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 C-1 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 (H-2) 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.