Butane‐1‐sulfonic acid immobilized on magnetic Fe3O4@SiO2 nanoparticles (Fe3O4@SiO2‐Sultone) was easily prepared via direct ring opening of 1,4‐butanesultone with nanomagnetic Fe3O4@SiO2. The prepared reagent was characterized and used for the efficient promotion of the synthesis of barbituric acid and pyrano[2,3‐d] pyrimidine derivatives. All reactions were performed under mild and completely heterogeneous reaction conditions affording products in good to high yields. The catalyst is easily isolated from the reaction mixture by magnetic decantation and can be reused at least eight times without significant loss in activity.

A mild, simple and efficient procedure for the preparation of barbituric acid and pyrano[2,3-d]pyrimidine derivatives in aqueous media is described using 4-(4-propylpiperazine-1-yl)butane-1-sulfonic acid-modified silica-coated magnetic nanoparticles as a novel and reusable catalyst. The catalyst was easily isolated from the reaction mixture by magnetic decantation using an external magnet and reused at least eight times without significant degradation in activity.

Herein, we describe the straightforward synthesis and thorough characterization of a magnetically‐separable heterogeneous catalyst comprised of 1–3 nm‐sized Pd nanoparticles immobilized on a mesoporous silica‐magnetite composite (Pd0‐AmP‐SMC). Catalytic evaluations were conducted using Suzuki‐Miyaura cross‐couplings as the model reactions, for which this Pd nanocatalyst exhibited high performance in an environmentally‐friendly solvent mixture. Additionally, this Pd nanocatalyst could be re‐used up to five cycles without any observable loss of activity, and separation of the catalyst could be conveniently done by a magnet.

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