- An efficient and selective benzylic oxidation of tetralin to 1-tetralone on Cu(II) immobilized Γ-Fe2O3@SBA-15 magnetic nanocatalyst in green water medium without base or additives
-
A novel Cu(II)/γ-Fe2O3@SBA-15 magnetic nanocatalyst has been synthesized aiming at possessing high surface area, magnetic property, highly dispersed and stabilized Cu(II) complex using SBA-15 by sequential magnetization and Cu(II) immobilization with Fe(acac)3 and Cu(OAc)2 precursors. The nanocatalyst was well authenticated by different techniques like BET surface area, X-ray diffraction, X-ray photoelectron spectroscopy, FT-IR, vibrating sample magnetometer and thermogravimetric analysis. Cu(II)/γ-Fe2O3@SBA-15 was found to be effective for the benzylic oxidation of tetralin to 1-tetralone using TBHP at mild reaction conditions in green water medium even in absence of any bases or additives. The heterogeneity of catalyst was confirmed by hot filtering test and further reused for at least 4 times without significant loss in catalytic activity. Ease of catalyst separation, its reusable capacity, wider applicability of alkyl aromatics and importantly reaction operation in water as green medium by elimination of hazardous organic solvents are the commendable merits of this catalyst.
- Neeli, Chinna Krishna Prasad,Kannapu, Hari Prasad Reddy,Kalevaru, Venkat Narayana,Kamaraju, Seetha Rama Rao,Burri, David Raju
-
-
Read Online
- Torsional Angle and Conformation in 2-Vinylanthracene Studied by NMR Spectroscopy and MO Calculations
-
High-resolution deuterium NMR spectra of 2-vinylanthracene-α-d in dichloromethane were recorded.The observed quadrupolar splitting was used to calculate the torsional angle between the vinyl and anthracene planes.The potential energy surface for rotation about the C(vinyl)-C(arom) bond is calculated by using the AM1 Hamiltonian.
- Ni, Yong,Siegel, Jay S.,Hsu, Victor L.,Kearns, David R.
-
-
Read Online
- Friedel-crafts alkylation and acylation in the absence of solvent
-
A short and efficient synthetic route, for alkylation and acylation of aromatic compounds in the absence of solvent is developed. According to the reaction system and conditions used, different alkyl-, and acyl arenes are obtained in moderate to good yields. The structures are assigned by 1H and 13C NMR spectroscopy.
- Ghiaci,Asghari
-
-
Read Online
- Concerted Interplay of Excimer and Dipole Coupling Governs the Exciton Relaxation Dynamics in Crystalline Anthracenes
-
A combined theoretical and experimental investigation into the role of concerted long- (dipole coupling) and short-range (orbital overlap mediated excimer) electronic interactions in modulating the emission of six crystalline acetylanthracenes (1–3) is reported. Friedel–Crafts acylation of anthracene rendered crystalline acetylanthracenes with discrete close packing, varied orbital overlap, and resultant distinct emission (blue–green–yellow) from cooperative excimer and dipole coupling. Time-resolved emission spectroscopy (TRES) studies and the Kasha's exciton theory based quantitative estimation of dipole coupling (mean-field approximation) substantiates the exciton dynamics in crystalline 1–3. Extension of the Kasha's exciton model beyond the traditional nearest-neighbor approach, and consistent agreement among the computed spectral shifts and TRES temporal components, corroborate a holistic approach to decipher the exciton relaxation dynamics in the molecular assembly of novel photonic materials.
- Philip, Abbey M.,Manikandan, Sreenath K.,Shaji, Anil,Hariharan, Mahesh
-
-
Read Online
- Na-promoted aerobic oxidation of alcohols to ketones
-
Aerobic oxidation of a number of diaryl and arylalkyl carbinols to ketones was promoted by Na in THF at room temperature with up to 99% yield. This new oxidation method is also selective with good efficiency for the oxidation of benzylic secondary alcohols but not for a primary alcohol or nonbenzylic secondary alcohols. Under nitrogen, a catalytic amount of Ni or transition metal halides such as CoCl3, FeCl3, and NiCl3 in combination with Na was also found to conduct a dehydrogenation of a secondary alcohol to the corresponding ketone in high yield at room temperature.
- Zhou, Li-Hong,Yu, Xiao-Qi,Pu, Lin
-
-
Read Online
- Selective benzylic oxidation of alkylaromatics over Cu/SBA-15 catalysts under solvent-free conditions
-
With the purpose of benzylic oxidation of alkylaromatics into corresponding ketones selectively under solvent-free conditions, cheap, simple and versatile Cu/SBA-15 catalyst system with the Cu loading of 5, 10, 15 and 20% has been prepared by impregnating SBA-15 support. Among Cu/SBA-15 catalysts, 10%Cu/SBA-15 exhibited superior activity and selectivity.
- Neeli, Chinna Krishna Prasad,Narani, Anand,Marella, Ravi Kumar,Rama Rao, Kamaraju Seetha,Burri, David Raju
-
-
- Derivative spectrophotometric method for simultaneous determination of nickel(II) and copper(II) using 6-(anthracen-2-yl)-2,3-dihydro-1,2,4-triazine-3- thione
-
Derivative spectrophotometric method using newly synthesized reagent, 6-(anthracen-2-yl)-2,3-dihydro-1,2,4-triazine-3-thione (ADTT), has been developed for the simultaneous determination of copper and nickel. The reagent was synthesized by the acylation of anthracene and then reaction of the resulted product with amylnitrite to produce (anthracen-2-yl)-glyoxal aldoxime. After addition of thiosemicabazone the reagent was prepared. Copper and nickel were determined by using zero-crossing method in the second, third and fourth order derivative spectra after derivatization in basic medium. Beers's law was obeyed in the range of 5-35 μg/mL for copper at 387 nm (second order) and 554 nm (third order) and 5-35 μg/mL nickel at 447 nm (first order), 400 nm (third order) and 385 nm (fourth order). The limit of quantification was 5 μg/mL for both cations. The within-day and between-day variations in three concentrations were less than 3.36 and 4.73 % in all measurements, respectively. The proposed method is simple and accurate for determination of binary mixtures.
- Tehrani, M. Barazandeh,Mirkamali,Souri,Foroumadi
-
experimental part
p. 4517 - 4521
(2012/08/28)
-
- Selective benzylic oxidation of alkyl substituted aromatics to ketones over Ag/SBA-15 catalysts
-
Benzylic and cycloalkane CH bonds have selectively been oxidized into corresponding ketones with t-BuOOH over Ag/SBA-15 catalysts, which were prepared by varying the loading of Ag (2, 4, 6 and 8% by weight) on SBA-15 support using an impregnation method. The retention of mesoporous structural ordering and crystalline behavior of Ag have been confirmed by N2 adsorption and XRD studies. 4Ag/SBA-15 catalyst is found to be the best catalyst among the Ag/SBA-15 series. The influence of various parameters such as oxidant, solvent, temperature and time of reaction etc. have been systematically studied on Ag/SBA-15 catalyst.
- Anand, Narani,Reddy, Kannapu Hari Prasad,Prasad, Ganjala Venkata Siva,Rama Rao, Kamaraju Seetha,Burri, David Raju
-
scheme or table
p. 5 - 9
(2012/06/16)
-
- Kinetic control wins out over thermodynamic control in Friedel-Crafts acyl rearrangements
-
1,5-, 1,8- and 9,10-diacetylanthracenes undergo Friedel-Crafts acyl rearrangements in polyphosphoric acid at 130-150 °C to give 3-methylbenz[de]anthracen-1-one via the kinetically-controlled 1,9-diacetylanthracene. The rearrangement mechanism is supported by DFT calculations of diacetylanthracenes, their σ-complexes, O-protonates, and O,O-diprotonates. The importance of kinetic control versus thermodynamic control in Friedel-Crafts acyl rearrangements is highlighted. Certain features of reversibility are also suggested.
- Mala'bi, Tahani,Pogodin, Sergey,Agranat, Israel
-
body text
p. 1854 - 1857
(2011/04/26)
-
- A general synthetic strategy for the design of new BODIPY fluorophores based on pyrroles with polycondensed aromatic and metallocene substituents
-
BODIPYrrole: A general strategy for the design of novel BODIPY fluorophores based on pyrroles with polycondensed aromatic and metallocene substituents has been developed. The strategy involves the acylation of the condensed substituent and treatment of the acylated derivative (as oxime) with acetylene in MOH/DMSO (M=alkali metal) to give pyrroles that were then used for assembly of the BODIPY fluorophores (see scheme).
- Yu.schmidt, Elena,Zorina, Nadezhda V.,Yu.dvorko, Marina,Protsuk, Nadezhda I.,Belyaeva, Kseniya V.,Clavier, Gilles,Meallet-Renault, Rachel,Vu, Thanh T.,Mikhaleva, Al'Bina I.,Trofimov, Boris A.
-
body text
p. 3069 - 3073
(2011/04/24)
-
- Reversible Friedel-Crafts acylations of anthracene: Rearrangements of acetylanthracenes
-
Treatment of 1-acetylanthracene (1-AcAN) and 9-acetylanthracene (9-AcAN) with PPA at 80-120 °C leads to the nearly complete conversion of these isomers into 2-acetylanthracene (2-AcAN), an illustration of the Agranat-Gore rearrangement of polycyclic aromatic ketones (PAKs). Ab initio MP2/6-31(d) calculations predict the following order of stabilities: for O-complexes: 9-AcAN>1-AcAN>2-AcAN; for ketones: 2-AcAN>1-AcAN>9-AcAN; for O-protonated ketones: 2-AcAN>1-AcAN>9-AcAN. Thus, 9-AcAN is the kinetically controlled product, whereas 2-AcAN is the thermodynamically controlled product. No reverse rearrangements of 2-AcAN to either 9-AcAN or 1-AcAN and of 1-AcAN to 9-AcAN were observed. The results strengthen the pattern of reversibility in Friedel-Crafts acylations of PAHs.
- Mala'bi, Tahani,Pogodin, Sergey,Agranat, Israel
-
experimental part
p. 237 - 241
(2010/04/23)
-
- Unusual inhibition effect of 1-(1-naphthyl)-1-methylethylhydroperoxide on the liquid-phase oxidation of isopropylarenes. GC-MS and theoretical studies of the thermal decomposition of 1-naphthyl- and 1-anthryl-1- methylethylhydroperoxides
-
All five possible 1-aryl-1methylethylhydroperoxides derived from naphthalene and anthracene were synthesized and their thermal decomposition in GC-MS conditions was investigated to explain the unusual inhibition effect of 1-(1-naphthyl)-1-methylethylhydroperoxide on the liquid-phase oxidation of isopropylarenes. 2-(1-Aryloxy)propenes were identified as the main decomposition products of 1-(1-naphthyl)-1-methylethylhydroperoride and 1-(1-anthryl)-1- methylethylhydroperoxide. The relatively unstable 2-aryloxypropenes have thus far never been described as thermal decomposition products of 1-aryl-1-methylethylhydroperoxides. The plausible mechanism of the formation of 2-(1-aryloxy)propenes was proposed on the basis of AM-1 calculations of the possible rearrangement paths of the alkoxy radicals derived from the investigated hydroperoxides. The mechanism explains the inhibition effect of 1-(1-naphthyl)-1-methylethylhydroperoxide on the oxidation of isopropylarenes.
- Mazurkiewicz, Roman,Zawadiak, Jan,Orlinska, Beata,Hefczyc, Barbara,Stec, Zbigniew,Grymel, Miroslawa,Fiedorow, Piotr,Koroniak, Henryk
-
p. 289 - 295
(2012/12/22)
-
- Friedel-Crafts reactions in room temperature ionic liquids
-
Friedel-Crafts reactions in the ionic liquid system 1-methyl-3-ethylimidazolium chloride-aluminium(III) chloride can be performed with excellent yields and selectivities, and in the case of anthracene, have been found to be reversible.
- Adams, Christopher J.,Earle, Martyn J.,Roberts, Glyn,Seddon, Kenneth R.
-
p. 2097 - 2098
(2007/10/03)
-