Base-free transfer hydrogenation of aldehydes and ketones catalyzed by imidazolin-2-iminato actinide complexes

A series of thorium(iv) (3, 4, 9, 10) and uranium(iv) (5, 6, 11, 12) complexes decorated with the unsymmetrical imidazolin-2-iminato ligands L₁ and L₂ were synthesized and found to be effective as catalysts in the transfer hydrogenation of aldehydes and ketones with 2-propanol to form the corresponding alcohols with good yields, representing a rare example for actinides as transfer hydrogenation catalysts with alcohols. The transfer hydrogenation of aldehydes and ketones was found to be selective, tolerating a wide range of other functional groups, including those prone to reduction, such as nitro, alkynes, and nitriles. The neutral imine ligand was found to be coordinated in the active catalyst along with the alkoxo group.