SO42−/CexZr1−xO2-catalyzed Synthesis of N-tert-Butylamides from Various Nitriles under Solvent-free Conditions

The synthesis of N-tert-butylamides using SO42−/CexZr1−xO2 catalysts under solvent-free conditions is reported. The methodology has several advantages such as reusability of the catalyst, solvent-free conditions, easy workup, and comparable yield of N-tert-butylamides. A variety of aliphatic, aromatic, and acid-sensitive substrates give high to moderate yields of the corresponding N-tert-butylamides. Surface acidities of the catalysts were correlated with the results obtained. To the best of our knowledge, this is the first report of a modified Ritter reaction on SO42−/CexZr1−xO2 using tert-butyl acetate as carbocationic source.