Room-temperature C-H bond alkynylation by merging cobalt and photocatalysts

A new protocol is developed for the mono- and bis-ortho-C-H alkynylation of easily accessible benzamide derivatives using alkynyl bromides at room temperature by merging cobalt and photocatalysts. The diverse reactivity of various alkynyl bromides towards the C-H alkynylation and competing C-H/N-H bond annulation reactions has been demonstrated to give the corresponding products in good yields with excellent functional group tolerance.

Automated summary

A new protocol has been developed for mono- and bis-ortho-C-H alkynylation of easily accessible benzamide derivatives using alkynyl bromides at room temperature by combining cobalt and photocatalysts. Different alkynyl bromides have shown diverse reactivity towards C-H alkynylation and competing C-H/N-H bond annulation reactions, resulting in good yields with excellent functional group tolerance.