silica-based nanospheres supported palladium nanoparticles as a recyclable catalyst for synthesis of primary amide

Amide bond formation is one of the most important organic chemistry reactions is essential for the synthesis of drugs, natural products and polymers such as peptides, bortezomib, for example (an anticancer drug) and nylon 66. [1]. in fact, more than 25% of drugs contain at least one amide group [2]. in the past few years, in search of more economical and cost-effective atom protocolsfor synthesis amide, metal transformations have emerged as attractive alternatives, offering the possibility to develop previously inaccessible paths starting from substrates other than carboxylic acids and their derivatives [3]. on the other hand, heterogeneous catalysts play an important role in the field of organic transformations. in this work we synthesized a new hollow inorganic polymer nanospheres (pani-silicahns) for stabilizing of pd nanoparticles as a green and stable catalyst for synthesis of primary amide (scheme 1). the catalytic system was investigated for a wide range of aldehyde in the presence of 5 mol% of catalyst at 80o c. pdnps/hsn demonstrated excellent performance with high yields (up to 95%) for the synthesis of corresponding amides. this catalyst was recovered and reused for 7 consecutive times without loss of activity.