Selective Formation of Benzoyl Ureas by Selenium-Catalyzed Oxidative-Reductive Carbonylation of Benzoyl Amide and Aromatic Nitro Compounds

摘要

Benzoyl ureas have a wide variety of uses. In particular, certain benzoyl-substituted ureas are effective insecticides. Traditionally, such compounds have been made by reacting an amine with a carbonyl isocyanate or an amide with an isocyanate. These routes proceed with high yields, but involve a relatively large number of steps from commercially-available starting materials, and have the disadvantage of requiring an isocyanate. The most widely used methods at present involve phosgenation of the appropriate amide or amine. Although this process is also efficient and gives high yields, but phosgene is exceedingly toxic, so very special handling precautions are necessary. In recent years, attention has been paid to a very promising non-phosgene process for the synthesis of various benzoyl-substituted ureas, which includes the reacting of an aromatic nitro-compound with a primary or secondary amide and carbon monoxide, in the presence of a catalyst comprising a Group Ⅷ metal from iridium, rhodium, ruthenium, palladium, platinum or vanadium salt and a ligand which is an organo-phosphorus, organo-arsenic, organo-antimony or organo-nitrogen compound having a lone pair of electrons.