@article {43353, title = {Facile synthesis of N-acyl 2-aminobenzothiazoles by NHC-catalyzed direct oxidative amidation of aldehydes}, journal = {Chemical Communications}, volume = {53}, year = {2017}, month = {JAN}, pages = {1478 - 1481}, abstract = {A mild, general, and high yielding synthesis of N-acyl 2-aminobenzothiazoles has been demonstrated by N-heterocyclic carbene (NHC)-organocatalyzed direct amidation of aldehydes with 2-aminobenzothiazoles proceeding via acyl azolium intermediates. The carbene generated from the triazolium salt under oxidative conditions was the key for the success of this reaction. The method was subsequently applied to the synthesis of various biologically important N-acyl 2-aminobenzothiazoles.}, doi = {10.1039/C6CC08640C}, author = {Premaletha, Sethulekshmi and Ghosh, Arghya and Joseph, Sumi and Reddy, Santhi Vardhan and Biju, Akkattu T.} } @article {44644, title = {N-Heterocyclic carbene-catalyzed enantioselective synthesis of spiro-glutarimides via alpha,beta-unsaturated acylazoliums}, journal = {Organic Letters}, volume = {20}, year = {2018}, month = {AUG}, pages = {4499-4503}, abstract = {

NHC-catalyzed enantioselective [3 + 3] spiro-annulation of alpha,beta-unsaturated aldehydes with cyclic beta-ketoamides allowing the preparation of synthetically and biologically important spiro-glutarimide derivatives has been reported. The interception of the ketoamides with catalytically generated chiral alpha,beta-unsaturated acylazoliums proceeds in a Michael addition-intramolecular amidation pathway to deliver the spirocyclic products with good yield, diastereoselectivity, and enantioselectivity.

}, issn = {1523-7060}, doi = {10.1021/acs.orglett.8b01799}, author = {Mondal, Santigopal and Ghosh, Arghya and Mukherjee, Subrata and Biju, Akkattu T.} } @article {44535, title = {N-Heterocyclic carbene-catalyzed michael-michael-lactonization cascade for the enantioselective synthesis of tricyclic delta-lactones}, journal = {Organic Letters}, volume = {20}, year = {2018}, month = {MAY}, pages = {2952-2955}, abstract = {

Enantioselective synthesis of tricyclic delta-lactones with three contiguous stereocenters has been demonstrated by the N-heterocyclic carbene (NHC)-catalyzed functionalization of benzylic C(sp(3))-H bonds. The NHC-catalyzed reaction of enals with dinitrotoluene derivatives under oxidative conditions proceeds via the chiral alpha,beta-unsaturated acylazoliums and produces the delta-lactones in good yields and excellent diastereoselectivity and enantioselectivity. This mild and atom-economic cascade reaction takes place in a Michael/Michael/lactonization sequence and tolerates a broad range of functional groups.

}, issn = {1523-7060}, doi = {10.1021/acs.orglett.8b00998}, author = {Mukherjee, Subrata and Ghosh, Arghya and Marelli, Udaya Kiran and Biju, Akkattu T.} } @article {45507, title = {Synthesis of 2-Aryl naphthoquinones by the cross-dehydrogenative coupling involving an NHC-catalyzed endo-stetter reaction}, journal = {Journal of Organic Chemistry}, volume = {84}, year = {2019}, month = {JAN }, pages = {1103-1110}, type = {Article}, abstract = {

An N-heterocyclic carbene (NHC)-catalyzed intramolecular Stetter reaction proceeding via the endo-fashion was the key step for the transition-metal-free and mild cross-dehydrogenative coupling of 2-cinnamoyl benzal-dehydes allowing for the synthesis of 2-aryl naphthoquinones. In this transformation, the carbene generated from the triazolium salt using Na2CO3 catalyzes the intramolecular Stetter reaction, which was followed by air oxidation to reinstall the C-C double bond.

}, issn = {0022-3263}, doi = {10.1021/acs.joc.8b02931}, author = {Ghosh, Arghya and Patra, Atanu and Mukherjee, Subrata and Biju, Akkattu T.} } @article {47626, title = {Enantioselective synthesis of 5,6-dihydroindolizines by N-heterocyclic carbene (NHC)-catalyzed core-structure-inspired strategy of azolium-enolate cascade}, journal = {Organic Letters}, volume = {23}, year = {2021}, month = {JUL }, pages = {5223-5228}, type = {Article}, abstract = {The core-structure motivated design has allowed the enantioselective synthesis of 5,6-dihydroindolizines via N-heterocyclic carbene (NHC) catalysis. The NHC-catalyzed reaction of alpha,beta-unsaturated aldehydes with the suitably substituted pyrrole derivatives proceed via the initial generation of alpha,beta-unsaturated acylazoliums from enals, and enolates from pyrroles and the reaction culminated in an efficient cascade process involving the Michael-aldol-lactonization-decarboxylation sequence to afford the products in reasonable yields and high selectivities. The method is further extended to the construction of spirocyclic 5,6-dihydroindolizines.}, issn = {1523-7060}, doi = {10.1021/acs.orglett.1c01761}, author = {Ghosh, Arghya and Shee, Sayan and Barik, Shilpa and Gonnade, Rajesh G. and Biju, Akkattu T.} }