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 sp² and unactivated sp³ C-H bonds of amides was achieved via nickel/copper catalysis under atmospheric O₂ with the assistance of a bidentate directing group. The sp² C-H functionalization showed high regioselectivity and good functional group compatibility. The sp³ C-H functionalization showed high site-selectivity by favoring the C-H bonds of α-methyl groups over those of the α-methylene, β- or γ-methyl groups. Moreover, this reaction showed a predominant preference for functionalizing the α-methyl over α-phenyl group. Mechanistic studies revealed that nickel/copper synergistic catalysis is involved in this process.