Nickel-Catalyzed C–N Cross-Coupling of Ammonia, (Hetero)anilines, and Indoles with Activated (Hetero)aryl Chlorides Enabled by Ligand Design

The
Ni­(II) precatalyst (C1) featuring the phosphonite
ancillary ligand Phen-DalPhos (L1) was employed in the
cross-coupling of (hetero)­anilines with (hetero)­aryl chlorides and
in the diarylation of ammonia with (hetero)­aryl chlorides to afford
heteroatom-dense di­(hetero)­arylamines. The PAd2-DalPhos precatalyst C4 provided complementary reactivity in cross-couplings of
indoles with (hetero)­aryl chlorides. Taken together, the demonstration
of room-temperature reactivity within each of the reaction classes
examined and the observation of useful chemoselectivity at low loading
(≤0.5 mol % Ni) and on gram-scale distinguishes C1 and C4 from other metal catalysts (i.e., copper, palladium,
nickel, or other) within the field of C–N cross-coupling chemistry.