Copper(I) Iodide Catalyzed Cross-Coupling Reaction of Terminal Alkynes with 1-Bromoalkynes: A Simple Synthesis of Unsymmetrical Buta-1,3-diynes

A simple synthesis of unsymmetrical buta-1,3-diynes by cross-coupling of terminal alkynes with 1-bromoalkynes in the presence of copper(I) iodide and tris(o-tolyl) phosphine was developed that gives good yields under simple and mild reaction conditions. The scope and limitations of the cross-coupling reaction were investigated.