Indium-doped ZnO nanoparticles as efficient heterogeneous catalysts for the green synthesis of β-amino ketones.

The development of sustainable and efficient catalytic systems remains a critical challenge in organic synthesis, particularly for the preparation of β-amino ketones, which are valuable intermediates in pharmaceuticals and fine chemicals. Conventional synthesis methods often rely on toxic reagents, harsh conditions, or non-recyclable catalysts, limiting their green and practical applicability. To address these challenges, we report a one-pot green synthesis of β-amino ketones using indium-doped ZnO nanomaterials as an efficient heterogeneous catalyst under mild, room-temperature conditions in ethanol. The catalyst was prepared via a simple and time-efficient sol-gel auto-combustion technique, where DMF acted simultaneously as the solvent and fuel, eliminating the need for distilled water. Comprehensive characterisation, including XRD, UV-vis, FTIR, and TEM analyses, confirmed the successful incorporation of indium into the ZnO lattice, accompanied by a red shift in the band gap and a structural transition from hexagonal wurtzite to spherical morphologies. These nanostructure modifications significantly enhanced catalytic activity, enabling the effective activation of carbonyl groups and promoting the synthesis of β-amino ketones in high yields. Beyond efficiency, the process is environmentally benign, cost-effective, and the catalyst is readily recyclable, making it a promising alternative to conventional homogeneous and metal-catalysed methods. This work highlights the potential of indium-doped ZnO nanostructures as green catalysts for scalable and sustainable organic transformations.