Oxidative decarboxylative arylation reactions are potentially attractive routes to generate biaryl structures from simple and readily available precursors; yet, they are underutilized, because of limitations in the carboxylic acid scope. Here, we report a nickel catalyst system that enables the selective decarboxylative arylation of unactivated C–H bonds with a broad scope of (hetero)­aromatic carboxylate coupling partners. Preliminary mechanistic insights suggest that the efficiency and selectivity of this protocol originate from cooperation between Ni and Ag.

A nickel-catalyzed oxidative decarboxylative annulation reaction of simple benzamides and (hetero)aromatic carboxylates has been developed. This reaction provides access to a large array of phenanthridinones and their heterocyclic analogues, highlighting the utility and versatility of oxidative decarboxylative coupling strategies for C-C bond formation.

Ni-catalyzed C−H functionalization reactions are becoming efficient routes to access a variety of functionalized arenes, yet the mechanisms of these catalytic C−C coupling reactions are not well understood. Here, we report the catalytic and stoichiometric arylation reactions of a nickel(II) metallacycle. Treatment of this species with silver(I)−aryl complexes results in facile arylation, consistent with a redox transmetalation step. Additionally, treatment with electrophilic coupling partners generates C−C and C−S bonds. We anticipate that this redox transmetalation step may be relevant to other coupling reactions that employ silver salts as additives.

Ni-catalyzed C-H functionalization reactions are becoming efficient routes to access a variety of functionalized arenes, yet the mechanisms of these catalytic C-C coupling reactions are not well understood. Here we report the catalytic and stoichiometric arylation reactions of a nickel(II) metallacycle. Treatment of this species with silver(I)-aryl complexes results in facile arylation, consistent with a redox transmetalation step. Additionally, treatment with electrophilic coupling partners generates new C-C and C-S bonds. We anticipate that this redox transmetalation step may be relevant to other coupling reactions that employ silver salts as additives.

Ni-catalyzed C-H functionalization reactions are becoming efficient routes to access a variety of functionalized arenes, yet the mechanisms of these catalytic C-C coupling reactions are not well understood. Here we report the catalytic and stoichiometric arylation reactions of a nickel(II) metallacycle. Treatment of this species with silver(I)-aryl complexes results in facile arylation, consistent with a redox transmetalation step. Additionally, treatment with electrophilic coupling partners generates new C-C and C-S bonds. We anticipate that this redox transmetalation step may be relevant to other coupling reactions that employ silver salts as additives.