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†
Abstract
An efficient cross-coupling of alkynes with alkynyl and alkenyl halides catalysed by a Ni–Cu system without any ligand has been achieved. The reaction is suggested to proceed by Ni(0) catalysis assisted by Cu(I). A series of functionalised diaryl, aryl–alkyl, aryl–heteroaryl, diheteroaryl 1,3-di-ynes and en-ynes are obtained in high yields.