The water-dispersible and magnetic separable Au/Fe3O4/s-G nanocomposite was used as an effective and reusable heterogeneous catalyst for the Ullmann homocoupling.

Phosphotungstic acid (H3PW12O40) was used as an efficient and recyclable catalyst for the synthesis of polysubstituted quinolines through the Friedländer condensation of 2-aminoarylketone with carbonyl compounds, which was achieved by conventional heating under solvent-free conditions.

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Gold nanoparticles were decorated onto sulfonated three‐dimensional graphene (3DG‐SO3H) through spontaneous chemical reduction of HAuCl4 by 3DG‐SO3H. This nanocomposite exhibited excellent catalytic activity for the synthesis of symmetric biaryls via the Ullmann homocoupling of aryl iodides in an aqueous medium. Additionally, this nanocomposite was used as a catalyst for the reduction of p‐nitrophenol to p‐aminophenol. The catalyst could be used more than six times successively without significant deactivation.