Palladium‐Catalyzed Synthesis of Symmetrical and Unsymmetrical Ureas Using Chromium Hexacarbonyl as a Convenient and Safe Alternative Carbonyl Source

Abstract

Pd‐catalyzed synthesis of urea derivatives from aryl iodides and different aliphatic and aromatic amines using sodium azide and chromium hexacarbonyl is described. In this process, carbonylation of aryl iodides, Curtius rearrangement of aroyl azides, and nucleophilic addition of amines sequentially occur to afford the products in good to excellent yields. This protocol is operationally simple and displays a broad substrates scope.