Domino synthesis of 1,3-diynes from 1,1-dibromoalkenes: a Pd-catalyzed copper-free coupling method

Pd-catalyzed domino synthesis of 1,3-diynes was accomplished using 1,1-dibomoalkenes under copper-free coupling conditions. This domino procedure involves base mediated in situ generation of 1-bromoalkyne and its subsequent coupling to give 1,3-diyne. The optimized copper-free coupling method afforded good to high yields of symmetrical 1,3-diynes in a one-pot operation.