Nickel-catalyzed cross-coupling reaction of acetylenic sulfones with alkynyl Grignard reagents: a facile method for the preparation of unsymmetrical 1,3-diynes

The cross-coupling reaction of acetylenic sulfones with acetylenic Grignard reagents was realized by using Ni(acac)2 as catalyst to afford unsymmetrical 1,3-diynes under mild conditions without homocoupling byproducts. By using this method, 1,4-diaryl-1,3-diynes could be obtained in moderate to good yields (59–83%), whereas, the yields for alkyl substituted 1,3-diynes are lower (30–54%).