@article { ISI:000259104700034, title = {Multi-component carbon-carbon bond forming Mannich reaction catalyzed by yttria-zirconia based Lewis acid}, journal = {Catalysis Communications}, volume = {9}, number = {14}, year = {2008}, month = {AUG}, pages = {2445-2448}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

A direct three component Mannich-type reaction of aldehyde, amine, and ketone (without silyl enolates) were efficiently catalyzed by yttria-zirconia based strong Lewis acid in aqueous acetonitrile. (C) 2008 Elsevier B.V. All rights reserved.

}, keywords = {beta-amino carbonyls, Mannich reaction, multi-component reaction, yttria-zirconia based Lewis acid}, issn = {1566-7367}, doi = {10.1016/j.catcom.2008.06.011}, author = {Ramalingam, S. and Kumar, Pradeep} } @article { ISI:000362919100021, title = {Mild regiospecific alcoholysis and aminolysis of epoxides catalyzed by zirconium(IV) oxynitrate}, journal = {Tetrahedron Letters}, volume = {56}, number = {43}, year = {2015}, month = {OCT}, pages = {5916-5919}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

A regiospecific method for the ring-opening reaction of epoxides by the primary, secondary, tertiary alcohols, and aryl, aliphatic amines has been developed using non-toxic metal nitrate salt as a catalyst. The best results were obtained using zirconium(IV) oxynitrate among the various screened metal nitrate salts. The reported protocol works efficiently for styrene epoxide and aliphatic as well. (C) 2015 Elsevier Ltd. All rights reserved.

}, keywords = {Alcoholysis, Aminolysis, Epoxide, Lewis acid, Zirconia}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2015.09.031}, author = {Shinde, Sandip S. and Said, Madhukar S. and Surwase, Trupti B. and Kumar, Pradeep} } @article { ISI:000362749100016, title = {Modular synthesis of biaryl-substituted phosphine ligands: application in microwave-assisted palladium-catalyzed C-N cross-coupling reactions}, journal = {European Journal of Organic Chemistry}, number = {29}, year = {2015}, month = {OCT}, pages = {6515-6525}, publisher = {WILEY-V C H VERLAG GMBH}, address = {POSTFACH 101161, 69451 WEINHEIM, GERMANY}, abstract = {

Biaryl-substituted monophosphine-based ligands have been synthesized by transition-metal-free ARYNE cross-coupling reaction of aryllithiums with 1,2-dibromobenzene and subsequent regioselective functionalization through bromine-lithium interconversion. These ligands were employed in palladium-catalyzed C-N bond-forming reactions. The reaction was found to be general with wide substrate applicability. A wide variety of both primary and secondary amines were successfully coupled with an array of differently substituted halobenzenes under microwave irradiation to give the expected products in good to excellent yields. A number of biaryl-substituted phosphine ligands screened for the coupling reaction showed that steric bulk and the electronic properties of substituents on phosphorus play a crucial role in governing the catalytic activity of C-N cross-coupling reactions.

}, keywords = {Biaryls, Cross-coupling, Homogeneous catalysis, Microwave chemistry, Palladium, Phosphines, synthetic methods}, issn = {1434-193X}, doi = {10.1002/ejoc.201500962}, author = {Singh, Chandani and Rathod, Jayant and Jha, Vishwajeet and Panossian, Armen and Kumar, Pradeep and Leroux, Frederic R.} } @article {47588, title = {Metal-free, Tf2NH-catalyzed 1, 6-conjugate addition of imidazopyridine to para-quinone methides: easy access to C3-functionalized triarylmethane imidazopyridine}, journal = {Tetrahedron}, volume = {101}, year = {2021}, month = {NOV}, pages = {132510}, type = {Article}, abstract = {An inexpensive and commercially available Tf2NH-catalyzed 1,6-conjugate addition of imidazopyridine (IMPY) heterocycles to para-quinone methides (p-QMs) is reported. The present transformation provides a diverse class of C3-functionalized triarylmethanes heterocyclic derivatives of imidazopyridine. These metal-free transformations provided a very broad substrate scope of conjugate addition product with a high yield up to 97\% within a short duration. (C) 2021 Elsevier Ltd. All rights reserved.}, keywords = {1, 6-Conjugate addition, Bronsted acid, C3-functionalization, Imidazopyridine, para-Quinone methide}, issn = {0040-4020}, doi = {10.1016/j.tet.2021.132510}, author = {Khonde, Nilesh S. and Said, Madhukar S. and Sabane, Jagjivan K. and Gajbhiye, Jayant M. and Kumar, Pradeep} }