(Pentamethylcyclopentadienyl)Iridium Dichloride Dimer {[IrCp*Cl2]2}: A Novel Efficient Catalyst for the Cycloisomerizations of Homopropargylic Diols and N‐Tethered Enynes

Abstract (Pentamethylcyclopentadienyl)iridium dichloride dimer {[IrCp*Cl2]2}‐catalyzed hydroalkoxylation of bis‐homopropargylic alcohols provides an efficient access to dioxabicyclo[2.2.1]ketals. The cycloisomerizations proceed under mild conditions, with low catalytic loadings and short reaction times. This new protocol involving an Ir(III) catalyst also promoted the cycloisomerization of nitrogen‐tethered 1,6‐enynes to give azabicyclo[4.1.0]heptenes, enhancing the synthetic potential of our method.