Water extract of pomegranate ash as waste-originated biorenewable catalyst for the novel synthesis of chiral tert‑butanesulfinyl aldimines in water

Abstract

• Biorenewable waste-derived base as catalyst in water. • Highly sustainable synthesis of chiral tert ‑butanesulfinyl aldimines. • Non-chromatographic purification of products. • Fair reusability of the renewable catalyst and multi-gram scale viability. The renewable materials catalyzed reactions in aqueous media is urgently needed and highly fascinating task in the current state of organic synthesis. Here, we report a novel and sustainable protocol for the biorenewable, waste-originated water extract of pomegranate ash (WEPA) catalyzed condensation reaction of tert ‑butanesulfinamides and aldehydes in water to produce chiral tert ‑butanesulfinyl aldimines ( t BSAIs) in high yields. The products are separated by filtration and purified by recrystallization; avoids the extraction and column chromatographic separation steps. The reaction was performed with high yields in several consecutive recycles of the catalyst and medium, and further this method is highly effective for the multi-gram scale synthesis of t BSAIs. The application of biorenewable catalyst, added metal/catalyst free conditions, absence of volatile organic solvents and additives, vast substrate feasibility, economical profiles, easy operation, reusability of the catalyst, large scale viability, non-chromatographic purification of products and tremendous future perspective are the sparkling insights of this development. A novel and versatile protocol has been developed for the synthesis of tert‑butanesulfinyl aldimines using water extract of pomegranate ash (WEPA) as catalyst in water.