1,3-Diynes synthesis by homo-coupling of terminal alkynes using a Pd(PPh3)4/Ag2O simple catalyst system

Amine- and copper salt-free palladium-catalyzed homo-coupling reaction of terminal alkynes proceeded efficiently in the presence of silver(I) oxide, which served as both activator and oxidant, in tetrahydrofuran at 60 °C to achieve satisfactory yields of 1,3-diyne compounds. It was demonstrated for the first time by means of XPS analysis that Pd(0) species can be oxidated to Pd(II) by silver(I) oxide.

A simple palladium catalyst system was utilized for synthesis of 1,3-diynes, and the reaction conditions employed can tolerate ketone carbonyl group, hydroxy group, and an aldehyde group. The reaction mechanism was investigated through XPS analysis.Figure optionsDownload as PowerPoint slideHighlights
► Developed an efficient method for the synthesis of 1,3-diynes.
► A variety of terminal alkynes can be employed to synthesize 1,3-diynes.
► The reaction conditions can tolerate carbonyl and hydroxy groups.
► It was demonstrated that Pd(0) species can be oxidated to Pd(II) by Ag2O.