A Highly Active CuI/TMEDA Catalytic System for the Coupling Reaction of Acid Chlorides with Terminal Alkynes under Solvent-Free Conditions

A highly efficient copper(I) iodide/N,N,N',N'-tetramethylethylenediamine (CuI/TMEDA) catalytic system for the synthesis of ynones has been developed. A variety of terminal alkynes, including 4-iodophenylacetylene, were smoothly coupled with acid chlorides in the presence 2 mol% CuI and 5 mol% TMEDA to afford the corresponding ynones in good to excellent yields in a short time. It is noteworthy that the reaction is conducted under solvent-free conditions at room temperature.