Cp*Co^III–Catalyzed <i>syn</i>-Selective C–H Hydroarylation of Alkynes Using Benzamides: An Approach Toward Highly Conjugated Organic Frameworks

Hydroarylation of internal alkynes by cost-effective CoIII-catalysis, directed by N-tert-butyl amides, is achieved to avail mono- or dihydroarylated amide products selectively in an atom and step economic way. Several important functional groups were tolerated under the reaction conditions, and syn-hydroarylation products were exclusively isolated. Notably, a 4-fold C–H hydroarylation provided a highly conjugated organic framework in one step. Kinetic study with extensive deuterium labeling experiments were performed to support the proposed mechanism.