@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:000290602100011, title = {Diastereoselective synthesis of tetrasubstituted-octahydro-3,6-diazacarbazoles and tetrasubstituted-3,6-diazacarbazoles via double Pictet-Spengler reaction}, journal = {Tetrahedron Letters}, volume = {52}, number = {21}, year = {2011}, month = {MAY}, pages = {2661-2663}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Pictet-Spengler condensation of 2,5-bis(2-phenyl-1-aminoethyl)pyrrole using glacial acetic acid afforded only one diastereomer of unreported tetrasubstituted-octahydro-3,6-diazacarbazoles. These were readily dehydrogenated to tetrasubstituted-3,6-diazacarbazoles. The stereoselectivity in the Pictet-Spengler reaction has been demonstrated using single crystal X-ray analysis. (C) 2011 Elsevier Ltd. All rights reserved.

}, keywords = {2, 5-Bis(2-phenyl-1-aminoethyl)pyrrole, 6-diazacarbazoles, Diasteroselective Pictet-Spengler reaction, Glacial acetic acid, Tetrasubstituted-3, Tetrasubstituted-octahydro-3}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2011.03.060}, author = {Shumaila, Abdullah M. A. and Puranik, Vedavati G. and Kusurkar, Radhika S.} } @article { ISI:000330147900013, title = {Synthesis, characterization and molecular structures of homologated analogs of 2-bromo-3-(n-alkylamino)-1,4-napthoquinone}, journal = {Journal of Molecular Structure}, volume = {1056}, year = {2014}, month = {JAN}, pages = {97-103}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Four analogues of 2-bromo-3-(n-alkylamino)-1,4-napthoquinone (where n-alkyl is methyl in L-1Br, ethyl in L-2Br, propyl in L-3Br and butyl in L-4Br) are synthesized and characterized. A reaction mechanism is proposed for the formation of L-1 Br to L-4Br from the starting material 2,3-dibromo-1,4-naphthoquinone. The v(N-H) frequency in the FT-IR spectra is affected by the intramolecular hydrogen bonding in L-1Br to L-4Br and is observed similar to 3267 cm(-1) in L-2Br. A shift of similar to 25 cm(-1) is observed in the v(C-Br) frequency in all the compounds as compared to 2,3-dibromo-1,4-naphthoquinone (627 cm(-1)). A broad charge transfer band is observed between 400 and 600 nm in the UV-Vis spectra, which imparts red colour to all the compounds. Molecular structures of L-2Br and L-3Br were studied by single crystal X-ray diffraction studies. Molecules of L-2Br crystallize in Pca2(1), whereas the molecule L-3Br crystallizes in the P-1 space group. Molecules of L-2Br forms a polymeric chain through N-H...O interaction and forms beautiful butterfly like arrangement of molecules when viewed down the {\textquoteleft}a{\textquoteright} axis. Ladder like polymeric chain of molecules is observed in L-3Br via C-H...O and N-H...O interactions. Every alternating neighbouring chains of L-3Br, show pi-pi stacking interactions between the quinonoid rings of the molecules, however this interaction is not observed in L-2Br. (C) 2013 Elsevier B.V. All rights reserved.

}, keywords = {2, 3-Dibromo-1, 4-naphthoquinone, Aminonaphthoquinone, hydrogen bonding, Michael addition, pi-pi stacking}, issn = {0022-2860}, doi = {10.1016/j.molstruc.2013.10.016}, author = {Salunke-Gawali, Sunita and Pawar, Omkar and Nikalje, Milind and Patil, Rishikesh and Weyhermueller, Thomas and Puranik, Vedavati G. and Konkimalla, V. Badireenath} } @article {46106, title = {Amphiphilic polypyridyl ruthenium complexes: synthesis, characterization and aggregation studies}, journal = {Polyhedron}, volume = {164}, year = {2019}, month = {MAY }, pages = {96-107}, type = {Article}, abstract = {

{Synthesis and characterization of five amphiphilic ruthenium(11) complexes of the type [Ru(Cn)(3)]center dot(PF6)(2) (Cn = 4,4{\textquoteright}-dialkyl-2,2{\textquoteright}-bipyridine

}, keywords = {2, 2 {\textquoteleft}-bipyridine, Aggregation, Amphiphilic ligand, Metallosurfactant, Ruthenium complexes}, issn = {0277-5387}, doi = {10.1016/j.poly.2019.02.035}, author = {Bhand, Sujit and Lande, Dipali N. and Pereira, Eulalia and Gejji, Shridhar P. and Weyhermueller, Thomas and Chakravarty, Debamitra and Puranik, Vedavati G. and Salunke-Gawali, Sunita} }