Asymmetric Fluorination of α‐Aryl Acetic Acid Derivatives with the Catalytic System NiCl2–Binap/R3SiOTf/2,6‐Lutidine

Not binary, but trinary: A binary system consisting of Ni(OTf)2–binap complex and 2,6-lutidine failed to promote the asymmetric fluorination of ester equivalents. However, upon the addition of a substoichiometric amount of Et3SiOTf to the NiCl2–binap/2,6-lutidine catalyst, the monofluorinated products were obtained in good yield with high enantioselectivity (see example). NFSI=N-fluorobenzenesulfonimide, Tf=trifluoromethanesulfonyl.