Cu(I)-catalyzed regioselective synthesis of pyrazolo[5,1-c]-1,2,4-triazoles

J Org Chem. 2012 Jul 6;77(13):5813-8. doi: 10.1021/jo300611a. Epub 2012 Jun 13.

Abstract

Cycloadditions of terminal alkynes to 1,2,4-triazolium N-imides in the presence of base and Cu(I) afford pyrazolo[5,1-c]-1,2,4-triazoles regioselectively. The scope of alkynes, the influence of the electronic nature of the leaving group, and variations in the 1-alkyl substituent were examined. Quantum chemical calculations were employed to explain the distinct reactivity of the propiolates.

MeSH terms

  • Catalysis
  • Copper / chemistry*
  • Molecular Structure
  • Organometallic Compounds / chemistry*
  • Pyrazoles / chemistry*
  • Quantum Theory
  • Stereoisomerism
  • Triazoles / chemistry*

Substances

  • Organometallic Compounds
  • Pyrazoles
  • Triazoles
  • Copper