NiSO4·6H2O as a new, efficient, and reusable catalyst for the α-aminophosphonates synthesis under mild and eco-friendly conditions

Abstract

Nickel (II) sulfate hexahydrate is used for the first time as an efficient catalyst for the one-pot synthesis of α-aminophosphonates by three-component condensation reaction of aromatic aldehyde, primary amine, and diethylphosphite under mild and eco-friendly conditions. NiSO4·6H2O was used with a catalytic amount of 5 mol% at room temperature, without solvent in the reaction. A series of the desired α-aminophosphonates are obtained after a simple work-up procedure, with excellent yields (up to 92 %) within a short reaction time of 10–20 min in all cases. This heterogeneous catalyst was reused several times with the same activity. The present approach offers the advantages of a clean reaction, simple methodology, easy purification, and economic availability of the catalyst.