Synthesis of indoles via a tandem benzannulation-cyclization strategy

Abstract

Vinylketenes (generated in situ from cyclobutenones or a-diazo ketones) react with ynamides via a pericyclic cascade process to produce highly-substituted aniline derivatives. Cyclization of the benzannulation products can then be achieved via several alternate procedures leading to indoles that are highly substituted on the six-membered ring. The cyclization approaches investigated as the second step in this tandem strategy included aromatic substitution, palladium-catalyzed oxidative amination, and nucleophilic cyclization. This thesis discusses the scope and limitations of this tandem strategy.