Sulfonamide Directivity Enables Ni-Catalyzed 1,2-Diarylation of Diverse Alkenyl Amines

1,2-Diarylation of alkenyl sulfonamides
with aryl iodides and aryl
boronic esters under nickel catalysis is reported. The developed method
tolerates coupling partners with disparate electronic properties and
substitution patterns. Di- and trisubstituted alkenes as well as alkenes
distal from the directing group are all accommodated. Control experiments
are consistent with a N–Ni coordination mode of the directing
group, which stands in contrast to a previous report on amide-directed
1,2-diarylation, which involves carbonyl coordination. The synthetic
utility of the method arises from the dual function of the sulfonamide
as both a directing group and a masked amine nucleophile. This is
highlighted by various product diversifications where complex amine
compounds are synthesized in a two-step sequence of N-functionalization and deprotection of the sulfonyl group.