A Sustainable Protocol for C=C Bonds Synthesis Using Water Extract of Annona Squamosa Fruit Shell Ash (WEASF)

The use of bioresource-derived wastes to valuable organic reactions is a new and fascinating trend in the current-day chemistry which aims at the decrease/elimination of the use of depleting resources based chemicals. This article discusses a sustainable protocol for the synthesis of C=C bonds via the Knoevenagel condensation reaction of & alpha;-cyano esters with aldehydes using water extract of Annona squamosa fruit shell ash (WEASF) as catalyst. These reactions have been conducted at room temperature (RT) in aqueous media and the products are purified by recrystallization. WEASF acts as biorenewable base and the process avoids the organic solvents and column-based purifications of products. The bio-derived WEASF also showed its high reusability in the current protocol and is a sustainable alternative to existing methods of making polysubstituted olefins.