Supported Rhodium Nanoparticle-Catalyzed Intermolecular Regioselective Carbonylative Cyclization of Terminal Alkynes using Oxalic Acid as Sustainable C1 Source

Polystyrene-supported rhodium(0) (Rh@PS) nanoparticles (NPs) as a heterogeneous catalyst have been used for the synthesis of monocyclic 3,5-disubstituted cyclopent-2-enones from terminal alkynes and oxalic acid as the in situ C1 source following an intermolecular [2+2+1]–reductive carbonylative cyclization (RCC) reaction. Oxalic acid in the presence of Rh@PS catalyst plays a dual role by acting as CO source and reducing agent (H2) which makes the process feasible for the desired product synthesis. The ionic interaction of oxalic acid to the PS surface of Rh@PS helps to maintain the close vicinity and fruitful interaction with substrates and catalyst required for product formation.