Organocatalyzed domino reactions: diversity oriented synthesis of pyran-annulated scaffolds using in situ-developed benzylidenemalononitriles

Molecular diversity for the synthesis of pyran annulated heterocyclic scaffolds has been achieved from the multicomponent reaction of aldehyde, malonitrile and a third participant such as dimedone, barbituric acid and 3-methyl-1H-pyrazol-5(4H)-one. The reactions completed successfully using in situ-developed benzylidenemalononitriles via Knoevenagel reaction catalyzed by aspartic acid as a new efficient organo-catalyst in aqueous ethanol as a green medium at ambient conditions.