Iron-Catalyzed ortho C-H Arylation and Methylation of Pivalophenone N-H Imines.

Iron-catalyzed ortho C-H arylation and methylation reactions of pivalophenone N-H imines are reported. The pivaloyl N-H imine proved an excellent directing group for the arylation with diarylzinc reagents in the presence of an iron-diphosphine catalyst and 2,3-dichlorobutane at room temperature. A similar catalytic system also allowed methylation with Me3 Al at 70 °C. The pivaloyl imine of the product could be readily converted to a cyano group, thus allowing convenient preparation of ortho-functionalized benzonitriles.