@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: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:000286995800020, title = {Synthesis of tetrahydro-5-azaindoles and 5-azaindoles using pictet-spengler reaction-appreciable difference in products using different acid catalysts}, journal = {Tetrahedron}, volume = {67}, number = {5}, year = {2011}, month = {FEB}, pages = {936-942}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Pictet-Spengler condensation of 2-(aryl)-2-(1H-pyrrol-2-yl)ethanamines using conventional acid catalysts like TMSCl or TFA resulted in the formation of substituted 5-azaindoles involving a tandem one pot four steps reaction sequence. By contrast use of glacial acetic acid furnished the targeted tetrahydro-5-azaindoles in diastereoselective manner. These were readily dehydrogenated to 5-azaindoles. (C) 2010 Elsevier Ltd. All rights reserved.

}, keywords = {2-(Aryl)-2-(1H-pyrrol-2-yl)ethanamines, 4, 7-Disubstituted-5-azaindoles, 7-Disubstituted-tetrahydro-5-azaindoles, Diastereoselective Pictet-Spengler reaction}, issn = {0040-4020}, doi = {10.1016/j.tet.2010.12.003}, author = {Shumaila, Abdullah M. A. and Puranik, Vedavati G. and Kusurkar, Radhika S.} }