Ruthenium Catalyzed Tandem Pictet-Spengler Reaction

Org Lett. 2020 Jul 2;22(13):4979-4984. doi: 10.1021/acs.orglett.0c01485. Epub 2020 Jun 19.

Abstract

We report a pyridyl-phosphine ruthenium(II) catalyzed tandem alcohol amination/Pictet-Spengler reaction sequence to synthesize tetrahydro-β-carbolines from an alcohol and tryptamine. Our conditions use a Lewis acid cocatalyst, In(OTf)3, that is compatible with typically base catalyzed amination and an acid catalyzed Pictet-Spengler cyclization. This method proceeds well with benzylic alcohols, heterocyclic carbinols, and aliphatic alcohols. We also show how combining this reaction with a subsequent cycloamination enables a direct synthesis of tetracyclic alkaloids like harmicine.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Alcohols / chemistry
  • Amination
  • Catalysis
  • Ruthenium / chemistry*
  • Tryptamines / chemistry

Substances

  • Alcohols
  • Tryptamines
  • tryptamine
  • Ruthenium