@article { ISI:000255086600041, title = {Highly active nanostructured Co3O4 catalyst with tunable selectivity for liquid phase air oxidation of p-cresol}, journal = {Chemistry Letters}, volume = {37}, number = {3}, year = {2008}, month = {MAR}, pages = {310-311}, publisher = {CHEMICAL SOC JAPAN}, type = {Article}, address = {1-5 KANDA-SURUGADAI CHIYODA-KU, TOKYO, 101-8307, JAPAN}, abstract = {

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.

}, issn = {0366-7022}, doi = {10.1246/cl.2008.310}, author = {Kshirsagar, Vikas S. and Vijayanand, Subramanian and Potdar, Hari S. and Joy, Pattayil Alias and Patil, Kashinath R. and Rode, Chandrashekhar V.} } @article { ISI:000271103500011, title = {Heterogeneous cobalt-saponite catalyst for liquid phase air oxidation of p-cresol}, journal = {Industrial \& Engineering Chemistry Research}, volume = {48}, number = {21}, year = {2009}, month = {NOV}, pages = {9423-9427}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

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.

}, issn = {0888-5885}, doi = {10.1021/ie801941e}, author = {Kshirsagar, Vikas S. and Garade, Ajit C. and Patil, Kashinath R. and Jha, Ratnesh Kumar and Rode, Chandrashekhar V.} } @article { ISI:000275524800024, title = {Hydroxyalkylation of p-Cresol to 2,2 {\textquoteleft}-methylenebis(4-methylphenol) using Sn/Si-MCM-41 catalysts}, journal = {Chemistry Letters}, volume = {39}, number = {2}, year = {2010}, month = {FEB}, pages = {126-127}, publisher = {CHEMICAL SOC JAPAN}, address = {1-5 KANDA-SURUGADAI CHIYODA-KU, TOKYO, 101-8307, JAPAN}, abstract = {

Sn/Si-MCM-41 has exhibited an excellent catalytic activity [70\% product yield with 88\% selectivity to 2,2{\textquoteright}-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.

}, issn = {0366-7022}, doi = {10.1246/cl.2010.126}, author = {Garade, Ajit C. and Niphadkar, Prashant S. and Joshi, Praphulla N. and Rode, Chandrashekhar V.} } @article { ISI:000316583700015, title = {Heterogeneous Co3O4 catalyst for selective oxidation of aqueous veratryl alcohol using molecular oxygen}, journal = {Catalysis Communications}, volume = {33}, year = {2013}, month = {MAR}, pages = {66-69}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

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.

}, keywords = {Co3O4, Cyclic voltammogram, Liquid phase oxidation, Molecular oxygen, Veratryl alcohol, XPS}, issn = {1566-7367}, doi = {10.1016/j.catcom.2012.12.015}, author = {Mate, Vivek R. and Shirai, Masayuki and Rode, Chandrashekhar V.} } @article { ISI:000326900600016, title = {Highly efficient povidone-phosphotungstic acid catalyst for the tandem acetalization of aldehydes to bis- and tris(indolyl)methanes}, journal = {ChemPlusChem}, volume = {78}, number = {11}, year = {2013}, month = {NOV}, pages = {1393-1399}, publisher = {WILEY-V C H VERLAG GMBH}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

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.

}, keywords = {acetals, Acidity, aldehydes, heterogeneous catalysis, heteropoly acids}, issn = {2192-6506}, doi = {10.1002/cplu.201300248}, author = {Kamble, Sumit B. and Swami, Rameshwar K. and Sakate, Sachin S. and Rode, Chandrashekhar V.} } @article { ISI:000323110700013, title = {Highly selective liquid-phase aerobic oxidation of vanillyl alcohol to vanillin on cobalt oxide (Co3O4) nanoparticles}, journal = {New Journal of Chemistry}, volume = {37}, number = {9}, year = {2013}, month = {JUN}, pages = {2669-2674}, publisher = {ROYAL SOC CHEMISTRY}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

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.

}, issn = {1144-0546}, doi = {10.1039/c3nj00508a}, author = {Jha, Ajay and Rode, Chandrashekhar V.} } @article { ISI:000358237400020, title = {Highly efficient triphenyl(3-sulfopropyl)phosphonium functionalized phosphotungstic acid on silica as a solid acid catalyst for selective mono-allylation of acetals}, journal = {Catalysis Science \& Technology}, volume = {5}, number = {8}, year = {2015}, month = {MAY}, pages = {4039-4047}, publisher = {ROYAL SOC CHEMISTRY}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

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.

}, issn = {2044-4753}, doi = {10.1039/c5cy00531k}, author = {Kamble, Sumit B. and Shinde, Suhas H. and Rode, Chandrashekhar V.} } @article { ISI:000353641800022, title = {Hydrogen production by the water-gas shift reaction using CuNi/Fe2O3 catalyst}, journal = {Catalysis Science \& Technology}, volume = {5}, number = {5}, year = {2015}, month = {FEB}, pages = {2752-2760}, publisher = {ROYAL SOC CHEMISTRY}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

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.

}, issn = {2044-4753}, doi = {10.1039/c5cy00173k}, author = {Jha, Ajay and Jeong, Dae-Woon and Shim, Jae-Oh and Jang, Won-Jun and Lee, Yeol-Lim and Rode, Chandrashekhar V. and Roh, Hyun-Seog} } @article {43411, title = {Highly selective direct azidation of alcohols over a heterogeneous povidone-phosphotungstic solid acid catalyst}, journal = {New Journal of Chemistry}, volume = {40}, year = {2016}, month = {DEC}, pages = {10240-10245}, abstract = {A 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.}, doi = {10.1039/c6nj02500e}, author = {Kamble, Sumit and More, Sagar and Rode, Chandrashekhar V.} } @article {43948, title = {Heterogeneously catalyzed domino synthesis of 3-indolylquinones involving direct oxidative C-C coupling of hydroquinones and indoles}, journal = {ACS Omega}, volume = {2}, year = {2017}, month = {MAY}, chapter = {2238-2247}, abstract = {
Abstract Image

A domino synthesis of 3-indolylquinones was achieved successfully via direct oxidative C{\textendash}C coupling of hydroquinones with indoles over Ag2O and Fe3O4/povidone{\textendash}phosphotungstic acid (PVP{\textendash}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{\textendash}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{\textendash}97\%) of 3-indolylquinones. Fe3O4/PVP{\textendash}PWA was separated magnetically, whereas simple filtration could separate Ag2O, both of which could be recycled several times without losing their activities.

}, keywords = {Carbonyl compounds (organic); Electron microscopy; Fourier-transform spectroscopy; Redox reaction}, doi = {10.1021/acsomega.7b00201}, author = {Kamble, Sumit B.; and Vyas, Praneet P. and Jayaram, Radha V.; and Rode, Chandrashekhar V.} }