Evolution of titanium(IV) alkoxides and Raney nickel for asymmetric reductive amination of prochiral aliphatic ketones

[GRAPHICS] A new method for the one-pot asymmetric reductive amination of prochiral aliphatic ketones has been developed. The previously unexplored reagent combination of Ti((OPr)-Pr-/)(4)/Raney Ni/H-2 in the presence of (R)- or (S)-alpha-methylbenzylamine provides good to excellent yield (76-90%) and diastereomeric excess (72-98%). The second step, hydrogenolysis, provides the corresponding primary amine in high yield (88-93%) and with uncompromised enantiomeric excess.