Copper‐Catalyzed Base‐free Protocol for the Sonogashira‐type Coupling of Phenylacetylenes with Boronic Acid Derivatives under Air

Abstract A base‐free Cu‐catalyzed protocol for the synthesis of internal alkynes using phenylacetylenes and boronic acid derivatives has been developed. We have used the less expensive catalyst CuI in greener solvent methanol using air as oxidant for the synthesis of diarylacetylenes. The methodology furnished the diarylacetylene derivatives in moderate to excellent yields.