Cobalt-catalyzed C8-H sulfonylation of 1-naphthylamine derivatives with sodium sulfinates

A facile and efficient protocol for cobalt-catalyzed regioselective C8-H sulfonylation of 1-naphthylamine derivatives with sodium sulfinates, affording sulfonylated naphthylamines in moderate to good yields, is described. The reaction exhibits broad functional group tolerance and high regioselectivity. Note that the addition of a catalytic amount of NFSI or Selectfluor as the auxiliary ligand would enhance the reaction efficiency. Furthermore, the picolinamide moiety as a bidentate directing group likely plays a key role in this regioselective transformation.