@article { ISI:000248002800006, title = {Unprecedented two-dimensional polymeric [Zn(OOC-C6H4-COO)(2)](2_)(n)[+H3N-(CH2)(3)-NH(3])(+)n system bearing one-dimensional chain of zinc(II) bis(phthalate) dianions held by propane-1,3-diammonium cations: crystal structure, thermal and fluorescent pr}, journal = {Solid State Sciences}, volume = {9}, number = {6}, year = {2007}, month = {JUN}, pages = {491-495}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

A novel zinc(II) phthalate compound, [Zn{C6H4(COO)(2)}(2)](n)(2-)[NH3-(CH2)(3)-NH3](n)(2+), 1 Which contains four different phthalate moieties coordinated to the Zn(II) ion through one each of their carboxyl ate moieties in a eta(1)-form and each phthalate moiety acting as a bridging unit with an overall tetrahedral geometry around the metal ion has been prepared and structurally characterized. The structure is unique in the sense that the dianionic moieties [Zn{C6H4(COO)(2)}(2)](2-) form an infinite one-dimensional network composed of 14-membered cyclic units interconnected in a way that they are disposed alternatively in almost perpendicular planes. The dicationic [NH3-(CH2)(3)-NH3](2+) units are seen to hold these one-dimensional chains by strong coulombic and hydrogen bond interaction, resulting in an infinite two-dimensional layered structure of 1. The compound is thermally stable up to 250 degrees C. Above this temperature it loses one equivalent of phthalate moiety along with the diammonium unit to yield Zn(II) phthalate. The thermodynamic and kinetic parameters associated with this process could be evaluated using Coats-Redfern equation which shows the activation energy Ea for the process as 305.0 kJ mol(-1), the frequency factor A as 1.49 x 10(11) s(-1) and the entropy change Delta S as -35.90 JK(-1) mol(-1). Fluorescent emission properties of 1 was studied by exciting the compound at 380 nm and also at 322 nm which were found to be the two lambda(max) corresponding to absorptions of the molecule. Interestingly, the compound gave same type of emission spectra showing a maximum around 444 nm on exciting at these two different wavelengths, indicating that the molecule comes to the first excited state from the higher excited state by a fast non-radiative process before it exhibits singlet emission to come to the ground state. (C) 2007 Elsevier Masson SAS. All rights reserved.

}, keywords = {1, 3-diammonium, cyclic chain, fluorescent emission, layered structure, propane, zinc(II) bis(phthalate) dianion, zinc-phthatate}, issn = {1293-2558}, doi = {10.1016/j.solidstatesciences.2007.04.009}, author = {Padmanabhan, A. and Joseph, K. C. and Puranik, Vedavati G. and Huang, Xiaoying and Li, Jing} } @article { ISI:000259161600016, title = {Convenient access to 1, 3,4-trisubstituted pyrazoles carrying 5-nitrothiophene moiety via 1,3-dipolar cycloaddition of sydnones with acetylenic ketones and their antimicrobial evaluation}, journal = {European Journal of Medicinal Chemistry}, volume = {43}, number = {8}, year = {2008}, month = {AUG}, pages = {1715-1720}, publisher = {ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER}, type = {Article}, address = {23 RUE LINOIS, 75724 PARIS, FRANCE}, abstract = {

Novel 1-aryl-3-(5-nitro-2-thienyl)-4-aroyl-pyrazoles 7 have been synthesized by the 1,3-dipolar cycloaddition of 3-arylsydnones 3 with 1-aryl-3-(5-nitro-2-thienyl)-2-propyn- 1-ones 6. The newly synthesized compounds were well characterized by elemental analysis, IR, (1)H NMR and mass spectral studies. They were also screened for their antibacterial and antifungal activities against a variety of microorganisms and the results of such studies have been discussed in this article. (c) 2007 Elsevier Masson SAS. All fights reserved.

}, keywords = {1, 3-dipolar cycloaddition, 5-nitrothiophene, acetylenic ketone, Antibacterial, antifungal, Pyrazole, sydnone}, issn = {0223-5234}, doi = {10.1016/j.ejmech.2007.08.002}, author = {Rai, N. Satheesha and Kalluraya, Balakrishna and Lingappa, B. and Shenoy, Shaliny and Puranik, Vedavati G.} } @article { ISI:000253620600008, title = {Use of the pictet-spengler reaction for the synthesis of 1,4-disubstituted-1,2,3,4-tetrahydro-beta-carbolines and 1,4-disubstituted-beta-carbolines: formation of gamma-carbolines}, journal = {Tetrahedron}, volume = {64}, number = {8}, year = {2008}, month = {FEB}, pages = {1654-1662}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Microwave-assisted conjugate addition of indole on nitro-olefins furnished nitro compounds, which were reduced to tryptamines. Further, by using Pictet-Spengler condensation, new 1,4-disubstituted-1,2,3,4-tetrahydro-beta-carbolines were synthesized in diastereoselective manner. Dehydrogenation of the tetrahydro-beta-carbolines produced new 1,4-disubstituted-beta-carbolines. As a new observation, in some of the cases, Pictet-Spengler condensation and dehydrogenation gave two products, namely 1,4-disubstituted-beta-carbolines and 1,4-disubstituted-gamma-carbolines. A mechanism is proposed for this observation. (C) 2007 Elsevier Ltd. All rights reserved.

}, keywords = {1, 2, 3, 4-Disubstituted-1, 4-disubstituted-beta-carboline, 4-disubstituted-gamma-carboline, 4-tetrahydro-beta-carboline, 4-tetrahydro-gamma-carboline, Pictet-Spengler reaction}, issn = {0040-4020}, doi = {10.1016/j.tet.2007.12.008}, author = {Kusurkar, Radhika S. and Alkobati, Nabil A. H. and Gokule, Anita S. and Puranik, Vedavati G.} } @article { ISI:000269337500015, title = {Highly diastereoselective 1,3-dipolar cycloaddition of a D-galactose-derived nitrone with dimethyl maleate: synthesis of polyhydroxylated perhydroazaazulenes}, journal = {Synlett}, number = {12}, year = {2009}, month = {JUL}, pages = {1959-1963}, publisher = {GEORG THIEME VERLAG KG}, address = {RUDIGERSTR 14, D-70469 STUTTGART, GERMANY}, abstract = {

An intermolecular 1,3-dipolar cycloaddition of a D-galactose-derived nitrone with dimethyl maleate was found to be perfectly diastereoselective at the nitrone carbon to give exclusive formation of isoxazolidine. The N-O bond reductive cleavage in isoxazolidine followed by lactam reduction afforded a pyrrolidine ring skeleton with sugar appendage that on acetonide cleavage and reductive amino-cyclization gave hitherto unknown hydroxymethyl-substituted hexa- and pentahydroxy perhydroazaazulenes.

}, keywords = {1, 3-dipolar nitrone olefin cycloaddition (DNOC), diastereoselectivity, Iminosugars, inhibitors, nitrone}, issn = {0936-5214}, doi = {10.1055/s-0029-1217541}, author = {Bande, Omprakash P. and Jadhav, Vrushali H. and Puranik, Vedavati G. and Dhavale, Dilip D.} } @article { ISI:000290685100004, title = {Diastereoselective synthesis of 1,1,4-trisubstituted-2,3,4,9-tetrahydrospiro-beta-carbolines via glacial acetic acid catalyzed pictet - spengler reaction}, journal = {Arkivoc}, number = {2}, year = {2011}, month = {OCT}, pages = {41-56}, publisher = {ARKAT USA INC}, address = {C/O ALAN R KATRITZKY, UNIV FLORIDA, DEPT CHEMISTRY, PO BOX 117200, GAINESVILLE, FL 32611 USA}, abstract = {

The Pictet-Spengler reaction of substituted tryptamines with cyclic ketones using glacial acetic acid afforded only one diastereomer of unreported 1,1,4-trisubstituted-2,3,4,9-tetrahydrospiro-beta-carbolines. The stereoselectivity in the reaction has been demonstrated using unsymmetrical ketones and single-crystal X-ray analysis of one of the spiro products in the form of base, its sulfate and hydrochloride salts, which indicated the formation of only the R, R diastereomer.

}, keywords = {1, 3, 4, 4-Trisubstituted-2, 9-tetrahydrospiro-beta-carbolines, beta-substituted tryptamine, Diastereoselective Pictet-Spengler reaction, Glacial acetic acid}, issn = {1551-7004}, author = {Shumaila, Abdullah M. A. and Puranik, Vedavati G. and Kusurkar, Radhika S.} } @article { ISI:000308628900033, title = {New synthetic route for 1,2-diketo compounds using unexpected C-C bond cleavage by PCC}, journal = {Tetrahedron Letters}, volume = {53}, number = {39}, year = {2012}, month = {SEP}, pages = {5327-5330}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

An efficient method has been established for the preparation of 1,2-diketones by unexpected C-C bond cleavage in 4-keto-2-hydroxy esters using pyridiniumchlorochromate (PCC). (c) 2012 Elsevier Ltd. All rights reserved.

}, keywords = {1, 2-Diketones, C-C bond cleavage, PCC}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2012.07.095}, author = {Bhosale, Shrikar M. and Momin, Aadil A. and Gawade, Rupesh L. and Puranik, Vedavati G. and Kusurkar, Radhika S.} }