Sm₂XMnO₆ (X = Co, Cr, and Fe) linked HPG on dendritic nanosilica as a recyclable green catalyst for eco-friendly synthesis of oxazolidinones from carbon dioxide

In this work, Sm₂XMnO₆ (X = Co, Cr, Fe) nanocatalysts with high surface area and readily accessible active sites were successfully synthesized using a simple strategy based on dendritic fibrous nanosilica (DFNS). The DFNS surface was functionalized with hyperbranched polyglycerol (HPG) groups containing multiple carboxyl moieties, which served as robust anchoring sites. This modification enabled the uniform dispersion of Sm₂XMnO₆ nanoparticles across the DFNS fibers without aggregation, while the amplification effect of HPG facilitated high loading capacities. Acting as stable and reusable heterogeneous catalysts, the DFNS/HPG/Sm₂XMnO₆ composites effectively promoted the transformation of anilines, CO₂, and olefins into 3-aryl-2-oxazolidinones. The fibrous DFNS structure not only enhanced adsorption capacity but also allowed straightforward recovery of the catalyst without significant loss of yield, owing to its strong chemical durability. With excellent mechanical strength, ionic conductivity, thermal stability, and colloidal persistence, the system represents an ideal nanocatalyst within a host guest framework. A broad range of olefins, regardless of electronic properties, were converted into desired products, while the heterogeneous catalytic environment posed no barriers to reaction progress. The 3-aryl-2-oxazolidinones could be readily isolated from the reaction mixture, and the DFNS/HPG/Sm₂XMnO₆ catalyst was efficiently recycled through several runs without significant loss of activity or selectivity. • DFNS/HPG/Sm₂XMnO₆ (X = Co, Cr, Fe) nanocatalysts were successfully synthesized via a simple and green route. • The hyperbranched polyglycerol (HPG) layer enhanced nanoparticle dispersion and prevented metal leaching. • The catalysts showed excellent activity and recyclability for CO₂ conversion to 3-aryl-2-oxazolidinones. • The synergistic effect of DFNS architecture and HPG modification ensured high efficiency under mild conditions.