Homogeneous Copper‐Catalyzed Cycloisomerization Reaction of Allenynes: Rapid Access to Functionalized Pyrroles

Abstract Homogeneous transition‐metal‐catalyzed alkyne cascade cyclization reaction has attracted much attentions over the past decades. However, the relevant homogeneous transition‐metal‐catalyzed cyclization of allenynes has seldom been explored probably due to noticeable chemo‐, regio‐, and stereoselectivity. Described herein is an efficient homogeneous copper‐catalyzed cycloisomerization reaction of allenynes, thus leading to a practical and atom‐economic access to an array of valuable functionalized pyrroles by formal [3 + 2] cycloaddition via Cu‐containing all‐carbon 1,4‐dipoles.