01080nas a2200205 4500008004100000022001400041245011600055210006900171260008400240300001200324490000700336520024600343100002600589700002800615700002100643700002500664700002500689700002900714856013100743 2008 eng d a0366-702200aHighly active nanostructured Co3O4 catalyst with tunable selectivity for liquid phase air oxidation of p-cresol0 aHighly active nanostructured Co3O4 catalyst with tunable selecti a1-5 KANDA-SURUGADAI CHIYODA-KU, TOKYO, 101-8307, JAPANbCHEMICAL SOC JAPANcMAR a310-3110 v373 a

This is a first report of highly efficient heterogeneous nanostructured Co3O4 catalyst (6-8 nm) having high surface area (95 m(2)/g) developed for selective liquid phase air oxidation of p-cresol under atmospheric pressure conditions.

1 aKshirsagar, Vikas, S.1 aVijayanand, Subramanian1 aPotdar, Hari, S.1 aJoy, Pattayil, Alias1 aPatil, Kashinath, R.1 aRode, Chandrashekhar, V. uhttp://library.ncl.res.in/content/highly-active-nanostructured-co3o4-catalyst-tunable-selectivity-liquid-phase-air-oxidation-001505nas a2200193 4500008004100000022001400041245008600055210006900141260007100210300001400281490000700295520076900302100002601071700002101097700002501118700002401143700002901167856011501196 2009 eng d a0888-588500aHeterogeneous cobalt-saponite catalyst for liquid phase air oxidation of p-cresol0 aHeterogeneous cobaltsaponite catalyst for liquid phase air oxida a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcNOV a9423-94270 v483 a

Heterogeneous Co-saponite was found to be an efficient catalyst for the liquid phase oxidation of p-cresol under mild conditions. Divalent cobalt tons were found to be in both the tetrahedral and octahedral positions of the saponite clay. Studies on the effect of reaction parameters showed that the rate of reaction increased with increase in Co loading from 5 to 13% and then remained constant up to 30% of Co loading, while the rate of oxidation showed a first-order dependence on the partial pressure of oxygen up to 300 kPa. Results of oxidation experiments over Co-saponite, in an Inert atmosphere, and the XPS studies Suggest Mars-van Krevelen pathway operating, which involves lattice oxygen of Co-saponite in the liquid phase oxidation of p-cresol.

1 aKshirsagar, Vikas, S.1 aGarade, Ajit, C.1 aPatil, Kashinath, R.1 aJha, Ratnesh, Kumar1 aRode, Chandrashekhar, V. uhttp://library.ncl.res.in/content/heterogeneous-cobalt-saponite-catalyst-liquid-phase-air-oxidation-p-cresol-001083nas a2200181 4500008004100000022001400041245010100055210006900156260008400225300001200309490000700321520034500328100002100673700002800694700002500722700002900747856012500776 2010 eng d a0366-702200aHydroxyalkylation of p-Cresol to 2,2 `-methylenebis(4-methylphenol) using Sn/Si-MCM-41 catalysts0 aHydroxyalkylation of pCresol to 22 methylenebis4methylphenol usi a1-5 KANDA-SURUGADAI CHIYODA-KU, TOKYO, 101-8307, JAPANbCHEMICAL SOC JAPANcFEB a126-1270 v393 a

Sn/Si-MCM-41 has exhibited an excellent catalytic activity [70% product yield with 88% selectivity to 2,2'-methylenebis(4-methylphenol)] for the selective hydroxyalkylation of p-cresol. At equal level of Sn loading, Sn/Si-MCM-41 prepared by direct hydrothermal synthesis showed higher activity than Sn-impregnated Si-MCM-41 catalyst.

1 aGarade, Ajit, C.1 aNiphadkar, Prashant, S.1 aJoshi, Praphulla, N.1 aRode, Chandrashekhar, V. uhttp://library.ncl.res.in/content/hydroxyalkylation-p-cresol-22-methylenebis4-methylphenol-using-snsi-mcm-41-catalysts-001669nas a2200241 4500008004100000022001400041245010800055210006900163260007300232300001000305490000700315520079400322653001001116653002401126653002701150653002101177653002101198653000801219100002001227700002101247700002901268856013001297 2013 eng d a1566-736700aHeterogeneous Co3O4 catalyst for selective oxidation of aqueous veratryl alcohol using molecular oxygen0 aHeterogeneous Co3O4 catalyst for selective oxidation of aqueous  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcMAR a66-690 v333 a

Nano-structured, spinel Co3O4 catalyst was developed for the aqueous phase oxidation of veratryl alcohol, which showed the highest conversion of 85% with 96% selectivity to veratryl aldehyde. The co-existence of Co3+ and Co2+ species in the octahedral and tetrahedral positions respectively, was confirmed by XPS, cyclic voltammogram, TPR and TPO characterization. The rod-like morphology of Co3O4 catalyst was confirmed by HRTEM. The effects of various reaction parameters namely, catalyst concentration, temperature and partial oxygen pressure on conversion and selectivity patterns were also studied for the oxidation of veratryl alcohol. This catalyst also showed an excellent stability as evidenced by successful reusability for three times. (C) 2012 Published by Elsevier B.V.

10aCo3O410aCyclic voltammogram10aLiquid phase oxidation10aMolecular oxygen10aVeratryl alcohol10aXPS1 aMate, Vivek, R.1 aShirai, Masayuki1 aRode, Chandrashekhar, V. uhttp://library.ncl.res.in/content/heterogeneous-co3o4-catalyst-selective-oxidation-aqueous-veratryl-alcohol-using-molecular-001684nas a2200241 4500008004100000022001400041245013600055210006900191260007700260300001400337490000700351520076700358653001201125653001201137653001401149653002801163653002101191100002201212700002501234700002301259700002901282856013101311 2013 eng d a2192-650600aHighly efficient povidone-phosphotungstic acid catalyst for the tandem acetalization of aldehydes to bis- and tris(indolyl)methanes0 aHighly efficient povidonephosphotungstic acid catalyst for the t aBOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcNOV a1393-13990 v783 a

A novel, nonleachable hybrid of heteropoly acid and polyvinylpyrrolidone (or povidone) catalyzes the acetalization of aldehydes in methanol at room temperature followed by reaction with indole to give bis(indolyl)methanes (BIMs) and tris(indolyl)methanes (TIMs) in quantitative yields (90-97%). The catalyst was shown by pyridine FTIR spectroscopy to possess BrOnsted acidity, and the hybrid formation was confirmed by XRD and (PNMR)-P-31 studies. Friedel-Crafts alkylation of indole as well as the tandem synthesis of BIMs and TIMs were established with several types of carbonyl and indole substrates to give the corresponding products quantitatively. The catalyst was recycled efficiently for three successive runs without losing its original activity.

10aacetals10aAcidity10aaldehydes10aheterogeneous catalysis10aheteropoly acids1 aKamble, Sumit, B.1 aSwami, Rameshwar, K.1 aSakate, Sachin, S.1 aRode, Chandrashekhar, V. uhttp://library.ncl.res.in/content/highly-efficient-povidone-phosphotungstic-acid-catalyst-tandem-acetalization-aldehydes-bis-001491nas a2200157 4500008004100000022001400041245012200055210006900177260011000246300001400356490000700370520078600377100001401163700002901177856012701206 2013 eng d a1144-054600aHighly selective liquid-phase aerobic oxidation of vanillyl alcohol to vanillin on cobalt oxide (Co3O4) nanoparticles0 aHighly selective liquidphase aerobic oxidation of vanillyl alcoh aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcJUN a2669-26740 v373 a

Spinel Co3O4 nanoparticles prepared by solution phase method having particle size in the range of 12-20 nm exhibited excellent activity for the liquid-phase aerobic oxidation of vanillyl alcohol with 80% conversion and 98% selectivity to vanillin. Our catalyst could be reused three times without appreciable loss in activity. The catalytic activity of the Co3O4 nanoparticles was found to be similar to its homogenous precursor (cobalt acetate) and greater than the commercial Co3O4 oxide. The detailed characterization results of morphology, size and structure of the prepared Co3O4 nanoparticles obtained by XRD, FT-IR, H-2-TPR, HR-TEM and cyclic voltammetry technique were used to understand the roles of various Co species in directing the selectivity towards vanillin.

1 aJha, Ajay1 aRode, Chandrashekhar, V. uhttp://library.ncl.res.in/content/highly-selective-liquid-phase-aerobic-oxidation-vanillyl-alcohol-vanillin-cobalt-oxide-001706nas a2200169 4500008004100000022001400041245016900055210006900224260011000293300001400403490000600417520091300423100002201336700002201358700002901380856012701409 2015 eng d a2044-475300aHighly efficient triphenyl(3-sulfopropyl)phosphonium functionalized phosphotungstic acid on silica as a solid acid catalyst for selective mono-allylation of acetals0 aHighly efficient triphenyl3sulfopropylphosphonium functionalized aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcMAY a4039-40470 v53 a

Silica supported phosphotungstic acid functionalized with triphenyl(3-sulfopropyl)phosphonium (PW-Si/TPSP) was developed as a solid acid catalyst for C-C bond formation via Hosomi-Sakurai allylation of acetals. Functionalization of PW as well as its binding to silica was confirmed by solid state P-31-NMR and Si-29-NMR, respectively. Among the various catalysts prepared, the 30% PW loaded (30PW-Si/TPSP) catalyst gave an excellent yield of homoallyl ethers (HAEs) via selective mono-allylation of acetals with allyltrimethylsilane. A plausible reaction pathway has also been proposed in which the strong Bronsted acid sites of 30PW-Si/TPSP play an important role in activating the acetals to form the corresponding oxonium cations. The versatility of our catalyst was demonstrated for the allylation of a wide variety of acetals while its stability was established in five successful recycling runs.

1 aKamble, Sumit, B.1 aShinde, Suhas, H.1 aRode, Chandrashekhar, V. uhttp://library.ncl.res.in/content/highly-efficient-triphenyl3-sulfopropylphosphonium-functionalized-phosphotungstic-acid-001810nas a2200217 4500008004100000022001400041245008200055210006900137260011000206300001400316490000600330520101100336100001401347700002001361700001701381700001801398700001801416700002901434700001901463856011001482 2015 eng d a2044-475300aHydrogen production by the water-gas shift reaction using CuNi/Fe2O3 catalyst0 aHydrogen production by the watergas shift reaction using CuNiFe2 aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcFEB a2752-27600 v53 a

Incorporation of both Cu and Ni together into the crystalline lattice of Fe2O3 results in a significant increase in the catalytic activity and also suppresses the methanation reaction in the high-temperature water-gas shift (HT-WGS) reaction. CuNi/Fe2O3 exhibited the highest CO conversion with negligible CH4 selectivity at the extremely high GHSV of 101 000 h(-1) (X-CO = 85% at 400 degrees C). The high activity of CuNi/Fe2O3 catalyst is mainly due to the increase in the lattice strain and the decrease in the binding energy of lattice oxygen. In addition, X-ray photoelectron spectroscopy (XPS) results provide direct evidence for the formation of surface CuNi alloy, which plays a critical role in suppressing the methanation reaction. The detailed characterization by powder X-ray diffraction (XRD), XPS, BET, and H-2 temperature-programmed reduction (TPR) techniques was used to understand the role of dopants on host iron oxides in the enhancement of catalytic activity for HT-WGS reaction.

1 aJha, Ajay1 aJeong, Dae-Woon1 aShim, Jae-Oh1 aJang, Won-Jun1 aLee, Yeol-Lim1 aRode, Chandrashekhar, V.1 aRoh, Hyun-Seog uhttp://library.ncl.res.in/content/hydrogen-production-water-gas-shift-reaction-using-cunife2o3-catalyst-001294nas a2200157 4500008004100000245011600041210006900157260000800226300001600234490000700250520068500257100001800942700001600960700002900976856013101005 2016 eng d00aHighly selective direct azidation of alcohols over a heterogeneous povidone-phosphotungstic solid acid catalyst0 aHighly selective direct azidation of alcohols over a heterogeneo cDEC a10240-102450 v403 aA simple protocol for the selective azidation of alcohols is developed using a solid acid hybrid of a povidone and phosphotungstic acid (PVP-PWA) using azidotrimethylsilane as an azide source at room temperature. In a broad substrate scope, various activated as well as unactivated benzylic and diphenyl alcohols were treated smoothly with TMS-N-3 to selectively produce only azide products with excellent yields in a very short reaction time of 2 h. FT-IR confirmed the stability of the catalyst with retention of the Keggins structure after the reaction. Recycling experiments demonstrated the reusability of the PVP PWA (3:1) several times without losing its original activity.1 aKamble, Sumit1 aMore, Sagar1 aRode, Chandrashekhar, V. uhttp://library.ncl.res.in/content/highly-selective-direct-azidation-alcohols-over-heterogeneous-povidone-phosphotungstic-solid03587nas a2200169 4500008004100000245013700041210006900178260000800247490000600255520282600261653010203087100002303189700002203212700002403234700002903258856013003287 2017 eng d00aHeterogeneously catalyzed domino synthesis of 3-indolylquinones involving direct oxidative C-C coupling of hydroquinones and indoles0 aHeterogeneously catalyzed domino synthesis of 3indolylquinones i cMAY0 v23 a
Abstract Image

A domino synthesis of 3-indolylquinones was achieved successfully via direct oxidative C–C coupling of hydroquinones with indoles over Ag2O and Fe3O4/povidone–phosphotungstic acid (PVP–PWA) catalysts using H2O2 in tetrahydrofuran at room temperature. Ag2O catalyzed the in situ oxidation of hydroquinone and 3-indolylhydroquinone intermediates, whereas ferrite solid acid, Fe3O4/PVP–PWA, with a 1:4:1 ratio of Fe3O4, PVP, and PWA, catalyzed the activation of quinones. The efficiency of this catalytic domino approach was established by a broad scope of substrates involving a variety of hydroquinones and quinones to give high yields (81–97%) of 3-indolylquinones. Fe3O4/PVP–PWA was separated magnetically, whereas simple filtration could separate Ag2O, both of which could be recycled several times without losing their activities.

10aCarbonyl compounds (organic); Electron microscopy; Fourier-transform spectroscopy; Redox reaction1 aKamble, Sumit, B.;1 aVyas, Praneet, P.1 aJayaram, Radha, V.;1 aRode, Chandrashekhar, V. uhttp://library.ncl.res.in/content/heterogeneously-catalyzed-domino-synthesis-3-indolylquinones-involving-direct-oxidative-c-c