Alkaline earth metal catalyzed cascade, one-pot, solvent-free, and scalable synthesis of pyranocoumarins and benzo[b]pyrans

Abstract

Ca(OTf)2 catalyzed, cascade, one-pot, conjugate addition and annulation of various nucleophiles to the α,β-unsaturated carbonyl compounds for the synthesis of biologically potent pyranocoumarins and benzo[b]pyrans has been illustrated. This one-pot, solvent-free, green-synthesis employs simple reaction conditions, with high yields and endures the substrate diversity.