01583nas a2200181 4500008004100000022001400041245007200055210006900127260007100196300001400267490000700281520092200288100001901210700001901229700001901248700002901267856010501296 2005 eng d a0888-588500aHydrodynamics of trickle-bed reactors: experiments and CFD modeling0 aHydrodynamics of tricklebed reactors experiments and CFD modelin a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcAUG a6278-62940 v443 a

{Hydrodynamics of trickle-bed reactors involve complex interactions of gas and liquid phases with packed solids. Such complex interactions manifest in different flow regimes occurring in trickle-bed reactors. Knowledge of prevailing flow regime, pressure drop, and liquid holdup is essential for design and performance evaluation of the reactor. Detailed knowledge of fluid dynamics is essential for ``a priory'' predictions as well as for interpretation of available data. In this study, we have used wall pressure fluctuation measurements to identify prevailing flow regime in trickle beds. Experiments were carried out on two scales of columns (of diameter 10 cm and 20 cm) with two sets of particles (3 min and 6 mm diameter spherical particles). Effects of prewetted and unwetted bed conditions on pressure drop and liquid holdup were reported for a range of operating conditions (V-G = 0.22-0.44 kg/m(2)s

1 aGunjal, P., R.1 aKashid, M., N.1 aRanade, V., V.1 aChaudhari, Raghunath, V. uhttps://library.ncl.res.in/content/hydrodynamics-trickle-bed-reactors-experiments-and-cfd-modeling-101631nas a2200229 4500008004100000022001400041245010700055210006900162260007300231300001200304490000800316520077600324653002701100653002101127653002301148653001301171653001201184100002601196700002201222700002901244856012801273 2005 eng d a1381-116900aHydroformylation of 1-hexene using Rh/TPPTS complex exchanged on anion exchange resin: kinetic studies0 aHydroformylation of 1hexene using RhTPPTS complex exchanged on a aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcMAY a179-1860 v2323 a

The exchange of the Rh/Triphenylphosphine trisulfonate sodium [TPPTS] complex on to an anion exchange resin results in a stable heterogenized catalyst for the hydroformylation of alkenes. The kinetics of hydroformylation of 1-hexene using Rh/TPPTS complex exchanged on anion exchange resin to Amberlite IRA-93 has been investigated for the first time. The rate of the reaction was found to be dependent on the partial pressure of hydrogen and 1-hexene concentrations with a first order. A maximum in the rate with increasing partial pressure of carbon monoxide was observed. A rate model has been proposed which predicts the observed rate data within reasonable error. The activation energy was found to be 84.37 kJ/mol. (c) 2005 Elsevier B.V. All rights reserved.

10aheterogenized catalyst10aHydroformylation10aion-exchange resin10akinetics10aRhodium1 aDiwakar, Makarand, M.1 aDeshpande, R., M.1 aChaudhari, Raghunath, V. uhttps://library.ncl.res.in/content/hydroformylation-1-hexene-using-rhtppts-complex-exchanged-anion-exchange-resin-kinetic-101198nas a2200229 4500008004100000022001400041245008600055210006900141260005700210300001200267490000800279520041000287653001900697653002100716653002100737653001200758653001200770100001800782700002200800700002900822856011700851 2006 eng d a1011-372X00aHydroformylation of olefins using dispersed molecular catalysts on solid supports0 aHydroformylation of olefins using dispersed molecular catalysts  a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGERcAUG a129-1330 v1103 a

A new method for heterogenization of metal complex catalysts by precipitation of its water-soluble analogue as a Gr.2 metals (Ca, Sr or Ba) salt on porous supports has been proposed. This technique yields a highly dispersed catalyst having a significantly higher activity (TOF) for hydroformylation of olefins compared to other known heterogenized catalysts. The catalyst can be recycled with ease.

10acarbon support10aHeterogenization10aHydroformylation10aOlefins10aRhodium1 aPagar, N., S.1 aDeshpande, R., M.1 aChaudhari, Raghunath, V. uhttps://library.ncl.res.in/content/hydroformylation-olefins-using-dispersed-molecular-catalysts-solid-supports-001244nas a2200265 4500008004100000022001400041245007100055210006700126260008600193300001200279490000700291520036600298653000600664653001600670653002000686653001400706653001800720100002500738700002100763700002500784700002000809700002100829700002900850856009900879 2008 eng d a0039-791100aHighly efficient sulfimidation of 1,3-dithianes by Cu(I) complexes0 aHighly efficient sulfimidation of 13dithianes by CuI complexes a325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USAbTAYLOR & FRANCIS INCcFEB a619-6250 v383 a

A series of four Cu(I) complexes were tested for sulfimidation of 1,3-dithianes in the presence of [N-(p-tolysulfonyl)imino]phenyliodinane (PhI = NTs) as the nitrene-transfer agent. Cu(TMPhen)(PPh3)Br is an efficient catalyst with more than 90% yield of the corresponding product with less reaction time as compared to the literature copper(I) complexes.

10a110a3-dithianes10aCu(I) complexes10aPhI = NTs10asulfimidation1 aGiribabu, Lingamallu1 aSingh, Surya, P.1 aPatil, Nandkumar, M.1 aKantam, Lakshmi1 aGupte, Sunil, P.1 aChaudhari, Raghunath, V. uhttps://library.ncl.res.in/content/highly-efficient-sulfimidation-13-dithianes-cui-complexes-002512nas a2200229 4500008004100000022001400041245015100055210006900206260007300275300001400348490000600362520159700368653002101965653003301986653002402019653001102043100002102054700002102075700002602096700002902122856013102151 2008 eng d a1566-736700aHighly selective synthesis of mono-ethylene glycol phenyl ethers via hydroxyalkoxylation of phenols by cyclic carbonates using large pore zeolites0 aHighly selective synthesis of monoethylene glycol phenyl ethers  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcAPR a1649-16550 v93 a

Hydroxyalkoxylation of phenols by cyclic carbonates catalyzed by alkali loaded large pore zeolites has been reported. The study shows that KL type zeolite was recyclable and selective in producing mono-ethylene glycol pheryl ethers in similar to 98.5% yield. Various substituted simple phenols were converted into mono-ethylene glycol ether of phenols with over 90% yields, except 3-bromo and 2-methyl phenols. Mono hydroxyl plienols such as hydroquinone, biphenol and BPA (2,2-bis(4-hydroxyphenyl)propane) also produce corresponding mono- and di-ethylene glycol ethers. The ratio of ethylene carbonate to phenol was found to be critical for selective formation of monoethylene glycol phenyl ether of phenols. A ratio of two results in formation of appreciable amount of diether derivative viz., 2-(2-phenoxyethoxy) ethanol. Compared to ethylene carbonate, a lower reactivity of 1,2-propane carbonate was found for hydroxyalkoxylation of phenol. It was found that ring opening at less hindered methylene carbon of 1,2-propylene carbonate prevailed giving rise to selective formation of beta-hydroxy phenyl ethers. The reactivity of ethylene carbonate towards O-alkylation versus transesterification of phenol has been explained on the basis of HSAB concept. Finally, it has been shown that yield of mono-ethylene glycol phenyl ether is controlled both by basicity and channel architecture of zeolite structure. KL zeolite was found to be the most effective zeolite because of it's intermediate basicity and one dimensional channel architect. (C) 2008 Elsevier B.V. All rights reserved.

10acyclic carbonate10aethylene glycol phenyl ether10ahydroxyalkoxylation10aphenol1 aKinage, Anil, K.1 aGupte, Sunil, P.1 aChaturvedi, Rajiv, K.1 aChaudhari, Raghunath, V. uhttps://library.ncl.res.in/content/highly-selective-synthesis-mono-ethylene-glycol-phenyl-ethers-hydroxyalkoxylation-phenols-002168nas a2200241 4500008004100000022001400041245012000055210006900175260007300244300001200317490000800329520127700337653001801614653002401632653001301656653002201669653001901691653001401710100002101724700002501745700002901770856012701799 2009 eng d a1381-116900aHydroesterification of 2-vinyl-6-methoxynaphthalene using palladium complexes containing chelating nitrogen ligands0 aHydroesterification of 2vinyl6methoxynaphthalene using palladium aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJUL a134-1410 v3073 a

Hydroesterification of 2-vinyl-6-methoxynaphthalene (VMN) to methyl ester of 6-methoxy naphthyl propionic acid (ester of naproxen) has been investigated using palladium complexes containing the chelating N(boolean AND)O and N(boolean AND)N ligands (pyridine-2-carboxylate, 2-acetylpyridine, 2-pyridine-carboxaldehyde, and bipyridine) as catalysts. Palladium complex containing 2-acetylpyridine as the ligand was found to be superior to other Pd-complexes. Both acid and halide promoters were necessary for high activity and selectivity. As an acid promoter, benzenesulfonic acid was found to be more effective compared to p-toluenesulfonic acid. Formation of ether 2-methoxy-6-(1-methoxyethyl)naphthalene and a polymer of VMN was observed in all the reactions. It was observed that active catalytic species generated during carbonylation reaction was responsible for the polymer formation. The effect of various parameters such as solvents, CO pressure, and alcohols on the catalytic activity as well as the selectivity was investigated. The turnover frequency using the complex Pd(acpy)(PPh(3))(OTs)(2) (acpy = 2-acetylpyridine) catalyst was found to be 42 h(-1), which is the highest for the hydroesterification of VMN. (C) 2009 Elsevier B.V. All rights reserved.

10aCarbonylation10aHydroesterification10aNaproxen10aPalladium complex10aPolymer of VMN10aPromoters1 aAtla, Shashi, B.1 aKelkar, Ashutosh, A.1 aChaudhari, Raghunath, V. uhttps://library.ncl.res.in/content/hydroesterification-2-vinyl-6-methoxynaphthalene-using-palladium-complexes-containing-002395nas a2200169 4500008004100000022001400041245011900055210006900174260007100243300001400314490000700328520168200335100002302017700002502040700002902065856013102094 2009 eng d a0888-588500aHydroformylation of 1,4-diacetoxy-2-butene using HRh(CO)(PPh3)(3) tethered on alumina as a catalyst: kinetic study0 aHydroformylation of 14diacetoxy2butene using HRhCOPPh33 tethered a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcNOV a9479-94890 v483 a

Hydroformylation of 1,4-diacetoxy-2-butene (DAB) was studied using [HRh(CO)(PPh3)(3)] complex catalyst tethered on alumina using phosphotungstic acid (PTA) as an anchoring agent, with the aim to understand the product distribution, selectivity, and intrinsic kinetics. It was observed that with the tethered heterogeneous catalyst a simultaneous hydroformylation followed by deacetoxylation steps was possible, which is relevant for combining two steps in the sequence of synthesis of vitamin-A intermediate [2-formyl-4-acetoxy butene (FAB)]. P-31 cross-polarization magic angle spinning nuclear magnetic resonance (CP MAS NMR) and infrared (IR) instrumental techniques were found be the most effective techniques to establish the catalyst structure and true heterogeneity. On the basis of the spectroscopic evidence, we postulate the loss of a PPh3 group during tethering to give HRh(CO)(PPh3)(2)-PTA-Al2O3 as a heterogeneous complex catalyst. Experimental data on the concentration-time and CO/H-2 consumption-time profiles were obtained and the effects of DAB concentration, CO partial pressure, H-2 partial pressure, and catalyst loading were studied in a 50 mL stirred batch reactor over a temperature range of 338-358 K. The analysis of solid-liquid-gas mass transfer effects was investigated to ensure that the reaction was operating in the kinetic regime Various models were developed, and the best model was chosen by a model discrimination procedure. The agreement between the model prediction and the experimental data was found to be excellent. The activation energies for the hydroformylation and deacetoxylation steps were found to be 42.5 and 80.2 kJ/mol.

1 aChansarkar, Rashmi1 aKelkar, Ashutosh, A.1 aChaudhari, Raghunath, V. uhttps://library.ncl.res.in/content/hydroformylation-14-diacetoxy-2-butene-using-hrhcopph33-tethered-alumina-catalyst-kinetic-002272nas a2200229 4500008004100000022001400041245012300055210006900178260007300247300001000320490000800330520141000338653001401748653001701762653001101779653002801790653002501818100002501843700002101868700002901889856012401918 2010 eng d a0926-860X00aHeterogenized copper catalysts for the amination of arylhalide: synthesis, characterization and catalytic applications0 aHeterogenized copper catalysts for the amination of arylhalide s aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJAN a73-810 v3723 a

This research investigated the synthesis, characterization and catalytic activity of heterogenized copper complexes for the selective amination of aryl halides. Amination reactions using homogeneous copper catalyst systems are not generally selective and it is also difficult to recover the catalyst from the homogeneous system for recycling. To overcome these difficulties, our efforts were directed towards the development of cheaper heterogeneous catalyst systems, which can be easily recovered and recycled. Heterogenized analogs of the homogenous Cu complexes were prepared using two methods: (a) encapsulation of copper complexes in zeolite-Y and (b) tethering of copper complexes on various supports like zeolite-Y, silica, charcoal, or clay. The encapsulated and tethered copper catalysts on zeolite-Y were characterized using EPR, Diffused reflectance UV-vis, XRD, IAS, ICPES, SEM, and TEM. The results confirmed that the copper complexes were truly heterogenized in zeolite-Y support. Encapsulated and tethered copper complexes were tested for amination of aryl iodide. The effects of various reaction parameters were examined using tethered Cu(Phen)(PPh(3))Br-PTA-Y catalyst to determine optimum conditions. A recycle study of encapsulated and tethered Cu catalyst was carried out to test their robustness for possible commercial exploitation. (C) 2009 Elsevier B.V. All rights reserved.

10aAmination10aC-N coupling10aCopper10aheterogeneous catalysis10amesoporous materials1 aPatil, Nandkumar, M.1 aGupte, Sunil, P.1 aChaudhari, Raghunath, V. uhttps://library.ncl.res.in/content/heterogenized-copper-catalysts-amination-arylhalide-synthesis-characterization-and-0