Tracking gold acetylides in gold(I)-catalyzed cycloisomerization reactions of enynes

The intermediacy of gold acetylides in the gold(I)-catalyzed cycloisomerization of enynes was questioned. While dinuclear gold complexes are observed under electrospray ionization conditions, the solution reactivity of gold acetylides also leads to the conclusion of their high affinity for the second coordination of a gold moiety, leading to dinuclear gold complexes. However, the involvement of gold acetylides and the corresponding diaurated species in the elementary steps of cycloisomerization mechanisms of enynes appears unlikely.