Magnetically Recoverable CoFe ₂ O ₄ Nanoparticles: An Efficient Catalyst for One‐Pot, Four‐Component Synthesis of Functionalized Pyrroles

ABSTRACT Designing simple, cost‐effective, and efficient nano catalysts for synthesizing functionalized pyrroles is highly desirable, considering the enormous potential of the product in different fields. Herein, we report the synthesis of CoFe 2 O 4 nanoparticles (NPs) by the precipitation method followed by hydrothermal ageing at 160 °C for 4.0 h using different precipitating agents. The use of different precipitating agents has resulted in cubic crystalline CoFe 2 O 4 NPs of varying morphologies and sizes, as confirmed by the x‐ray diffraction and electron microscopy analysis. The room temperature magnetometry measurements revealed the formation of ferromagnetic CoFe 2 O 4 NPs. The as‐synthesized CoFe 2 O 4 NPs exhibited excellent catalytic activity in the synthesis of functionalized pyrrole via a multi‐component reaction between benzaldehyde, benzylamine, methyl acetoacetate, and nitromethane, resulting in an 85% yield of the intended product at 90 °C for 2.0 h. The developed protocol can efficiently produce a wide variety of functionalized pyrroles with 43%–87% yield. The efficiency of the catalyst has further been validated by successful gram‐scale syntheses. The protocol proves robust, maintaining its effectiveness as a magnetically recyclable catalyst for up to five cycles of reaction. Notably, this strategy stands out as mild and environmentally benign, producing a library of substrate scope with low catalyst loading.