A magnetically retrievable, efficient, and benign maghemite-Cu nanocatalyst was synthesized from inexpensive precursors and applied for C-O, C-N, and C-S bond-formation reactions. The obtained maghemite-Cu nanocatalyst was characterized by various techniques such as XRD, X-ray photoelectron spectroscopy, field-emission gun SEM with energy-dispersive spectroscopy, atomic absorption spectroscopy, TEM, high-angle annular dark-field scanning transmission electron microscopy, FTIR spectroscopy, and Mossbauer spectroscopy. Excellent catalytic activity, ease of recovery, and reusability without a significant loss of yield make the present protocol highly sustainable to deal with industrial and environmental concerns.