Nickel-Catalyzed Enantioselective Reductive Arylation of Common Ketones.

A nickel complex of chiral bisoxazolines catalyzed the stereoselective reductive arylation of ketones in high enantioselectivity. A range of common acyclic and cyclic ketones reacted without the aid of directing groups. Mechanistic studies using isolated complex of a chiral bis(oxazoline) (L)Ni(Ar)Br revealed that Mn reduction was not needed, while Lewis acidic titanium alkoxides were critical to ketone insertion.