Nickel-catalyzed cross-coupling of organoaluminum reagents with alkynylhalides for the synthesis of symmetrical and unsymmetrical conjugated 1,3-diynes derivatives

摘要

We describe a convenient method for the synthesis of symmetrical and unsymmetrical conjugated 1,3-diynes from cross-coupling reactions of organoaluminum with alkynylhalides: The cross-coupling reaction of organoaluminum (0.75 mmol) with alkynylhalides (0.5 mmol) mediated by Ni(acac)(2) (5 mol %)/DPPE(10 mol%) at room temperature in DME may produce symmetrical and unsymmetrical conjugated 1,3-diynes in moderate to good yields(up to 98%) derivatives. Their structures have been determined by HRMS and H-1(C-13)NMR data. On the basis of the experimental results, a possible catalytic cycle has been proposed. (C) 2019 Elsevier B.V. All rights reserved.