@article { ISI:000229592000044, title = {Copper- and ligand-free sonogashira reaction catalyzed by Pd(0) nanoparticles at ambient conditions under ultrasound irradiation}, journal = {Journal of Organic Chemistry}, volume = {70}, number = {12}, year = {2005}, month = {JUN}, pages = {4869-4872}, publisher = {AMER CHEMICAL SOC}, type = {Article}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

The Sonogashira reaction proceeds at ambient temperature (30 degrees C) in acetone or room-temperature ionic liquid, 1,3-di-n-butylimidazolium tetrafluoroborate ([bbim]BF4), as solvent under ultrasound irradiation to give enhanced reaction rates, excellent chemoselectivity, and high yields in the absence of a copper cocatalyst and a phosphine ligand. TEM analysis showed the formation of stable, crystalline, and polydispersed Pd(0) nanoparticles as catalyst for the reaction.

}, issn = {0022-3263}, doi = {10.1021/jo0503815}, author = {Gholap, Atul R. and Venkatesan, K. and Pasricha, R. and Daniel, Thomas and Lahoti, Rajgopal J. and Srinivasan, K. V.} } @article { ISI:000227273200009, title = {Novel one-pot synthesis of 2-Aryl-4(3H)-quinazolinones using room temperature ionic liquid as reaction medium as well as promoter}, journal = {Synthetic Communications}, volume = {35}, number = {2}, year = {2005}, month = {JUL}, pages = {231-241}, publisher = {MARCEL DEKKER INC}, type = {Article}, address = {270 MADISON AVE, NEW YORK, NY 10016 USA}, abstract = {

An efficient one-pot synthesis of 2-aryl-4(3H)-quinazolinones from 2-amino benzamides and substituted benzoyl chlorides in a room temperature ionic liquid is described. Compared with the classical reaction conditions, this new synthetic method has the advantages of recyclability of ionic liquid, very good to excellent yields (78-92\%), the absence of hazardous and expensive catalysts, and easy workup procedures giving rise to a process with minimum waste.

}, keywords = {2-amino benzamide, 2-aryl-4(3H)-quinazolinones, benzoyl chlorides, Ionic liquid}, issn = {0039-7911}, doi = {10.1081/SCC-200048433}, author = {Potewar, T. M. and Nadaf, R. N. and Daniel, Thomas and Lahoti, Rajgopal J. and Srinivasan, K. V.} } @article { ISI:000227930800010, title = {Room temperature ionic liquid promoted improved and rapid synthesis of 2,4,5-triaryl imidazoles from aryl aldehydes and 1,2-diketones or alpha-hydroxyketone}, journal = {Tetrahedron}, volume = {61}, number = {14}, year = {2005}, month = {APR}, pages = {3539-3546}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

An improved and rapid one-pot synthesis of 2,4,5-triaryl imidazoles in a room temperature ionic liquid is described, which does not need any added catalyst. Different ionic liquids based on 1-n-butyl and 1,3-di-n-butyl imidazolium salts were screened and their efficacy in terms of acidity and polarity have been correlated with yields and reaction period. The one-pot methodology resulting in excellent isolated yields in short reaction times is characterized by simple work up procedures and efficient recovery and recycling of the ionic liquid, which acts as a promoter. (c) 2005 Elsevier Ltd. All rights reserved.

}, keywords = {1, 2, 2-Diketones, 4, 5-triaryl imidazoles, alpha-hydroxyketone, ammonium acetate, benzaldehydes, ionic liquid (IL)}, issn = {0040-4020}, doi = {10.1016/j.tet.2005.01.116}, author = {Siddiqui, S. A. and Narkhede, U. C. and Palimkar, S. S. and Daniel, Thomas and Lahoti, Rajgopal J. and Srinivasan, K. V.} } @article { ISI:000238963800023, title = {Copper-, ligand- and solvent-free synthesis of ynones by coupling acid chlorides with terminal alkynes}, journal = {Tetrahedron Letters}, volume = {47}, number = {31}, year = {2006}, month = {JUL}, pages = {5527-5530}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

A general and efficient copper-, ligand- and solvent-free synthesis of ynones by coupling of a wide range of acid chlorides with terminal alkynes catalyzed by palladium(II) acetate at room temperature is reported. (c) 2006 Elsevier Ltd. All rights reserved.

}, keywords = {ligandless, neat, ynones}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2006.05.166}, author = {Palimkar, Sanjay S. and Kumar, P. Harish and Jogdand, Nivrutti R. and Daniel, Thomas and Lahoti, Rajgopal J. and Srinivasan, Kumar V.} } @article { ISI:000239179300033, title = {Enantioselective synthesis of (+)-(S,S)-reboxetine}, journal = {Synlett}, number = {11}, year = {2006}, month = {JUL}, pages = {1771-1773}, publisher = {GEORG THIEME VERLAG KG}, type = {Article}, address = {RUDIGERSTR 14, D-70469 STUTTGART, GERMANY}, abstract = {

An efficient enantioselective synthesis leading directly to (+)-(S,S)-reboxetine has been described from commercially available trans-cinnammyl bromide using Sharpless asymmetric dihydroxylation as the key step.

}, keywords = {coupling, Dihydroxylation, Hydrogenation, reboxetine, trans-cinnamyl bromide}, issn = {0936-5214}, doi = {10.1055/s-2006-944210}, author = {Siddiqui, Shafi A. and Narkhede, Umesh C. and Lahoti, Rajgopal J. and Srinivasan, Kumar V.} } @article { ISI:000240554000009, title = {Ionic liquid promoted facile one-pot synthesis of 1-pyridylimidazo[1,5-a]pyridines from dipyridylketone and aryl aldehydes}, journal = {Synthesis-Stuttgart}, number = {17}, year = {2006}, month = {SEP}, pages = {2849-2854}, publisher = {GEORG THIEME VERLAG KG}, type = {Article}, address = {RUDIGERSTR 14, D-70469 STUTTGART, GERMANY}, abstract = {

A highly efficient one-pot methodology has been developed to synthesize a class of substituted 1-pyridylimidazo[ 1,5-a]pyridines, using Bronsted acidic ionic liquid 1-butylimidazolium tetrafluoroborate, [Hbim]BF4 in excellent isolated yields in the absence of any catalyst. The methodology is characterized by simple work-up procedures along with efficient recovery and recycling of the ionic liquid, which acts as a reaction medium as well as a promoter.

}, keywords = {5-a]pyridines, Aldehyde, ammonium acetate, heterocycles, imidazo[1, ionic liquids}, issn = {0039-7881}, doi = {10.1055/s-2006-942522}, author = {Siddiqui, Shafi A. and Potewar, Taterao M. and Lahoti, Rajgopal J. and Srinivasan, Kumar V.} } @article { ISI:000237485300010, title = {Ligand-, copper-, and amine-free one-pot synthesis of 2-substituted indoles via Sonogashira coupling 5-endo-dig cyclization}, journal = {Tetrahedron}, volume = {62}, number = {21}, year = {2006}, month = {MAY}, pages = {5109-5115}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Results of the optimized conditions for the one-pot synthesis of 2-substituted indoles via palladium acetate catalyzed tandem Sonogashira coupling 5-endo-dig cyclization at room temperature under ultrasonic irradiation and standard stirred conditions are described. Electron-donating and electron-withdrawing groups present in both Coupling partners were well tolerated under these mild conditions. A copper-, ligand- and amine-free condition is an important feature of this protocol. Significant enhancement of reaction rates was observed for the reactions employing ultrasonic irradiation. (c) 2006 Elsevier Ltd. All rights reserved.

}, keywords = {5-endo-dig cyclization, Indole, synthesis, Ultrasound}, issn = {0040-4020}, doi = {10.1016/j.tet.2006.03.035}, author = {Palimkar, Sanjay S. and Kumar, P. Harish and Lahoti, Rajgopal J. and Srinivasan, Kumar V.} } @article {Datar, title = {Remarkably rapid regioselective synthesis of beta-enaminones using silica chloride in a heterogeneous as well as an ionic liquid in a homogeneous medium at room temperature}, journal = {Journal of Molecular Catalysis A-Chemical}, volume = {245}, number = {1-2}, year = {2006}, note = {6th International Conference on Solvothermal Reactions, Mysore, INDIA, AUG 24-27, 2004}, month = {FEB}, pages = {37-46}, publisher = {ACADEMIC PRESS INC ELSEVIER SCIENCE}, type = {Article}, address = {525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA}, abstract = {

{Silica chloride as a heterogeneous catalyst has been used for the regioselective synthesis of P-amino-a,P unsaturated esters and ketones. Similar regioselective synthesis was also performed using an ionic liquid 1-n-butyl imidazolium tetrafluoroborate [

}, keywords = {direct oxidation of H-2 to H2O2, H2O2 decomposition, H2O2 hydrogenation, Promoting action of chloride or bromide anions, supported Pd catalysts}, issn = {0021-9517}, doi = {10.1016/j.molcata.2005.09.021}, author = {Gholap, Atul R. and Chakor, N. S. and Daniel, Thomas and Lahoti, Rajgopal J. and Srinivasan, K. V.} } @article { ISI:000244119800006, title = {Novel one-pot three-component synthesis of 2,4-disubstituted-3H-benzo[b][1,4]diazepines in water}, journal = {Green Chemistry}, volume = {9}, number = {2}, year = {2007}, month = {NOV}, pages = {146-152}, publisher = {ROYAL SOC CHEMISTRY}, type = {Article}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

A novel green and efficient one-pot three-component synthesis of 2,4-disubstituted-3H-benzo[b][1,4]diazepines in excellent isolated yields has been reported. The methodology initially involves the formation of ynones via coupling of a wide range of acid chlorides with terminal alkynes catalysed by Pd(OAc)(2) under copper-, ligand- and solvent-free conditions in just 10 min at rt followed by the Michael addition and cyclocondensation of o-phenylenediamines added in situ using water as a solvent at reflux temprature. In addition, the structure of the benzodiazepine was confirmed to be the diimino molecule and not the enamine by X-ray crystallographic analysis of the benzodiazepine 4b. The methodology is suitable for the operation in combi-chem mode to generate libraries of a diverse array of benzodiazepines. The methodology has been successful in achieving the twin green chemistry objectives of a solvent and ligand free operation and the use of water as a non-hazardous, inexpensive and readily available solvent in the sequential reaction steps performed in situ, thus combining the features of both economic and environmental advantages.

}, issn = {1463-9262}, doi = {10.1039/b610523h}, author = {Palimkar, Sanjay S. and Lahoti, Rajgopal J. and Srinivasan, Kumar V.} } @article { ISI:000254443900045, title = {Efficient synthesis of 1,8-dioxo-octahydro-xanthene derivatives promoted by a room temperature ionic liquid at ambient conditions under ultrasound irradiation}, journal = {Ultrasonics Sonochemistry}, volume = {15}, number = {4}, year = {2008}, month = {APR}, pages = {548-553}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

The condensation reaction involving an aldehyde and diketone was efficiently promoted by the Ionic liquid, [Hbim]BF(4) (IL) as a reaction medium with methanol as co-solvent at ambient temperature under ultrasonic irradiation to afford the corresponding 1,8-dioxo-octahydroxantliene (xanthene) derivatives in excellent yields. The advantages of this method include among others the use of a recyclable, non-volatile ionic liquid, which promotes this protocol under ambient temperature without the requirement of ally added catalyst. The reaction times and yields are compared with p-TSA catalyzed synthesis of xanthenes under thermal conditions, which is also reported for the first time under our reaction conditions. (c) 2007 Elsevier B.V. All rights reserved.

}, keywords = {aldehydes, ambient conditions, Bronsted acidity, dimedone, Ionic liquid, Ultrasound, Xanthenes}, issn = {1350-4177}, doi = {10.1016/j.ultsonch.2007.06.001}, author = {Venkatesan, K. and Pujari, Suresh S. and Lahoti, Rajgopal J. and Srinivasan, K. V.} }