Iodocyclization of Ethoxyethyl Ethers to Alkynes: A Broadly Applicable Synthesis of 3-Iodobenzo[b]furans

A wide variety of 3-iodobenzo[b]furans were readily prepared by iodocyclization of 2-alkynyl-1-(1-ethoxyethoxy)benzenes with the I(coll)₂PF₆−BF₃·OEt₂ combination. Aryl-, vinylic-, and alkyl-substituted alkynes undergo iodocyclization in good to excellent yields. The mechanism of the reaction is also discussed.