Abstract
An unprecedented amine-catalyzed stereoselective reaction of α,α-dicyanomethylidenecarbazoles with indane-1,3-dione and aryl/heteroaryl aldehydes afforded a series of indanedione-fused benzo[a]carbazoles. The plausible mechanism for the formation of the final products result from the above MCR is described based on successive Knoevenagel/Michael/nucleophilic reactions. The products were obtained in moderate to good yields without the use of any chromatographic techniques. The structures of the synthesized spirocycloadducts were confirmed by elemental analysis and spectral data (FT-IR, 1H NMR, and 13C NMR).
GRAPHICAL ABSTRACT
Acknowledgments
We would like to thank the University of Mysore, for NMR data.