@article {49226, title = {Visible-light mediated C-3 amination of quinoxalin-2(1H)-ones via electron donor-acceptor complexation}, journal = {Asian Journal of Organic Chemistry}, volume = {13}, year = {2024}, month = {AUG}, type = {Article}, abstract = {

The formation of carbon-nitrogen bonds holds paramount importance in the realm of synthetic organic chemistry, finding extensive applications in the synthesis of pharmaceuticals, agrochemicals, and organic materials. Herein, we describe a novel EDA complex mediated, metal- and photocatalyst-free, visible-light-initiated direct C-3 amination of biologically important, quinoxalin-2(1H)-one moiety. The key to the success lies in the formation of a photoactivated electron donor-acceptor complex between quinoxalin-2(1H)-one and amine, which undergo subsequent electron transfer reaction to effect the desired transformation. A diverse array of 3-aminoquinoxalin-2(1H)-ones were prepared employing this process and the yields are up to 87\%. This work represents a significant advancement toward a more environmentally friendly and efficient approach, characterized by mild reaction conditions and a high atom economy.

}, keywords = {C-3 amination, Dehydrogenative amination, EDA complex, quinoxalin-2(1H)-ones}, issn = {2193-5807}, doi = {10.1002/ajoc.202400150}, author = {More, Devidas A. and Gayathri, P. R. and Thete, Kishor R. and Muthukrishnan, M.} } @article {49851, title = {Ag(I)-catalyzed heterocyclization/[3+2] cycloaddition of α-alkynylenones with β-enaminones: tandem access to highly substituted cyclopenta[c]furans}, journal = {Journal of Organic Chemistry}, volume = {90}, year = {2025}, month = {SEP }, pages = {12466-12479}, type = {Article}, abstract = {

A robust Ag(I)-catalyzed tandem heterocyclization/[3 + 2] cycloaddition of alpha-alkynylenones with beta-enaminones was developed, enabling efficient synthesis of cyclopenta[c]furans with good yields, operational simplicity, and broad substrate scope. In addition, it also presents an extended methodology to synthesize unsymmetrical tri(hetero)aryl methane having chromone and furan/pyrrole scaffolds by a slight modification of starting materials. Moreover, the synthesized cyclopenta[c]furans exhibit good fluorescence properties with quantum yields ranging from 0.33 to 0.53, as suggested by the photophysical studies.

}, issn = {0022-3263}, doi = {10.1021/acs.joc.5c01707}, author = {Vara, Vijay and Thete, Kishor R. and Panikar, Sera Deepu and Khan, Akram A. and Muthukrishnan, M.} } @article {49399, title = {Manganese-mediated cascade radical oxidative cyclization/1,6-conjugate addition of unsaturated oximes with p-quinone methides: facile access to β,β-diarylmethine substituted isoxazolines}, journal = {Chemistry-An Asian Journal}, volume = {20}, year = {2025}, month = {JAN}, type = {Article}, abstract = {

A simple and efficient strategy for the synthesis of structurally diverse beta,beta-diarylmethine substituted isoxazoline derivatives have been developed. This approach employs a manganese-promoted oxidative cyclization coupled with a 1,6-conjugate addition of unsaturated oximes to p-quinone methides. The key features of this study include the formation of C-O and C-C bonds through intramolecular and intermolecular interactions, facilitated by in situ generated iminoxyl radicals. beta,beta-diarylmethine substituted isoxazolines, bearing a wide range of functional groups, were isolated in high yields.

}, keywords = {p-Quinone methide, diarylmethine substituted isoxazolines, Iminoxy radical, Manganese catalyzed}, issn = {1861-4728}, doi = {10.1002/asia.202401079}, author = {Vara, Vijay and Thete, Kishor R. and Ghotekar, Ganesh S. and Muthukrishnan, M.} } @article {49790, title = {Phosphine-catalyzed nucleophilic ring opening of cyclopropenones with sulfoximines to access N-α,β-unsaturated acyl sulfoximines}, journal = {Journal of Organic Chemistry}, volume = {90}, year = {2025}, month = {AUG}, pages = {10643-10653}, type = {Article}, abstract = {

Herein, we describe the formation of biologically relevant N-alpha,beta-unsaturated acyl sulfoximines via phosphine-catalyzed C-C bond activation of cyclopropenones with weakly nucleophilic sulfoximines. The new process does not require a transition metal or external oxidant and displays high regioselectivity and exclusive E-selectivity. Other salient features of the method are a broad substrate scope, high compatibility with various functional groups, and high atom economy.

}, issn = {0022-3263}, doi = {10.1021/acs.joc.5c00883}, author = {Thete, Kishor R. and Vara, Vijay and Khan, Akram A. and Muthukrishnan, M.} } @article {50022, title = {Radical-promoted cyclization of 3-allyl-2-arylquinazolinones mediated by silver(i) salts to access SCF3/SCN-enriched dihydroisoquinolino[1,2-b]quinazolinones}, journal = {Organic \& Biomolecular Chemistry}, volume = {24}, year = {2026}, month = {FEB}, pages = {1263-1267}, type = {Article}, abstract = {

Herein, we describe an efficient approach for the synthesis of SCF3- and SCN-functionalized polycyclic dihydroisoquinolino[1,2-b]quinazolinones through radical-mediated thio-functionalization of allylic alkenes followed by intramolecular cyclization. The transformation proceeds through sulfur-radical-triggered C-S and C-C bond formation, providing an efficient route to sulfur- and fluorine-enriched polycyclic quinazolinones. Moreover, this strategy offers high atom economy, operational simplicity, and broad substrate compatibility.

}, issn = {1477-0520}, doi = {10.1039/d5ob01755f}, author = {Vara, Vijay and Thete, Kishor R. and Khan, Akram A. and Muthukrishnan, M.} }