A Thiol-Mediated Three-Step Ring Expansion Cascade for the Conversion of Indoles into Functionalized Quinolines
Nantachai Inprung, Michael J. James, Richard J. K. Taylor, William P. Unsworth
Abstract
An operationally simple, high yielding three-step cascade process is described for the direct conversion of indole-tethered ynones into functionalized quinolines. A single "multitasking" thiol reagent is used to promote a three-step dearomatizing spirocyclization, nucleophilic substitution, and one-atom ring expansion reaction cascade under remarkably mild conditions. In addition, a novel route to thio-oxindoles is described, which was discovered by serendipity.
Topics & Concepts
ChemistryThio-Indole testCombinatorial chemistryCascadeRing (chemistry)ReagentThiolNucleophileNucleophilic substitutionNucleophilic aromatic substitutionSN2 reactionStereochemistryOrganic chemistryCatalysisChromatographySulfur-Based Synthesis TechniquesCatalytic C–H Functionalization MethodsCatalytic Alkyne Reactions