF2
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