A Family of Active Iridium Catalysts for Transfer Hydrogenation of Ketones

The air-stable iridium chlorodihydride complex IrH2Cl[(iPr2PC2H4)2NH], 1, was prepared from the reaction of [IrCl(coe)2]2 with the pincer ligand (iPr2PC2H4)2NH in 2-propanol at 80 °C. Reaction of 1 with KOtBu in THF resulted in the formation of the air-sensitive amidodihydride complex IrH2[(iPr2PC2H4)2N], 2, which in the presence of 2-propanol readily forms the moderately air-stable trihydride complex IrH3[(iPr2PC2H4)2NH], 3. The trihydride and amidodihydride complexes in the absence of a base are exceptionally active catalysts for the transfer hydrogenation of ketones in 2-propanol.