Copper(i)-Y zeolite catalyzed N-sulfonylketenimine mediated annulation of hydroxynaphthoquinones: syntheses of naphtho[2,1-b]furan-2,5-diones and benzo[de]chromene-2,6-diones.
An efficient one pot synthesis for the construction of novel naphtho[2,1-b]furan-2,5-diones and benzo[de]chromene-2,6-diones using copper(i)-Y zeolite catalyzed reaction of N-sulfonylketenimine with 2-hydroxy-1,4-naphthoquinone and 5-hydroxy-1,4-naphthoquinone followed by the elimination of p-toluenesulfonamide is reported. The intermediate N-sulfonylketenimine, generated by (3+2) cycloaddition/ring-opening reaction/retro-Wolff rearrangement, cascade, and annulation, promotes the reaction involving the inter- and intramolecular nucleophilic addition/dehydration followed by hydrolysis and elimination of p-toluenesulfonamide to afford the target products in good yield.
School of Chemistry, Madurai Kamaraj University, Madurai - 625 021, India.
Devenderan
D
Ramanathan
School of Chemistry, Madurai Kamaraj University, Madurai - 625 021, India.
Kayambu
K
Namitharan
School of Chemistry, Madurai Kamaraj University, Madurai - 625 021, India and Centre for Green Chemistry Processes, School of Chemistry, Madurai Kamaraj University, Madurai - 625 021, India.
Kasi
K
Pitchumani