- Efficient bifunctional nanocatalysts by simple postgrafting of spatially isolated catalytic groups on mesoporous materials
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(Chemical Equation Presented) Hard graft pays off for Henry: An efficient acid-base bifunctional mesoporous catalyst was prepared by one-step post-synthesis grafting of aminoorganoalkoxysilane groups on mesoporous silica (see picture). The catalyst led to
- Sharma, Krishna K.,Asefa, Tewodros
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Read Online
- Synthesis of functionalized carbon microspheres and their catalyst activity in C—O and C—N bond formation reactions
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Disclosed herein is a simple process for functionalization/grafting of carbon microspheres obtained from bagasse with various active functional groups onto it and use of the same as catalyst for various organic reactions, having very high selectivity and conversion rate.
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Page/Page column 8-9
(2019/02/14)
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- Access to C5-Alkylated Indolines/Indoles via Michael-Type Friedel-Crafts Alkylation Using Aryl-Nitroolefins
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A straightforward synthetic route toward C5-alkylated indolines/indoles has been developed. The strategy is composed of Zn(OTf)2-catalyzed Friedel-Crafts alkylation of N-benzylindolines with nitroolefins, and a series of diverse indolines was first obtained in up to 99% yield. This reaction provides a direct and practical route to a variety of the C5-alkylated indolines which were also utilized for accessing corresponding indoles. Indoline derivatives with free NH groups could be obtained through an N-deprotection reaction. Moreover, the primary alkyl nitro groups in both indolines and indoles are amenable to further synthetic elaborations, thereby broadening the diversity of the products.
- Ertugrul, Berrak,Kilic, Haydar,Lafzi, Farrokh,Saracoglu, Nurullah
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p. 9018 - 9038
(2018/06/27)
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- Zeolite Y-assisted nitration of aromatic and heterocyclic compounds and decarboxylative nitration of α,β-unsaturated acids under non-conventional conditions
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Zeolite Y was found to be an efficient catalyst for a facile nitration of aromatic compounds with acetonitrile as the solvent in the presence of small amounts of HNO3 at room temperature. The reactions afforded mono-nitro derivatives of aromatic compounds in about three hours under stirred conditions with high yields and regioselectivity. The reaction times drastically reduced to about 20 min under sonication and to about 20 s under microwave irradiation. Zeolite is recovered after completion of the reaction and recycled for three to four times without any problem. The approach is particularly appropriate for the conversion of unsaturated cinnamic acids into nitrostyrenes.
- Sudhakar Chary,Rajanna,Krishnaiah,Srinivas
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p. 1430 - 1434
(2016/03/08)
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- METHODS AND COMPOSITIONS FOR SELECTIVE AND TARGETED CANCER THERAPY
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Provided herein are methods and compositions for selective and targeted cancer therapy, in particular certain benzothiophenes, benzothiazoles, oxalamides, N-acyl ureas and chromones, and their use in selectively treating certain adenocarcinomas. In some embodiments, the selective toxicity of the compounds may be mediated through SCD1 and/or CYP450 such as CYP4F11.
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Page/Page column 227
(2015/03/28)
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- Ethylenediamine-functionalized magnetic Fe3O4@SiO2 nanoparticles: cooperative trifunctional catalysis for selective synthesis of nitroalkenes
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A magnetically separable trifunctional nanocatalyst Fe3O4@SiO2-NH2 was synthesized and characterized by TEM, FT-IR, XRD, TGA, and EA. The designed nanocatalyst was found to be highly active for selective synthesis of nitroalkenes with nitromethane and aromatic aldehyde through cooperative trifunctional catalysis of primary amine, secondary amine and Si-OH groups on the surface of the catalyst. Under the optimized conditions, various representative substrates were extended to obtain the corresponding products in moderate or excellent yields. After the reaction, the trifunctional nanocatalyst was easily recovered and recycled by applying an external magnet. In addition, a possible cooperative trifunctional catalysis mechanism was also proposed.
- Xue, Fengjun,Dong, Yahao,Hu, Peibo,Deng, Yanan,Wei, Yuping
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p. 73684 - 73691
(2015/09/15)
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- Ultrasonically Assisted Rate Enhancements in Trichloroisocyanuric Acid/DMF/NaNO2 Triggered Nitration of Aromatic Compounds and Decarboxylative Nitration of α,β-Unsaturated Acids
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An efficient and safe method for nitration of aromatic compounds and decarboxylative nitration of α,β-unsaturated acids was developed using trichloroisocyanuric acid (TCICA)/dimethylformamide (DMF) in the presence of NaNO2. The reaction times of conventional protocol reduced from 8-10 h to 1.0-1.5 h (60-90 min) under sonication, even though the yields are comparable under both the conditions.
- Kumar, Mukka Satish,Rajanna, Kamatala Chinna,Venkateswarlu, Marri,Venkanna, Purugula,Saiprakash, Pondichery Kuppuswamy
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p. 2251 - 2258
(2015/09/22)
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- Ultrasonic and microwave-assisted synthesis of β-nitro styrenes and nitro phenols with tertiary butyl nitrite under acid-free conditions
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Tertiary butyl nitrite (TBN) is an acid-free and safe nitrating agent that provides preferentially β-nitrostyrenes with cinnamic acids and corresponding nitro derivatives with phenols in good yields under classical conditions. However, ultrasonic and microwave-assisted reactions reduced the reaction times substantially and enhanced the yields from good to excellent. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications to view the free supplemental file.
- Kumar, M. Satish,Rajanna,Reddy, K. Rajendar,Venkateswarlu,Venkanna
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supporting information
p. 2672 - 2677
(2013/07/26)
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- Oxalylchloride/DMF as an efficient reagent for nitration of aromatic compounds and nitro decarboxylation of cinnamic acids in presence of KNO 3 or NaNO2 under conventional and nonconventional conditions
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Nitration of aromatic compounds and cinnamic acids with oxalylchloride/DMF afforded the corresponding nitro derivatives in the presence of KNO3 or NaNO2 under conventional and nonconventional (ultrasonic and microwave) conditions. The present methodology offers several benefits such as excellent yields, simple work-up procedure, and short reaction times. The yields obtained under present methodology are comparable with those obtained from (POCl3/DMF/KNO3 or NaNO2) and (SOCl 2/DMF/KNO3 or NaNO2) systems followed by shorter reaction times. The reaction times of sonication and microwave conditions are very shorter than those of the conventional conditions.
- Kumar, M. Satish,Reddy, K. Rajendar,Rajanna,Venkanna,Krishnaiah
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p. 977 - 983
(2013/06/05)
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- Ambiphilic dual activation role of a task-specific ionic liquid: 2-hydroxyethylammonium formate as a recyclable promoter and medium for the green synthesis of β-nitrostyrenes
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A cost-effective task-specific ionic liquid, 2-hydroxyethylammonium formate, efficiently promotes the condensation of nitroalkanes with various aldehydes to produce β-nitrostyrenes in high to excellent yields at room temperature. This reaction does not involve any hazardous organic solvent and toxic catalyst. The ionic liquid is recovered and recycled for subsequent reactions. In addition, a novel mechanism has been proposed invoking ambiphilic dual activation influence of the ionic liquid.
- Alizadeh, Abdolhamid,Khodaei, Mohammad M.,Eshghi, Ali
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scheme or table
p. 8295 - 8298
(2011/03/17)
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- Continuous Henry reaction to a specific product over nanoporous silica-supported amine catalysts on fixed bed reactor
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We report a method for continuously producing the nitroaldol, the nitrostyrene, or the Michael product by performing the Henry reaction over a fixed bed reactor that is packed with primary or secondary amine-functionalized nanoporous materials. The % conv
- Biradar, Ankush V.,Sharma, Krishna K.,Asefa, Tewodros
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experimental part
p. 19 - 26
(2011/08/06)
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- SELECTIVE AND EFFICIENT BIFUNCTIONAL AND TRIFUNCTIONAL NANOPOROUS CATALYSTS
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Selective and efficient multifunctional nanoporous catalysts containing spatially distributed organoamine and silanol groups, and methods of preparation thereof. The catalysts have been observed to be very highly efficient in catalysis of the Henry reaction.
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Page/Page column 24
(2009/03/07)
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- Henry reaction catalyzed by aminopropylated nanosilica
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The Henry reaction was catalyzed by 0.01 equiv of aminopropylated nanosilica particles (nano-NAP) in refiuxing nitroalkanes to provide nitrostyrenes in good yields. The catalyst could be recycled up to three times in 76% average yield. Copyright
- Hagiwara, Hisahiro,Sekifuji, Masayoshi,Tsubokawa, Norio,Hoshi, Takashi,Suzuki, Toshio
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scheme or table
p. 790 - 791
(2010/03/04)
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- Cooperative acid-base effects with functionalized mesoporous silica nanoparticles: Applications in carbon-carbon bond-formation reactions
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Acid-base bifunctional mesoporous silica nanoparticles (MSN) were prepared by a one-step synthesis by co-condensation of tetraethoxysilane (TEOS) and silanes possessing amino and/or sulfonic acid groups. Both the functionality and morphology of the particles can be controlled. The grafted functional groups were characterized by using solid-state 20Si and 13C cross-polarization/magic angle spinning (CP/MAS) NMR spectroscopy, thermal analysis, and elemental analysis, whereas the structural and the morphological features of the materials were evaluated by using XRD and N2 adsorptiondesorption analyses, and SEM imaging. The catalytic activities of the monoand afunctional mesoporous hybrid materials were evaluated in carboncarbon coupling reactions like the nitroaldol reaction and the one-pot de-acetalization-nitroaldol and deacetalization-aldol reactions. Among all the catalysts evaluated, the bifunctional sample containing amine and sulfonic acid groups (MSN-NNH2-SO3H) showed excellent catalytic activity, whereas the homogeneous catalysts were unable to initiate the reaction due to their mutual neutralization in solution. Therefore a cooperative acid-base activation is envisaged for the carboncarbon coupling reactions.
- Shylesh, Sankaranarayanapillai,Wagner, Alex,Seifert, Andreas,Ernst, Stefan,Thiel, Werner R.
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experimental part
p. 7052 - 7062
(2010/03/30)
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- The rapid synthesis of β-nitrostyrenes under microwave irradiation without solvent
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The β-nitrostyrenes (3a-l) were prepared by condensation of benzaldehydes with nitromethane in the presence of K2CO3/Al2O3 under microwave irradiation without solvent. They were characterized by IR, 1H-NMR, and elemental analysis.
- Wang, Cunde,Wang, Song
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p. 3481 - 3486
(2007/10/03)
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- Microwave-induced solvent-free, rapid and efficient synthesis of conjugated nitroalkenes using sulfated zirconia
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Sulfated Zirconia catalyzed synthesis of conjugated nitroalkenes has been carrried out under solvent-free condition using sulfated zirconia. Recyclability of catalyst, isolation of pure products by simple filtration and evaporation are important features of this method.
- Bandgar,Kasture
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p. 1239 - 1241
(2007/10/03)
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- Reaction of Biologically Active &β-Nitrostyrenes with o-Phenylenediamine: A New Route to the Synthesis of 2-Substituted Benzimidazoles
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β-Nitrostyrenes (1) react with o-phenylenediamine in ethanol to give exclusively 2-substituted benzimidazoles (2) regardless of the nature and position of substituents in the phenyl ring.The correspondnig 2,3-dihydroperimidines (4) are readily obtained by reacting 1,8-diaminonaphthalene with benzaldehydes.Possible routes for the formation of 2 have been discussed.The nitrostyrenes (1) have been found to be toxic to fresh water snails and phytopathogenic fungi in high dilutions.
- Latif, N.,Mishriky, N.,Assad, F. M.,Meguid, S. Abdel
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p. 872 - 874
(2007/10/02)
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