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

Abstract

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.