Phosphine-free double carbonylation of iodobenzene in the presence of reusable supported palladium catalysts

Various silica supported palladium catalysts were prepared and tested in the double carbonylation of iodobenzene in the presence of secondary amines. The catalysts were proved to produce alpha-ketoamide products with excellent selectivity in most cases. At the same time, bulky amines hindered double carbonylation and led to the formation of amides as the main products. Under optimal conditions, the catalysts could be recycled at least six times. An increase in the reaction time led to a decrease in the amount of leached palladium. (c) 2013 Elsevier B.V. All rights reserved.