Synthesis of fluorine containing glycolurils and oxazolines from oxides of internal perfluoroolefins

The reaction of oxides of internal perfluoroolefins 1–3 with urea gave two kinds of novel fluorine containing N-heterocyclic compounds depending on the solvent nature: 1,5-bis(perfluoroalkyl)tetraazabicyclo[3.3.0]octane-3,7-diones 4a–c and 2-amino-5-fluoro-4,5-bis(perfluoroalkyl)-4,5-dihydrooxazol-4-ols 7a–d. Use of polar dimethylsulfoxide, N,N-dimethylacetamide and acetonitrile afforded glycolurils 4a–c in moderate yields. In dioxane, unexpected cyclization occurred resulting in oxazolines 7a–d in high yields. A similar reaction of oxiranes 2, 3 with urea in aqueous dioxane gave mixtures of 4,5-dihydroxy-4,5-bis(perfluoroalkyl)imidazolidine-2-ones 9b, c, glycolurils 4b, c and oxazolines 7b–d. The molecular structure of trans-isomers of oxazoline 7b and imidazolidine 9b has been established by X-ray crystallography.

Graphical abstractThe reaction of oxides of internal perfluoroolefins with urea in polar solvents – dimethylsulfoxide, N,N-dimethylacetamide and acetonitrile – gave 1,5-bis(perfluoroalkyl)tetraazabicyclo[3.3.0]octane-3,7-diones, in moderate yields. In dioxane, unexpected cyclization occurred resulting in 2-amino-5-fluoro-4,5-bis(perfluoroalkyl)-4,5-dihydrooxazol-4-ols, in high yields. Use of aqueous dioxane resulted in mixtures of oxazolines and glycolurils as minor and 4,5-dihydroxy-4,5-bis(perfluoroalkyl)imidazilidine-2-ones as major reaction products.Figure optionsDownload full-size imageDownload as PowerPoint slide