The first report on the green catalytic activity of water extract of Elaeagnus angustifolia L. leaves for the synthesis of diverse 4H-Pyrans

4H-pyran ring is a fascinating component in a broad variety of naturally occurring compounds, to the extent that the presence of 4H-pyran scaffold in organic compounds possessing a wide spectrum of biological properties such as anticancer, antimalarial, antimicrobial, antidyslipidemic as well as anti-inflammatory has been proven. It is remarkable to say that in order to treat some chronic diseases such as urinary incontinence, hypertension as well as ischemia, a number of drugs containing 4H-pyran moiety are prescribed. In the present study, a green and versatile approach for the synthesis of a variety of 2-amino-3-cyano-4H-pyrans is achieved via multicomponent reaction of an aldehyde, malononitrile and a CH-acid including 4-hydroxycoumarin, 3-methyl-1-phenyl-2-pyrazolin-5-one or ethyl acetoacetate/hydrazine hydrate. The reaction is properly progressed with taking advantage of extract of E. angustifolia L. leaves as a safe and natural catalyst. Moreover, the introduced approach is featured by mild reaction condition, short reaction time, simple work-up, easy to purification of products as well as avoiding the use of toxic solvents [1,2].