@article { ISI:000230389700019, title = {Bis(2-[alpha-hydroxyethyl]benzimidazolato)copper(II) anchored onto chloromethylated polystyrene for the biomimetic oxidative coupling of 2-aminophenol to 2-aminophenoxazine-3-one}, journal = {Journal of Molecular Catalysis A - Chemical}, volume = {236}, number = {1-2}, year = {2005}, month = {JUL}, pages = {132-138}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

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.

}, keywords = {2-aminophenol, 2-aminophenoxazine-3-one, bis(2-[alpha-hydroxyethyl]benzimidazolato)copper(II), chloromethylated polystyrene, oxidative coupling}, issn = {1381-1169}, doi = {10.1016/j.molcata.2005.02.034}, author = {Maurya, Mannar R. and Sikarwar, S. and Joseph, Trissa and Halligudi, Shivappa B.} } @article { ISI:000229488700014, title = {Bronsted acidic ionic liquids: a green, efficient and reusable catalyst system and reaction medium for fischer esterification}, journal = {Journal of Molecular Catalysis A - Chemical}, volume = {234}, number = {1-2}, year = {2005}, month = {JUN}, pages = {107-110}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

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.

}, keywords = {acids, alcohol and reaction medium, Fischer esterification, Ionic liquid}, issn = {1381-1169}, doi = {10.1016/j.molcata.2005.03.005}, author = {Joseph, Trissa and Sahoo, S. and Halligudi, Shivappa B.} } @article { ISI:000230389700020, title = {Copper(II) ion-exchanged montmorillonite as catalyst for the direct addition of N-H bond to CC triple bond}, journal = {Journal of Molecular Catalysis A - Chemical}, volume = {236}, number = {1-2}, year = {2005}, month = {JUL}, pages = {139-144}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

An efficient synthesis of phenyl-(1-phenylethylidene)amine using copper-exchanged montmorillonite clay (Cu K-10) is demonstrated. The catalyst was characterized using UV-vis, XRD, BET surface area measurements, pyridine adsorption etc. The XRD and surface area measurement show that the structural characteristics of the support montmorillonite K-10 (K-10) are preserved after Cu exchange. The hydroamination of phenyl acetylene with aniline was carried out in toluene under reflux condition in N-2 atmosphere at 393 K. The reaction is highly regio-selective for only Markovnikoff{\textquoteright}s addition of an-tine to CC multiple bond and proceeded smoothly to completion. The reaction conditions were optimized to obtain complete conversion with respect to phenyl acetylene. Reaction data showed that the activity of the catalyst in hydroamination reaction is greater at higher reaction temperatures and nonpolar solvents and NZ pressure promotes the reaction drastically. (c) 2005 Elsevier B.V. All rights reserved.

}, keywords = {alkyne, Aniline, Catalyst, hydroamination, K-10 montmorillonite clay, phenyl acetylene}, issn = {1381-1169}, doi = {10.1016/j.molcata.2005.04.022}, author = {Joseph, Trissa and Shanbhag, G. V. and Halligudi, Shivappa B.} } @article { ISI:000227266100034, title = {Oxyfunctionalization of limonene using vanadium complex anchored on functionalized SBA-15}, journal = {Journal of Molecular Catalysis A-Chemical}, volume = {229}, number = {1-2}, year = {2005}, month = {MAR}, pages = {241-247}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

VO(Salten) complexes, where Salten = 3-[N,N{\textquoteright}-bis-3(salicylidenamino)ethyltriamine], have been covalently anchored on to functionalized SBA-15. The formation and integrity of the complex have been confirmed by elemental analysis, Fr-IR, X-ray diffraction (XRD) and BET measurements and the complex was used for the oxyfunctionalization of limonene in presence of urea hydroperoxide (UHP) as the oxidizing agent. The oxyfunctionalization of limonene resulted in limonene oxide, carvone, carvacrol and carveol. Anchored complex showed better catalytic activity than the neat complex, while the neat complexes has deactivated in the reaction due to formation of inactive alpha-oxo-bridged dimers, the covalently anchored complexes remained stable throughout the reaction. The anchored complex could be easily separated from the products and could be reused. (C) 2004 Elsevier B.V. All rights reserved.

}, keywords = {covalently anchored vanadium complex, functionalized Si-SBA-15, limonene, oxofunctionalization, UHP}, issn = {1381-1169}, doi = {10.1016/j.molcata.2004.12.008}, author = {Joseph, Trissa and Halligudi, Shivappa B.} } @article { ISI:000228779100008, title = {Synthesis, characterization and catalytic potentials of polymer anchored copper(II), oxovanadium(IV) and dioxomolybdenum(VI) complexes of 2-(alpha-hydroxymethyl)benzimidazole}, journal = {Reactive \& Functional Polymers}, volume = {63}, number = {1}, year = {2005}, month = {MAR}, pages = {71-83}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

{2-(alpha-Hydroxymethyl)benzimidazole (Hhmbmz) has been covalently anchored to chloromethylated polystyrene cross-linked with 5\% divinylbenzene. This chelating resin reacts with cupric acetate, vanadyl sulphate and [MoO(2)-(acac)(2)] (Hacac = acetylacetone) in presence of Hhmbmz to give complexes PS-[Cu(hmbmz)(2)], PS-[VO(hmbmz)(2)] and PS-[MoO(2)(hmbmz)(2)] (where

}, keywords = {2-(alpha-hydroxymethyl)benzimidazole, oxidation of styrene and ethyl benzene, oxidative bromination of salicylaldehyde, polymer anchored-complexes}, issn = {1381-5148}, doi = {10.1016/j.reactfunctpolym.2005.02.008}, author = {Maurya, Mannar R. and Sikarwar, S. and Joseph, Trissa and Manikandan, Palanichamy and Halligudi, Shivappa B.} } @article { ISI:000237318000033, title = {Chemoselective anti-Markovnikov hydroamination of alpha,beta-ethylenic compounds with amines using montmorillonite clay}, journal = {Journal of Molecular Catalysis A-Chemical}, volume = {250}, number = {1-2}, year = {2006}, month = {MAY}, pages = {210-217}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

The catalytic activity of montmorillonite clays as a catalyst for the hydroamination of alpha,beta-ethylenic compounds with amines was tested. Aniline and substituted amines reacted with alpha,beta-ethylenic compounds in the presence of catalytic amount of commercially available clay to afford exclusively anti-Markovnikov adduct in excellent yields. Aniline reacted with ethyl acrylate to yield only anti-Markovnikov adduct N-[2-(ethoxycarbonyl)ethyl] aniline (mono-addition product). No Markovnikov adduct (N-[1-(ethoxycarbonyl)ethyl]aniline and double addition product N,N-bis[2-(ethoxycarbonyl)ethyl]aniline were formed under selected reaction conditions. For a better exploitation of the catalytic activity in terms of increased activity and improved selectivity for the mono-addition product, the reaction parameters were optimized in terms of temperature, solvent, reactant mole ratio. Under optimized reaction conditions, montmorillonite clay K-10 showed a superior catalytic performance in the hydroamination of ethyl acrylate with aniline with a conversion of aniline to mono-addition product (almost 100\% chemoselectivity) with a high rate constant 0.3414 min(-1) compared to the reported protocols. The dependence of conversion of aniline over different types of montmorillonite clays (K-10, K-20, K-30, Al-Pillared clay and untreated clay) has also been discussed. The activities of clay for the hydroamination of different aromatic and aliphatic amines have also been investigated. Under harsh reaction conditions (increased temperature and long reaction time) small amounts of di-addition products were observed. The kinetics data has been interpreted using the initial rate approach model. (c) 2006 Elsevier B.V. All rights reserved.

}, keywords = {alpha, amines, anti-Markovnikov addition product, beta-ethylenic compounds, chemo-selective, hydroamination, K-10 montmorillonite clay}, issn = {1381-1169}, doi = {10.1016/j.molcata.2006.01.062}, author = {Joseph, Trissa and Shanbhag, G. V. and Sawant, D. P. and Halligudi, Shivappa B.} } @article { ISI:000243163000080, title = {Au-Pt nanoparticles in amine functionalized MCM-41: catalytic evaluation in hydrogenation reactions}, journal = {Catalysis Communications}, volume = {8}, number = {3}, year = {2007}, month = {MAR}, pages = {629-634}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Nano-sized Au-Pt nanoparticles (Au-Pt-bi-MNPs) have been synthesized by the simultaneous reduction of HAuCl4 and HPtCl6 by NaBH4 inside the channels of amine functionalized Si-MCM-41 (NH2-Si-MCM-41) at ambient conditions. These materials were characterized using chemical analysis, UV-vis, XPS, XRD, FT-IR, Surface area and TEM analysis. The size of these alloyed nanoparticles (bi-MNPs) were found in the range of 2-4 nm. These nanoparticles were evaluated to study their catalytic activities towards hydrogenation of aromatic nitro compounds. The catalytic activity of the Au-Pt bi-MNPs was found to be superior to monometallic An nanoparticles. (c) 2006 Published by Elsevier B.V.

}, keywords = {amine-functionalized MCM-41, Au-Pt nanoparticles, Catalytic hydrogenation}, issn = {1566-7367}, doi = {10.1016/j.catcom.2006.03.004}, author = {Joseph, Trissa and Kumar, K. Vijay and Ramaswamy, A. V. and Halligudi, Shivaraj B.} } @article { ISI:000249564600009, title = {Copper(II) ion exchanged A1SBA-15: a versatile catalyst for intermolecular hydroamination of terminal alkynes with aromatic amines}, journal = {Journal of Catalysis}, volume = {250}, number = {2}, year = {2007}, month = {SEP}, pages = {274-282}, publisher = {ACADEMIC PRESS INC ELSEVIER SCIENCE}, type = {Article}, address = {525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA}, abstract = {

The hydroarnination reaction offers a very attractive route for the synthesis of alkylated amines and their derivatives with no byproduct formation. AISBA-15 was synthesized by isomorphous substitution of aluminum into the framework of SBA-15, which induces the Bronsted acid sites, and these were exchanged with metal ions such as Cu2+, Zn2+, and Pd2+. The catalysts were characterized by XRD, N-2-sOrption, SEM, TEM, acidity measurements by FT-IR pyridine adsorption, H-2-TPR, (27)AI MAS NMR, and Si-29 MAS NMR. Hydroamination of phenylacetylene (PhAc) with 2,4-xylidine has been used as a test reaction, which gave N-(1-phenylethylidene)-2,4-dimethylaniline with no byproduct formation. CuAlSBA-15 and CuAIMCM-41 showed around three times greater activity in hydroamination of PhAc compared with Cu-clay and Cu-beta, due to the moderate Lewis acidity of Cu2+ present in mesoporous supports. The performance of the CuAlSBA-15 was also determined with different alkynes and amines to evaluate the catalyst{\textquoteright}s general applicability in hydroamination reactions. (c) 2007 Elsevier Inc. All rights reserved.

}, keywords = {A1SBA-15, addition, alkyne, Amine, Copper catalyst, heterogeneous, hydroamination, ion exchange, Mesoporous}, issn = {0021-9517}, doi = {10.1016/j.jcat.2007.06.007}, author = {Shanbhag, Ganapati V. and Joseph, Trissa and Halligudi, Shivaraj B.} }