Recyclable Cu/C₃N₄ composite catalysed homo- and cross-coupling of terminal alkynes under mild conditions

A Cu/C₃N₄ composite was prepared and utilized as a highly efficient and environmentally friendly catalyst for the homo- & cross-coupling of terminal alkynes. Excellent functional group tolerance and good yields were observed with oxygen as an oxidant in an isopropanol solution (or as additive) under ambient conditions. Furthermore, the composite catalyst shows good recyclability and can be recovered simply and reused several times without significant loss in its catalytic activities.