02262nas a2200241 4500008004100000022001400041245010100055210006900156260007300225300001200298490000700310520141400317653001501731653001301746653001601759653001101775100001301786700001901799700002101818700002101839700002801860856013201888 2005 eng d a1387-181100aBenzylation of benzene and other aromatics by benzyl chloride over mesoporous AlSBA-15 catalysts0 aBenzylation of benzene and other aromatics by benzyl chloride ov aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcMAY a195-2030 v803 a

Aluminum-containing mesoporous molecular sieves AISBA-15 with different n(Si)/n(Al), ratios and AIMCM-41 have been synthesized hydrothermally and characterized in detail by physicochemical methods, viz. XRD, N(2) adsorption and (27)Al NMR spectroscopy. The low angle XRD and N2 adsorption measurements reveal that the structural order of SBA-15 was retained after the incorporation of Al. The increase of the unit cell parameter with increasing aluminum content and (27)Al MAS NMR spectroscopy confirm the incorporation of aluminum in the framework. Benzylation of benzene and substituted benzenes reaction employing benzyl chloride as the alkylating agent over AISBA-15 and AIMCM-41 have been investigated. The influence of various reaction parameters such as reaction temperature, reactant feed ratio and catalyst amount affecting the activity and selectivity of AISBA-15, have been studied. Among the mesoporous catalysts studied, AISBA-15(45), where the number in parentheses indicates the molar nsilnA, ratio, shows both high conversion and high selectivity for the benzylation of benzene. The activity of this catalyst for the benzylation of different aromatic compounds is in the following order: benzene > toluene > p-xylene > mesitylene > anisole. Kinetics of the benzene benzylation over different catalysts have also been investigated. (c) 2005 Elsevier Inc. All rights reserved.

10aAlkylation10aAlSBA-1510aBenzylation10aSBA-151 aVinu, A.1 aSawant, D., P.1 aAriga, Katsuhiko1 aHartmann, Martin1 aHalligudi, Shivappa, B. uhttps://library.ncl.res.in/content/benzylation-benzene-and-other-aromatics-benzyl-chloride-over-mesoporous-alsba-15-catalysts-002326nas a2200241 4500008004100000022001400041245018300055210006900238260007300307300001200380490000800392520131100400653001801711653002901729653005701758653003301815653002301848100002301871700001701894700001901911700002801930856012601958 2005 eng d a1381-116900aBis(2-[alpha-hydroxyethyl]benzimidazolato)copper(II) anchored onto chloromethylated polystyrene for the biomimetic oxidative coupling of 2-aminophenol to 2-aminophenoxazine-3-one0 aBis2alphahydroxyethylbenzimidazolatocopperII anchored onto chlor aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJUL a132-1380 v2363 a

2-(alpha-Hydroxyethyl)benzimidazole (Hhebmz) has been covalently anchored to chloromethylated polystyrene cross-linked with 5% divinylbenzene. This polymer-anchored chelating resin reacts with cupric acetate in presence of Hhebmz to give polymer-anchored copper(II) complex PS-[Cu(hebmz)(2)]. Elemental analyses, FT-IR, electronic, scanning electron micrographs (SEM) and TGA-DTA pattern have been used to characterize the complex. Oxidative coupling of 2-aminophenol (OAP) to 2-aminophenoxazine-3-one (APX) catalyzed by PS-[Cu(hebmz)(2)] in presence of air at 70 degrees C in DMF gave 62% substrate conversion over a period of 8 h. Kinetics of the above reaction indicated that the rate of oxidative coupling of OAP has a first order dependence with respect to substrate, catalyst and air pressure (dissolved O-2) concentrations in the range of conditions evaluated. Based on these observations, a plausible mechanism for the above reaction has been proposed. From, the study on the effect of temperature on the rates of oxidative coupling, an activation energy 34.2 kcal/degree mole was evaluated from Arrhenius plot of -ln rate versus 1/T. Enthalpy, entropy and free energy were calculated using standard thermodynamic equations for the above reaction. (c) 2005 Elsevier B.V. All rights reserved.

10a2-aminophenol10a2-aminophenoxazine-3-one10abis(2-[alpha-hydroxyethyl]benzimidazolato)copper(II)10achloromethylated polystyrene10aoxidative coupling1 aMaurya, Mannar, R.1 aSikarwar, S.1 aJoseph, Trissa1 aHalligudi, Shivappa, B. uhttps://library.ncl.res.in/content/bis2-alpha-hydroxyethylbenzimidazolatocopperii-anchored-chloromethylated-polystyrene-101799nas a2200217 4500008004100000022001400041245013000055210006900185260007300254300001200327490000800339520095800347653001001305653003201315653002701347653001701374100001901391700001401410700002801424856012901452 2005 eng d a1381-116900aBronsted acidic ionic liquids: a green, efficient and reusable catalyst system and reaction medium for fischer esterification0 aBronsted acidic ionic liquids a green efficient and reusable cat aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJUN a107-1100 v2343 a

Bronsted acidic ionic liquid containing nitrogen-based organic cations 1-methylimidazole and 1-butyl-3-methylimidazolium and inorganic anions of the type BF4-, PF6- and PTSA(-) has been synthesized in good yields and used as a catalysts and reaction medium for Fischer esterification of alcohols with acids. These were characterized using FTIR and NMR spectroscopy. Ionic liquids as catalyst afforded good alcohol conversion and excellent ester selectivity. Fischer esterification of acetic acid with benzyl alcohol with different Bronsted acidic ionic liquids was carried out. Maximum substrate conversion 100 % and product selectivity 100 % was observed on using [BMIM](+)PTSAas catalyst over a period of 2 h. The ester was easily separated from the reaction mixture and the ionic liquid was reused four times after removing water. No significant loss in catalytic activity was observed on recycling. (c) 2005 Elsevier B.V. All rights reserved.

10aacids10aalcohol and reaction medium10aFischer esterification10aIonic liquid1 aJoseph, Trissa1 aSahoo, S.1 aHalligudi, Shivappa, B. uhttps://library.ncl.res.in/content/bronsted-acidic-ionic-liquids-green-efficient-and-reusable-catalyst-system-and-reaction-1