Practical Oxidative Homo‐ and Heterocoupling of Terminal Alkynes Catalyzed by Immobilized Copper in MCM‐41

Abstract

Abstract A practical oxidative homo‐ and heterocoupling of terminal alkynes was achieved in CH 2 Cl 2 at 25 °C by using a 3‐(2‐aminoethylamino)propyl‐functionalized MCM‐41‐immobilized copper(I) complex (MCM‐41–2N‐CuI, 1 mol‐%) as the catalyst, piperidine (0.1 or 3 equiv.) as the base, and air as the environmentally friendly co‐oxidant, yielding a variety of symmetrical and unsymmetrical 1,4‐disubstituted 1,3‐diynes in good to excellent yields. This heterogeneous copper catalyst showed a higher catalytic activity than CuI and can be recovered and recycled by a simple filtration of the reaction mixture and used for at least 10 consecutive runs without any decrease in activity.