How Are Alkynes Scrambled?

In an alkyne metathesis reaction, two compounds containing carbon-carbon triple bonds exchange their substituents. Such reactions play an important role in the synthesis of natural products, polymers, and other organic molecules, but limited insights have been gained to date into how the reactions are catalyzed. In his Perspective, Bunz highlights the report by Bino et al., who have isolated a compound that is a possible catalytic intermediate in certain alkyne metathesis reactions. The work is an important step on the road toward the ideal alkyne metathesis catalyst.