Use of a Semihollow-Shaped Triethynylphosphane Ligand for Efficient Formation of Six- and Seven-Membered Ring Ethers through Gold(I)-Catalyzed Cyclization of Hydroxy-Tethered Propargylic Esters
The formation of six‐ and seven‐membered ring ethers from hydroxy‐tethered propargylic esters was efficientlycatalyzed by a cationic gold(I) complex with a semihollow‐shaped triethynylphosphane ligand. This gold catalysis showed a tolerance toward the reactions of primary, secondary, and tertiary alcohol substrates with various substitution patterns. A sterically congested 2,2,6,6‐tetraalkyl‐substituted