@article { ISI:000242873400035, title = {Potassium phosphate or silica sulfuric acid catalyzed conjugate addition of thiols to alpha,beta-unsaturated ketones at room temperature under solvent-free conditions}, journal = {Tetrahedron Letters}, volume = {47}, number = {52}, year = {2006}, month = {DEC}, pages = {9325-9328}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Potassium phosphate and silica sulfuric acid have been found to be useful and highly efficient catalysts for conjugate addition of thiols to alpha,beta-unsaturated ketones under solvent-free conditions, at room temperature. Silica sulfuric acid (SSA) was found to be suitable for electron-deficient enones while potassium phosphate was found to effect thia-Michael addition with both, electron-deficient as well as electron-rich conjugated ketones. (c) 2006 Elsevier Ltd. All rights reserved.

}, keywords = {alpha, beta-unsaturated ketones, chalcones, conjugated enones, Michael addition, Potassium phosphate, silica sulfuric acid, thiols}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2006.10.114}, author = {Pore, D. M. and Soudagar, M. S. and Desai, Uday V. and Thopate, T. S. and Wadagaonkar, P. P.} } @article { ISI:000309634900001, title = {Practical and highly efficient protocol for multicomponent synthesis of beta-phosphonomalononitriles and 2-amino-4H-chromen-4-yl phosphonates using diethylamine as a novel organocatalyst}, journal = {Comptes Rendus Chimie}, volume = {15}, number = {9}, year = {2012}, month = {SEP}, pages = {745-752}, publisher = {ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER}, address = {23 RUE LINOIS, 75724 PARIS, FRANCE}, abstract = {

Diethylamine has been demonstrated for the first time to be a highly efficient organocatalyst in the solvent-free synthesis of beta-phosphonomalononitriles by a three component condensation of aldehyde, malononitrile and dialkyl phosphite at ambient temperature. The applicability of the same catalyst in the synthesis of diethyl (2-amino-3-cyano-chromene-4-yl) phosphonic acid esters has also been described. (c) 2012 Published by Elsevier Masson SAS on behalf of Academie des sciences.

}, keywords = {2-amino-4H-chromenes, beta-phosphonomalononitriles, diethylamine, multicomponent reactions, organocatalyst, Phospha-Michael reaction}, issn = {1631-0748}, doi = {10.1016/j.crci.2012.07.001}, author = {Kulkarni, M. A. and Pandurangi, V. R. and Desai, Uday V. and Wadgaonkar, P. P.} } @article { ISI:000377425900059, title = {Problem solving and environmentally benign approach toward diversity oriented synthesis of novel 2-amino-3-phenyl (or Alkyl) sulfonyl-4H-chromenes at ambient temperature}, journal = {ACS Sustainable Chemistry \& Engineering}, volume = {4}, number = {6}, year = {2016}, month = {JUN}, pages = {3450-3464}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

A problem solving, environmentally benign, and diversity oriented protocol has been described for multi component synthesis of medicinally privileged 2-amino-3-phenyl (or methyl) sulfonyl-4H-chromenes by one-pot, three component condensation among aldehydes, phenyl (or methyl) sulphonyl acetonitrile, and alpha-naphthol, 3-dimethylamino phenol, 4-hydroxy-N-methyl-quinoline-2-one as well as 4-hydroxycarbazole, using diethylamine as an efficient organo catalyst. The catalyst employed is commercially available, inexpensive, and nontoxic. Ambient reaction conditions, very high yields, wide scope, and avoidance of conventional isolation as well as chromatographic purification have improved the practical utility of this protocol manifold.

}, keywords = {2-Amino-3-methylsulfonyl-4H-chromenes, 2-Amino-3-phenylsulfonyl-4H-chromenes, diethylamine, green chemistry, Multicomponent synthesis, organocatalyst}, issn = {2168-0485}, doi = {10.1021/acssuschemeng.6b00484}, author = {Pandit, Kapil S. and Kupwade, Ravindra V. and Chavan, Pramod V. and Desai, Uday V. and Wadgaonkar, Prakash P. and Kodam, Kisan M.} }