Nickel−NHC-Catalyzed α-Arylation of Acyclic Ketones and Amination of Haloarenes and Unexpected Preferential <i>N</i>-Arylation of 4-Aminopropiophenone

Abstract

Arylation of both acyclic ketones and primary and secondary amines was achieved using a new, simple, stable, and easy-to-access nickel(II)-halide complex bearing mixed PPh3/N-heterocyclic carbene ligands as a catalyst precursor. Acyclic ketones were first arylated at the alpha-position with the nickel catalyst. On the other hand, less basic amines, such as diphenylamine and 4-aminobenzophenone, were more favorable in the catalytic amination of haloarenes than basic amines, contrary to previous reports. N-Arylation of 4-aminopropiophenone was found to proceed selectively without causing alpha-arylation of the ketone group.