Cu O Nanocrystals-Catalyzed Photoredox Sonogashira Coupling of Terminal Alkynes and Arylhalides Enhanced by CO.

Herein the first visible-light-activated Sonogashira C-C coupling reaction at room temperature catalyzed by single-metal heterogeneous Cu O truncated nanocubes (Cu O TNCs) was developed. A wide variety of aryl halides and terminal alkynes worked well in this recyclable heterogeneous photochemical process to form the corresponding Sonogashira C-C coupling products in good yields. Mechanistic control studies indicated that CO enhances the formation of light-absorbing heterogeneous surface-bound Cu -phenylacetylide (λ =472 nm), which further undergoes single-electron transfer with aryl iodides/bromides to enable Sonogashira C -C bond formation. In contrast to literature-reported bimetallic TiO -containing nanoparticles as photocatalyst, this work avoided the need of cocatalysis by TiO . Single-metal Cu in Cu O TNCs was solely responsible for the observed C -C coupling reactions under CO atmosphere.