Pd-catalyzed asymmetric hydrogenation of alpha-fluorinated iminoesters in fluorinated alcohol: a new and catalytic enantioselective synthesis of fluoro alpha-amino acid derivatives.

[figure: see text] Under hydrogen pressure, a catalytic amount of palladium(II) trifluoroacetate and 2,2'-bis(diphenylphosphino)-1,1'-binaphthyl (BINAP) promoted asymmetric hydrogenation of alpha-fluorinated iminoesters to afford highly enantioenriched beta-fluorinated alpha-amino esters. The yield and ee were much improved by employing fluorinated alcohols such as 2,2,2-trifluoroethanol (up to 91% ee).