Direct Asymmetric Hydrogenation of N-Methyl and N-Alkyl Imines with an Ir(III)H Catalyst

A novel cationic [IrH(THF)(P,N)-(imine)] [BArF] catalyst containing a P-stereogenic MaxPHOX ligand is described for the direct asymmetric hydrogenation of N-methyl and N-alkyl imines. This is the first catalytic system to attain high enantioselectivity (up to 94% ee) in this type of transformation. The labile tetrahydrofuran ligand allows for effective activation and reactivity, even at low temperatures. Density functional theory calculations allowed the rationalization of the stereochemical course of the reaction.