General and Facile Synthesis of Indoles with Oxygen-Bearing Substituents at the Benzene Moiety

Indoles with oxygen-bearing substituents such as a methoxy or (triisopropylsilyl)oxy group at all of the positions of the benzene moiety were synthesized by cyclization of tert -butyl methoxy(or (triisopropylsilyl)oxy)-2-((trimethylsilyl)ethynyl)phenyl)carbamates with potassium tert -butoxide in tert -butyl alcohol. The (ethynylphenyl)carbamates were synthesized by the palladium-catalyzed reaction of (trimethylsilyl)acetylene and the corresponding (iodophenyl)carbamates, which were selectively synthesized by directed lithiation of the phenylcarbamates and subsequent iodination.