Two-Step Construction of Thiophene–Oxazole Dyads with Fluorescent Properties by the Ring Expansion of Aziridines

Abstract

A general approach toward 2-thiophenylsubstituted oxazoles using aziridination of a double bond of (acyl)alkenyl thiophenes with the subsequent expansion of the aziridine ring is developed. The isolation of intermediate aziridine is not necessary. This expedient protocol covers a broad scope of readily available 2-, 3-, and benzothiophene derivatives, is practical and reliable, requires short reaction times, and is simple to set up and work up reaction mixtures. Thiophenyloxazoles, obtained by this method, exhibit fluorescence with high quantum yields.

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