Synthesis of tetrahydrothiopyrano[2,3-b]indoles via [3+3] annulation of nitroallylic acetates with indoline-2-thiones

Abstract

An efficient one-pot method has been developed for the regio- and stereoselective synthesis of thiopyran annulated indoles. It involves a base mediated cascade [3+3] annulation of indoline-2-thiones and nitroallylic acetates. The tetrahydrothiopyranoindoles which were formed in good yields and in a short reaction time could be easily transformed to triazole derivatives by taking advantage of the nitro group present in the skeleton.