Synthesis of 5-(trifluoroacetyl)imidazoles from Bromoenones and Benzimidamides via Aza-Michael Initiated Ring Closure Reaction

Alexey R Romanov; Evgeniy V Kondrashov; Sergey V Zinchenko

doi:10.2174/1570179420666230420100643

Synthesis of 5-(trifluoroacetyl)imidazoles from Bromoenones and Benzimidamides via Aza-Michael Initiated Ring Closure Reaction

Curr Org Synth. 2024;21(2):195-209. doi: 10.2174/1570179420666230420100643.

Authors

Alexey R Romanov¹, Evgeniy V Kondrashov¹, Sergey V Zinchenko¹

Affiliation

¹ The Laboratory of Halogen Organic Compound, A. E. Favorsky Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, Irkutsk, 664033, Russia.

PMID: 37078355
DOI: 10.2174/1570179420666230420100643

Abstract

Introduction: A simple method for the preparation of 5-(trifluoroacetyl)imidazoles was elaborated.

Methods: The reaction of trifluoromethyl(α-bromoalkenyl)ketones with benzimidamides was employed to afford the target heterocycles in good yields.

Results: The assembly of imidazole core proceeds via aza-Michael adduct formation followed by intramolecular nucleophilic substitution and spontaneous aromatization as an oxidation sequence.

Conclusion: The yields of target imidazoles can be improved by the use of soft oxidizing agents.

Keywords: CF3-bromoenones; Fluorine-bearing azaheterocycles; aza-MIRC synthesis; aza-Michael addition; imidazoles; oxidizing agents..