AlPo4 as a new,highly efficient and reusable heterogeneous catalyst for the selective synthesis of β-enamino ketones and esters under solvent-free conditions

The potassium hydrogenophosphate (alpo4) has been found to be highly efficient heterogeneous catalyst for the synthesis of β-enamino ketones and esters by the enamination ofvarious primary amines with β-dicarbonyl compounds under solvent-free conditions. the important features of this methodology are broad substrate scope,high yield,no requirementof metal catalysts,high regio- and chemoselectivity and environmental friendliness. in addition,the catalyst could be recovered easily after the reactions and reused without evident loss of reactivity.