l-Proline Promoted Ullmann-Type Coupling Reactions of Aryl Iodides with Indoles, Pyrroles, Imidazoles or Pyrazoles

Abstract

The Ullmann-type coupling reactions of aryl iodides and several nitrogen heterocycles occur at 80-90 °C with l-proline as additive, giving N-arylpyrroles, N-arylindoles, N-arylimidazoles, and N-pyrazoles in good to excellent yields.

Key words

cross coupling - nitrogen heterocycles - catalysis - aryl iodide - additive

References

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8

For CuI catalyzed coupling reaction of amides with aryl halides under mild conditions, see ref. [5b] . We are investigating this coupling reaction using our conditions and the results will be reported in due course.