Diisobutylaluminum hydride-promoted cyclization of benzyl and phenylsilyl ethers bearing a 2-(trimethylsilyl)ethynyl group: syntheses of indenes and benzosiloles
proceeds by regio- and stereoselectivehydroalumination of the alkyne moiety followed by intramolecular nucleophilic substitution. o-[2-(Trimethylsilyl)ethynyl]phenylsilyl methyl ethers also underwent the DIBAL-H promoted-cyclization to be converted into 2-(trimethylsilyl)benzosiloles in good yields. This approach provides straightforward and efficient way to construct benzosiloles from readily available