Inside Back Cover: Synthesis of Conjugated Linear and Cyclic Polyynes by Selective Alkyne Metathesis

Alkyne metathesis was used to selectively form conjugated triynes. Owing to the reversible cleavage and formation of carbon–carbon triple bonds, the reaction operates under thermodynamic control. The potential of this approach was demonstrated through the synthesis of triyne precursors to [7]cumulenes, a pentayne, a heptayne, and macrocycles containing triyne motifs. More in the Communication (e23344) by Rik R. Tykwinski, Matthias Tamm, Marc Mauduit, Yann Trolez, and co-workers.