Iridium-Catalyzed Intramolecular Cycloisomerization between Functionalized Alkyne with Aryl Vinyl Ether: Synthesis of 2-Vinyl-3-functionalized Methylbenzofurans.

We have developed cycloisomerization between an aryl vinyl ether and a functionalized alkyne, such as silylalkyne, to give 2,3-disubstituted benzofuran derivatives using [IrCl(cod)]2, PCy3, and NaBArF4. This catalyst system not only catalyzes the above cycloisomerization but also isomerize a terminal olefin to give an aryl vinyl ether.