Nickel-Catalyzed Kumada Coupling of Boc-Activated Aromatic Amines via Nondirected Selective Aryl C-N Bond Cleavage.

A nickel-catalyzed Kumada coupling of aniline derivatives was developed by selective cleavage of aryl C-N bonds under mild reaction conditions. Without preinstallation of an ortho directing group on anilines, the cross-coupling reactions of Boc-protected aromatic amines with aryl Grignard reagents afforded unsymmetric biaryls. Mechanistic studies by DFT calculations revealed that the nickel-mediated C-N bond cleavage is the rate-limiting step.