Brønsted-base-catalyzed remote cascade reactivity of 2,4-dienones - asymmetric synthesis of tetrahydrothiophenes

Org Biomol Chem. 2017 Nov 22;15(45):9566-9569. doi: 10.1039/c7ob02397a.

Abstract

This study demonstrates that the remote cascade functionalization of 2,4-dienones can be realized by employing Brønsted base catalysis. The developed cascade involving 1,6-addition followed by the intramolecular aldol reaction provides a straightforward access to polysubstituted tetrahydrothiophene derivatives of biological and synthetic importance. Target products, bearing three contiguous stereocenters including one quaternary, have been obtained with excellent yields (up to 98%) and with good to high stereocontrol (>20 : 1 dr, up to 97 : 3 er) with the reaction cascade being promoted by a simple and readily available cinchona alkaloid cinchonine.

MeSH terms

  • Alkaloids / chemistry*
  • Catalysis
  • Ketones / chemistry*
  • Molecular Structure
  • Thiophenes / chemical synthesis*
  • Thiophenes / chemistry

Substances

  • Alkaloids
  • Ketones
  • Thiophenes
  • tetrahydrothiophene