Synthesis of (-)-epi-indolactam V by an intramolecular Buchwald-Hartwig C-N coupling cyclization reaction

J Org Chem. 2013 Aug 2;78(15):7727-34. doi: 10.1021/jo4013767. Epub 2013 Jul 25.

Abstract

The synthetic efforts toward the concise synthesis of (-)-indolactam V from simple and commercially available starting materials using palladium- and copper-catalyzed intramolecular N-arylation strategy for the elaboration of the requisite nine-membered lactam ring as the key step are described. The incorporation of a turn-inducing structural element along the linear precursor was fundamental to achieve the heterocyclization step as well as obtain the correct regio- and chemoselectivity. The stereoselective nature in the C-N coupling cyclization reaction is interpreted in terms of minimization of allylic strain at the transition state for the palladium-amido complex formation. Meanwhile, the synthesis of the (-)-epi-indolactam V and its enantiomer have been accomplished.

MeSH terms

  • Cyclization
  • Indoles / chemical synthesis*
  • Indoles / chemistry
  • Lactams / chemical synthesis*
  • Lactams / chemistry
  • Molecular Structure
  • Stereoisomerism

Substances

  • Indoles
  • Lactams
  • indolactam V