A Green, Novel and Efficient Protocol for the Preparation of Diverse 4H-Pyrans: The First Report on the Catalytic Activity of Water Extract of Elaeagnus angustifolia Leaves in Organic Reactions

Abstract

In the present study, a green and versatile approach for the synthesis of a variety of 2-amino-3-cyano-4H-pyrans is reported via multicomponent reaction of aldehydes, malononitrile, and CH-acids including, 4-hydroxycoumarin, 3-methyl-1-phenyl-2-pyrazoline-5-one or ethyl acetoacetate/hydrazine hydrate. The reaction is properly progressed with taking advantage of extract of E. angustifolia leaves as a safe and natural catalyst. Moreover, the introduced approach is featured by mild reaction condition, short reaction time, simple work-up, and easy purification of products as well as avoiding the use of toxic solvents.

Graphical Abstract

Keywords:

• 4H-pyaran
• CH-acids
• Elaeagnus angustifolia leaves
• green catalyst
• malononitrile

Acknowledgments

We gratefully appreciate the financial support from the Research Council of University of Sistan and Baluchestan.