Nickel Nanoparticles as Semiheterogeneous Catalyst for One-Pot, Three-Component Synthesis of 2-Amino-4H-pyrans and Pyran Annulated Heterocyclic Moieties

Abstract

An efficient route for the synthesis of 2-amino-4H-pyrans and pyran annulated heterocyclic moieties has been reported via one-pot tandem Knoevenagel–cyclocondensation of aldehydes, malononitrile, and carbocyclic/heterocyclic 1,3-diones in the presence of stabilized nickel nanoparticles in ethylene glycol at room temperature. A wide range of aromatic aldehydes undergo the condensation readily to afford the pharmacologically important compounds in excellent yields. Bis-pyranization has been observed in the reactions of terephthaldehyde.

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GRAPHICAL ABSTRACT

Keywords:

• Aromatic aldehydes
• 1,3-dicarbonyls
• 4H-pyrans
• malononitrile
• nickel nanoparticles

ACKNOWLEDGMENT

K.V. is thankful to the Council of Scientific and Industrial Research, New Delhi, India, for the award of junior and senior research fellowships.