Triethanolamine-Catalyzed One-Pot Three-Component Domino Annulation Leading to 4H-Pyrano[3,2-c]coumarins: Catalyst Reusability and Decagram-Scale Synthesis
A triethanolamine (TEOA)-catalyzed, one-pot, three-component reaction of 4-hydroxycoumarin, aldehydes, and malononitrile was developed as a highly atom-economic domino protocol for the synthesis of biologically significant 4H-pyrano[3,2-c]coumarins. This cascade sequence proceeds through the successive formation of thr...