A co-operative Ni–Cu system for Csp–Csp and Csp–Csp2 cross-coupling providing a direct access to unsymmetrical 1,3-diynes and en-ynes

An efficient cross coupling of alkynes with alkynyl and alkenyl halides catalysed by a Ni–Cu system without any ligand leading to the synthesis of a series of functionalised 1,3-di-ynes and en-ynes has been achieved.