Direct Synthesis of Unsymmetrical 1,3-Butadiynes from Calcium Carbide and Aryl Iodides

A novel methodology for the one-pot synthesis of unsymmetrical 1,3-butadiynes directly by the reaction of calcium carbide with aryl iodides is reported. This reaction system uses a safe, inexpensive, and easily handled acetylene source, and is easy to manipulate. This protocol is not only highly productive and selective, but also tolerates a wide range of functional groups.