Selective Synthesis of Quinolines and Indoles: Sulfur-Assisted or Selenium-Catalyzed Reaction of [beta]-(2-Nitrophenyl)-[alpha],[beta]-unsaturated Ketones with Carbon Monoxide

A simple and selective synthetic method of quinolines and indoles by the reaction of [beta]-(2-nitrophenyl)-[alpha],[beta]-unsaturated ketones with carbon monoxide was developed. When [beta]-(2-nitrophenyl)-[alpha],[beta]-unsaturated ketones were allowed to react with carbon monoxide and water in the presence of a stoichiometric amount of sulfur or a catalytic amount of selenium, the corresponding quinolines were produced in moderate-to-good yields. On the other hand, in the absence of water, the indoles were produced by the selenium-catalyzed reaction of the [beta]-(2-nitrophenyl)-[alpha],[beta]-unsaturated ketones with carbon monoxide.