Applications of ferromagnetic in situ generated α-Fe₂O₃ NPs as an efficient and recyclable catalyst for carbon–carbon bond formation via Sonogashira–Hagihara coupling reactions and the synthesis of pyran derivatives by hetero-Diels–Alder reactions have been demonstrated. This catalytic system is easily recoverable due to the ferromagnetic nature of α-Fe₂O₃ NPs and can be reused with sustained selectivity and activity.