Synthesis of C2 Substituted Benzothiophenes via an Interrupted Pummerer/[3,3]-Sigmatropic/1,2-Migration Cascade of Benzothiophene S-Oxides

Research output: Contribution to journalArticle

  • External authors:
  • Zhen He
  • Harry Shrives
  • Jose A Fernandez-Salas
  • Alberto Abengozar
  • Jessica Neufeld
  • Kevin Yang

Abstract

Functionalized benzothiophenes are important scaffolds found in molecules with wide ranging biological activity and in organic materials. We describe an efficient, metal-free synthesis of C2 arylated, allylated and propargylated benzothiophenes. The reaction utilizes synthetically unexplored yet readily accessible benzothiophene S-oxides and phenols, allyl- or propargyl silanes in a unique cascade sequence. An interrupted Pummerer reaction between benzothiophene S-oxides and the coupling partners yields sulfonium salts that lack aromaticity and therefore allow facile [3,3]-sigmatropic rearrangement. The subsequently generated benzothiophenium salts undergo a previously unexplored 1,2-migration to access C2 functionalized benzothiophenes.

Bibliographical metadata

Original languageEnglish
JournalAngewandte Chemie
Early online date12 Mar 2018
DOIs
Publication statusPublished - 2018