Herein, we report on the dimerization of terminal alkynes using various palladium catalysts under solvent-free mechanochemical conditions. When tetrakis­(triphenylphosphine)­palladium(0) was employed as the catalyst, we observed the 1,3-butadiyne as the major product. However, when we employed bis­(triphenylphosphine)­palladium­(II) dichloride as the catalyst, we observed the trans-enyne as the major product. When we used a polymer-supported bis­(triphenylphosphine)­palladium­(II) dichloride catalyst under liquid-assisted grinding conditions, we discovered the ability to tune the catalyst to generate either the diyne or trans-enyne as the major product, depending on the grinding medium.

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