A rapid-room temperature synthesis of α-cyanoacrylates, α-cyanoacrylonitriles and 4H-pyrans using water extract of pomegranate ash as catalytic media

Abstract

In this article we report a sustainable and rapid-room temperature synthesis of α-cyanoacrylonitriles, α-cyanoacrylates, and 4H-pyransvia the condensation of active methylene compounds with aldehydes, and a three-component reaction of 1,3-dicarbonyl compounds/4-hydroxycoumarins, active methylene compounds and acetylene dicarboxylates in water extract of pomegranate ash (WEPA). The agro-waste-derived WEPA acts both as catalyst and aqueous reaction medium. The products of this process were separated by simple filtration and purified by recrystallization. This protocol did not require organic solvent-based work-up and column chromatography-assisted purifications. The use of renewable catalytic media, good reusability of catalyst, ease of handling, ambient and depleting resources-based catalyst free conditions, avoid of volatile organic solvents throughout the process, excellent product yields, and actual usage of waste are the highlights of this process.