Iridium-Catalyzed Reductive Amination of Levulinic Acid to Pyrrolidinones under H2 in Water

The synthesis of pyrrolidinones from reductive amination of levulinic acid (LA) with primary amines is reported. Pyrrolidinones have various applications such as surfactants, pharmaceutical intermediates, dispersants, and solvents. The half-sandwich Cp* Ir complex (Cp* is 1,2,3,4,5-pentamethylcyclopenta-1,3-diene) coordinated by bipyridine ligand bearing both dimethylamino and ortho-hydroxyl groups showed high catalytic activity for the reductive amination of LA. A range of primary amines, such as aromatic and benzyl amines, were readily converted to corresponding pyrrolidinones in good yields.