Sevelamer as an efficient and reusable heterogeneous catalyst for the Knoevenagel reaction in water

A catalyst system of Sevelamer, a phosphate-binding drug, has been prepared and used in the Knoevenagel reaction of aromatic aldehydes in water to produce substituted electrophilic alkenes. The products were obtained in excellent yields. Several novel, related catalytic systems showed promising catalytic properties for aromatic and heterocyclic aldehydes. The Sevelamer catalyst can be recovered using simple filtration and reused numerous times(up to 15 times) in the aqueous Knoevenagel reaction without any significant lowering of activity.