@article {45880,
	title = {Enantioselective synthesis of functionalized pyrazoles by NHC-catalyzed reaction of pyrazolones with alpha,beta-unsaturated aldehydes},
	journal = {Organic Letters},
	volume = {17},
	year = {2015},
	month = {MAR},
	pages = {1417-1420},
	type = {Article},
	abstract = {<p>The N-heterocyclic carbene (NHC)-organocatalyzed enantioselective annulation reaction of pyrazolones with alpha,beta-unsaturated aldehydes proceeding via the chiral alpha,beta-unsaturated acyl azolium intermediates under oxidative conditions is presented. The reaction afforded dihydropyranone-fused pyrazoles in moderate to good yields and good er values under operationally simple and base-free conditions.</p>},
	issn = {1523-7060},
	doi = {10.1021/acs.orglett.5b00293},
	author = {Yetra, Santhivardhana Reddy and Mondal, Santigopal and Suresh, Eringathodi and Biju, Akkattu T.}
}
@article { ISI:000368065300033,
	title = {Enantioselective synthesis of spirocyclohexadienones by NHC-catalyzed formal [3+3] annulation reaction of enals},
	journal = {Angewandte Chemie-International Edition},
	volume = {55},
	number = {1},
	year = {2016},
	month = {JAN},
	pages = {268-272},
	publisher = {WILEY-V C H VERLAG GMBH},
	address = {POSTFACH 101161, 69451 WEINHEIM, GERMANY},
	abstract = {<p>The enantioselective synthesis of pyrazolone-fused spirocyclohexadienones was demonstrated by the reaction of alpha,beta-unsaturated aldehydes with alpha-arylidene pyrazolinones under oxidative N-heterocyclic carbene (NHC) catalysis. This atom-economic and formal [3+3] annulation reaction proceeds through a vinylogous Michael addition/spiroannulation/dehydrogenation cascade to afford spirocyclic compounds with an all-carbon quaternary stereocenter in moderate to good yields and excellent ee values. Key to the success of the reaction is the cooperative NHC-catalyzed generation of chiral alpha,beta-unsaturated acyl azoliums from enals, and base-mediated tandem generation of dienolate/enolate intermediates from pyrazolinones.</p>},
	keywords = {annulation reactions, asymmetric catalysis, N-heterocyclic carbenes, organocatalysis, spiro compounds},
	issn = {1433-7851},
	doi = {10.1002/anie.201507802},
	author = {Yetra, Santhivardhana Reddy and Mondal, Santigopal and Mukherjee, Subrata and Gonnade, Rajesh G. and Biju, Akkattu T.}
}
@article {43910,
	title = {Enantioselective synthesis of functionalized β-lactones by NHC-catalyzed aldol lactonization of ketoacids},
	journal = {Journal of Organic Chemistry},
	volume = {82},
	year = {2017},
	month = {AUG},
	type = {Article},
	abstract = {N-Heterocyclic carbene (NHC)-catalyzed intramolecular aldol lactonization of readily available ketoacids leading to the enantioselective synthesis of cyclopentane-fused β-lactones is presented. The reaction proceeds via the generation of NHC-bound enolate intermediates formed from the ketoacids in the presence of the peptide coupling reagent HATU and NHC generated from the chiral triazolium salt. The functionalized β-lactones are formed under mild conditions in high yields and enantioselectivities.},
	doi = {10.1021/acs.joc.7b01526},
	author = {Mondal, Santigopal and Mukherjee, Subrata and Das, Tamal Kanti and Gonnade, Rajesh G. and Biju, Akkattu T.}
}
