@article {46021,
	title = {N-Heterocyclic carbene-catalyzed umpolung of imines for the enantioselective synthesis of dihydroquinoxalines},
	journal = {ACS Catalysis},
	volume = {9},
	year = {2019},
	month = {MAY},
	pages = {4065-4071},
	type = {Article},
	abstract = {<p>N-heterocyclic carbene (NHC) organocatalysis is widely employed for the umpolung of aldehydes and recently to the umpolung of Michael acceptors and aldimines. Described herein is the NHC-organocatalyzed umpolung of aldimines for the enantioselective synthesis of nitrogen heterocycles. The bisimines generated from the condensation of 1,2-phenylenediamines and salicylaldehydes undergo intramolecular cyclization in the presence of a chiral NHC catalyst, resulting in the formation of dihydroquinoxalines in moderate to good yields and er values. Detailed DFT studies shed light on the role of -OH groups in stabilizing the initially generated aza-Breslow intermediates via intramolecular hydrogen bonds. Preliminary photophysical studies on the synthesized dihydroquinoxalines revealed that these molecules can be used for the sensing of various acids and bases.</p>},
	keywords = {dihydroquinoxalines, imines, N-heterocyclic carbenes, organocatalysis, umpolung},
	issn = {2155-5435},
	doi = {10.1021/acscatal.9b00737},
	author = {Das, Tamal Kanti and Ghosh, Avik and Balanna, Kuruva and Behera, Pradipta and Gonnade, Rajesh G. and Marelli, Udaya Kiran and Das, Abhijit Kumar and Biju, Akkattu T.}
}
@article {48752,
	title = {N-heterocyclic carbene-catalyzed atroposelective synthesis of N-N axially chiral 3-amino quinazolinones},
	journal = {ACS Catalysis},
	volume = {13},
	year = {2023},
	month = {JUN },
	pages = {8752-8759},
	type = {Article},
	abstract = {<p>
	Although the atroposelective synthesisof biaryls and related compoundsbearing axially chiral C-C bonds is well-known, the synthesisof axially chiral C-N bond-containing compounds is relativelyless explored, and the construction of axially chiral N-N bondshas received only scant attention. Demonstrated herein is the N-heterocycliccarbene (NHC)-catalyzed selective amidation reaction, leading to theatroposelective synthesis of N-N axially chiral 3-amino quinazolinones.The NHC-catalyzed reaction of quinazolinones containing a free N-Hmoiety with \&amp; alpha;,\&amp; beta;-unsaturated aldehydes under oxidativeconditions furnished the atropisomeric quinazolinone derivatives undermild conditions and broad scope. Preliminary studies on experimentaland density functional theory-based N-N rotational barrierdetermination are also presented.</p>
},
	keywords = {amino quinazolinones, asymmetriccatalysis, axial chirality, N-heterocycliccarbenes, organocatalysis},
	issn = {2155-5435},
	doi = {10.1021/acscatal.3c01709},
	author = {Balanna, Kuruva and Barik, Soumen and Barik, Shilpa and Shee, Sayan and Manoj, Niket and Gonnade, Rajesh G. and Biju, Akkattu T.}
}
