@article {42442, title = {Synthesis of functionalized coumarins and quinolinones by NHC-catalyzed annulation of modified enals with heterocyclic C-H acids}, journal = {Journal of Organic Chemistry}, volume = {79}, year = {2014}, month = {APR}, pages = {4245{\textendash}4251}, abstract = {

N-Heterocyclic carbene (NHC) catalyzed lactonization and lactamization of 2-bromoenals with heterocyclic C{\textendash}H acids proceeding via the α,β-unsaturated acyl azolium intermediates is reported. The reaction furnished coumarin- or quinolinone-fused lactone/lactam derivatives. In addition, results of the enantioselective version of this reaction using chiral NHC are presented.

}, doi = {10.1021/jo500693h}, author = {Yetra, Santhivardhana Reddy and Roy, Tony and Bhunia, Anup and Porwal, Digvijay and Biju, Akkattu T.} } @article {42431, title = {Synthesis of 4H-chromenes by an unexpected, K3PO4-mediated intramolecular rauhut{\textendash}currier type reaction}, journal = {Organic \& Biomolecular Chemistry}, volume = {14}, year = {2016}, month = {APR}, pages = {5612-5616}, abstract = {

In an attempt to develop the umpolung of Michael acceptors using chalcones having an enoate moiety under N-heterocyclic carbene (NHC) catalysis, a K3PO4-mediated intramolecular Rauhut{\textendash}Currier type reaction was observed. This C(sp2){\textendash}C(sp2) coupling reaction afforded the biologically important 4H-chromenes in moderate to good yields. It is likely that the enol ether functionality acts as the nucleophilic trigger in this reaction.

}, doi = {10.1039/C6OB00654J}, author = {Bhunia, Anup and Yetra, Santhivardhana Reddy and Gonnade, Rajesh G. and Biju, Akkattu T.} }