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.
A highly efficient one-pot approach for the synthesis of carbonyl 2-amino-pyrimidines from 1,3-diynes and guanidine in the presence of Cs2CO3 and DMSO has been described. This methodology proves to be a tandem regioselective heterocyclization of 1,3-diynes with guanidine and selective oxidation.