A 21 membered library of 2-(imidazo[1,5-alpha]pyridine-1-yl)-1,3,4-oxadiazoles is synthesized in an unprecedented short sequence starting from an Ugi tetrazole reaction with a cleavable isocyanide component. The intermediate tetrazole is subjected to an acetic anhydride-mediated cyclization, followed by a Huisgen-type rearrangement with acyl chlorides to afford the imidazopyridine-oxadiazole bis-heterocycles. The scope and limitations of the methodology were investigated with substitutions on both the oxadiazole and the imidazopyridine rings. The introduced enabling technology for imidazopyridine oxadiazole synthesis combines a short reaction sequence with high scaffold diversity, based on commercially available starting materials and high functional groups tolerance.
- MCR chemistry
- Huisgen rearrangement
- SPECTRAL-LUMINESCENT PROPERTIES
- 1,3,4-OXADIAZOLE DERIVATIVES