In the present study, open metal site iron-based MOF [MIL-100(Fe)], by a solvothermal method with polygonal morphology, are synthesised and then applied as a heterogeneous green catalyst for aza-Michael addition of various amines with alpha, beta-unsaturated compounds. The MIL-100(Fe) was found to be efficient, selective, green and heterogeneous catalyst for the aza-Michael reaction. The proposed catalyst has better recyclability and can be reused six times without apparent loss of activity. [GRAPHICS] .