A facile reductive carbonylation reaction of nitroarenes to N-arylformamide synthesis was investigated under polymer supported palladium (Pd@PS) nanoparticles catalyzed conditions. Dual role of oxalic acid dihydrate ((CO 2 H) 2 · 2H 2 O) as H 2 source for hydrogenation and CO source for carbonylation reaction for desired products synthesis was critically investigated under favorable DMF solvent conditions. Several cross experiments were performed to establish the best possible hypothesis for the proposed mechanism and understanding about the involvement of CO in the reaction pathway. Further, ortho-substituted nitroarenes were found to be highly specific for facile para-hydroxylation to give corresponding parahydroxy N-aryl formamides.

A very unusual role of polystyrene stabilized rhodium (Rh@PS) nanoparticles as a supported catalyst is described for “reverse-esterification” of ethanol with benzyl/alkyl alcohols or aldehydes.

Polystyrene-supported palladium(0) (Pd@PS) nanoparticles as a heterogeneous catalyst have been developed for caboxylation of aryl halides, alkenylsilanes, and organoboronic acids to produce the corresponding carboxylic acids with minor quantities of corresponding aldehydes using bench-stable and inexpensive oxalic acid as the C1 source under focused microwave irradiation. The close vicinity of oxalic acid to Pd@PS maintained through ionic bonding helped to produce CO2 over the catalytic surface that concurrently participated in the carboxylation reaction.