Cu(I)-Catalyzed Cross-Coupling of Conjugated Ene-yne-ketones and Terminal Alkynes: Synthesis of Furan-Substituted Allenes

A new method for the synthesis of furan-substituted allenes via Cu(I)-catalyzed coupling of conjugated ene-yne-ketones with terminal alkynes has been developed. A wide range of functional groups are tolerated, and the products are obtained in good to excellent yields under mild conditions. A copper carbene migratory insertion is proposed as the key step in this transformation with conjugated ene-yne-ketones as carbene precursors.