Synthesis of a 13-Bridged Macrobicyclic Enyne via Chemoselective Cycloisomerization Using Palladium-catalyzed Alkyne-Alkyne Coupling

摘要

A unique intramolecular Pd-catalyzed alkyne-alkyne coupling is presented. This transformation generates a strained, 1,3-bridged, macrocyclic enyne. The process was readily executed on gram-scale, and the structure of the product was elucidated via X-ray crystallographic analysis. A mechanistic rationale for the observed chemoselectivity is provided.