Recently, the use of Cu(I)/(II) salts and complexes as catalysts in organic synthesis has received increased attention due to their easy availability, non-toxicity, ease of handling and low cost.20–29 Although it has been known for decades that CuBr NH 3 (Glaser coupling)30 and CuCl·TMEDA (TMEDA = N,N,N′,N′-tetramethylethylenediamine, Hay coupling31) could be used as a catalyst for the oxidative homocoupling of terminal alkynes in an atmosphere of ...
