Oxidative Cascade Sulfonylation/Cyclisation of N‐Propargylindoles with Hantzsch Esters via Sulfur Dioxide Insertion

Abstract

AbstractAn oxidative sulfonylation/cyclisation of N‐propargylindoles with Hantzsch esters through sulfur dioxide insertion has been developed. The method uses Na2S2O5 as sulfur dioxide source along with 4‐alkyl‐substituted Hantzsch esters as radical precursors for accessing sulfonyl radicals, and allows for the synthesis of 2‐sulfonated 9H‐pyrrolo[1,2‐a]indoles.