Cobalt-Catalyzed C(sp2)-O Bond Formation by Directing Group Assisted C-H Activation

Metal-catalyzed C-sp2-H oxygenation is a synthetically invaluable transformation that enables the incorporation of synthetically useful functional groups, such as ethers and acetates, using a simple protocol. Compared to the well-developed palladium catalysis, the catalysis of cobalt, a 3d-transition metal, is recognized as a sustainable alternative for C-sp2-H oxygenation because of the natural abundance of cobalt and cost-effectiveness of the catalyst. In this Review, recent advances in cobalt-catalyzed C-sp2-H alkoxylation and acetoxylation are highlighted and several types of directing groups are discussed.

Automated summary

Metal-catalyzed C-sp2-H oxygenation is an important synthetic transformation that allows the incorporation of useful functional groups using a simple protocol. Cobalt catalysis, as a sustainable alternative, has gained attention due to its natural abundance and cost-effectiveness. In this Review, recent advances in cobalt-catalyzed C-sp2-H alkoxylation and acetoxylation are highlighted, along with discussions on various directing groups.