Recycling of organocatalysts is an important aspect in green chemistry. Several techniques have been applied to address this issue ranging from traditional separation techniques (extraction, chromatography) to immobilization on solid supports. Magnetic separation, i.e. attraction of the catalyst by an external magnet and decantation of the supernatant appeared as a new way for separation of organocatalysts omitting problems connected to filtration when solid supported catalysts are used. In this publication, the state of the art of magnetic nanoparticle-supported organocatalysts is reviewed demonstrating a wide range of applications but at the same time hitherto unaddressed fields awaiting future exploration are discussed.

Highly oriented, layered, and mechanically resilient films of polydopamine (PDA) have been synthesized from the air/water interface. The films show a unique layered structure, as shown by scanning and transmission electron studies (SEM/TEM) and X-ray diffraction analysis (XRD), which resemble that of 2D layered materials. The films exhibit a composition typical of PDA-based materials, as evidenced by X-ray photoelectron spectroscopy (XPS); moreover, the samples present the distinctive resonance modes of PDA-based nanomaterials in Raman and infrared spectroscopy (FTIR) experiments. The presence of highly ordinated 3–4 protomolecule stacking, taking place at the air/water interface, with a unique eumelanin-like supramolecular arrangement is presented. Moreover, the films show superior mechanical resilience with E = 13 ± 4 GPa and H = 0.21 ± 0.03 GPa, as revealed by nanoindentation experiments, making them highly resilient and easily transferable. Finally, the ordering induced by the interface opens many possibilities for further studies, including those regarding the supramolecular structure on PDA due to their similarity to 2D layered materials.