An iron-based metal–organic framework, Fe₃O(BPDC)₃, was synthesized, and was characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR) spectroscopy, atomic absorption spectrophotometry (AAS), and nitrogen physisorption measurements. The Fe-MOF could be used as an efficient heterogeneous catalyst for the synthesis of coumarins from salicylaldehydes and activated methylene compounds in the presence of tert-butyl hydroperoxide as the oxidant under base-free conditions. The Fe₃O(BPDC)₃ was more catalytically active for the synthesis of coumarins than other MOFs such as Cu₂(BDC)₂(BPY), Cu₃(BTC)₂, Cu₂(BDC)₂(DABCO), Ni₂(BDC)₂(DABCO), and Fe₃O(BDC)₃. This Fe-MOF also offered significantly higher catalytic activity for the transformation than that of common metal salts such as FeCl₃, Fe(NO₃)₃, FeSO₄, CuCl₂, CuCl, Cu(NO₃)₂, and Ni(NO₃)₂. The Fe₃O(BPDC)₃ catalyst could be recovered and reused several times without significant degradation in catalytic activity. To the best of our knowledge, the oxidant-promoted formation of coumarins under heterogeneous catalysis conditions was not previously mentioned in the literature.