Direct Aerobic Carbonylation of C(sp2)-H and C(sp3)-H Bonds through Ni/Cu Synergistic Catalysis with DMF as the Carbonyl Source

The direct carbonylation of aromatic sp(2) and unactivated sp3 C-H bonds of amides was achieved via nickel/copper catalysis under atmospheric O-2 with the assistance of a bidentate directing group. The sp(2) C-H functionalization showed high regioselectivity and good functional group compatibility. The sp(3) C-H functionalization showed high site-selectivity by favoring the C-H bonds of alpha-methyl groups over those of the alpha-methylene, beta- or gamma-methyl groups. Moreover, this reaction showed a predominant preference for functionalizing the alpha-methyl over alpha-phenyl group. Mechanistic studies revealed that nickel/copper synergistic catalysis is involved in this process.