Silica supported palladium-phosphine as a reusable catalyst for alkoxycarbonylation and aminocarbonylation of aryl and heteroaryl iodides

Silica-supported palladium phosphine complexes were prepared for alkoxycarbonylation and aminocarbonylation of aryl iodides. These catalysts were highly efficient for the carbonylation of unprotected hydroxy-aryl, amino-aryl, iodoindole and iodopyrazole. The carbonylation of unprotected iodopyrazole is challenging and their carbonylation was achieved for the first and obtained corresponding carbonylative products are biologically active. The applicability of developed protocols tolerates wide range of functional groups with excellent yields. The catalyst was easily recovered and shows significant recyclability up to five consecutive cycles without loss in its catalytic activity and selectivity. The prepared catalysts were characterized by different techniques such as FEG-SEM, EDS, FTIR, XPS and ICP-AES spectroscopy.