Supported Palladium Nanoparticles-Catalyzed Synthesis of 3-Substituted 2-Quinolones from 2-Iodoanilines and Alkynes Using Oxalic Acid as C1 Source

3-Aryl/alkyl-2-quinolones were synthesized employing microwave assisted multicomponent reaction of 2-iodoanilines, terminal alkynes and oxalic acid dihydrate ((CO2H)(2) 2H(2)O) under polystyrene supported palladium (Pd@PS) nanoparticles-catalyzed conditions. The use of a heterogeneous palladium catalyst was explored first time for 2-quinolone synthesis involving carbonylation reaction employing (CO2H)(2) 2H(2)O as a solid and bench stable carbon monoxide (CO) source. The reaction exhibited good substrate generality for 2-iodoanilines and alkynes with wide functional group tolerance and good regio-selectivity. The ligand free operation, recyclability of heterogeneous Pd@PS catalyst and use of bench stable C1 source are the invaluable merits of the protocol.