Palladium-catalyzed multicomponent synthesis of 2-imidazolines from imines and acid chlorides

Molecules. 2012 Nov 22;17(12):13759-68. doi: 10.3390/molecules171213759.

Abstract

We describe the palladium-catalyzed multicomponent synthesis of 2-imidazolines. This reaction proceeds via the coupling of imines, acid chlorides and carbon monoxide to form imidazolinium carboxylates, followed by a decarboxylation. Decarboxylation in CHCl(3) is found to result in a mixture of imidazolinium and imidazolium salts. However, the addition of benzoic acid suppresses aromatization, and generates the trans-disubstituted imidazolines in good yield. Combining this reaction with subsequent nitrogen deprotection provides an overall synthesis of imidazolines from multiple available building blocks.

MeSH terms

  • Carbon Monoxide
  • Carboxylic Acids
  • Catalysis*
  • Chlorides / chemical synthesis
  • Chlorides / chemistry
  • Decarboxylation
  • Imidazoles* / chemical synthesis
  • Imidazoles* / chemistry
  • Imines* / chemical synthesis
  • Imines* / chemistry
  • Molecular Structure
  • Palladium / chemistry*

Substances

  • Carboxylic Acids
  • Chlorides
  • Imidazoles
  • Imines
  • Palladium
  • Carbon Monoxide
  • 2-imidazoline