Base-mediated hydroamination of propargylamine: a regioselective intramolecular 5-exo-dig cycloisomerization en route to imidazole-2-thione

Org Lett. 2014 Nov 7;16(21):5788-91. doi: 10.1021/ol502871r. Epub 2014 Oct 29.

Abstract

An intramolecular transition-metal-free base-mediated hydroamination of propargylamine with isothiocyanates has been achieved. This atom-economical, regioselective intramolecular 5-exo-dig cycloisomerization was utilized for the one-pot synthesis of diversely substituted imidazole-2-thione and spiro-cyclic imidazolidine-2-thione. The reaction goes to completion at room temperature via propargylthiourea and 65-97% isolated yields were obtained.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Catalysis
  • Cyclization
  • Ethylenethiourea / chemistry*
  • Gold / chemistry*
  • Imidazoles / chemical synthesis*
  • Imidazoles / chemistry
  • Molecular Structure
  • Pargyline / analogs & derivatives*
  • Pargyline / chemistry
  • Propylamines / chemistry*
  • Stereoisomerism
  • Thiones / chemical synthesis*
  • Transition Elements / chemistry*

Substances

  • Imidazoles
  • Propylamines
  • Thiones
  • Transition Elements
  • propargylamine
  • Ethylenethiourea
  • Gold
  • imidazole
  • Pargyline