Use of 1-pentafluorosulfanyl-phenylacetylenes for the preparation of SF5-substituted five-membered ring heterocycles through 1,3-dipolar cycloadditions. Isoxazoles and isoxazolines

• 1,3-Dipolar cycloadditions of nitrile oxides and nitrones are reported.
• SF5-substituted alkynes are used in 1,3-dipolar cycloaddition reactions.
• Preparations of SF5-substituted isoxazoles and isoxazolines are reported.

A synthetic methodology utilizing 1,3-dipolar cycloadditions was developed for the preparation of pentafluorosulfanyl-substituted heterocycles using SF5-substituted arylacetylenes as key building block dipolarophiles. A group of 4-SF5-isoxazoles were prepared in moderate yields using in situ generated nitrile oxides, and 4-SF5-substituted isoxazolines were obtained when nitrones were used as the 1,3-dipole.

1,3-Dipolar cycloadditions of nitrile oxides and nitrones with SF5-substituted alkynes.Figure optionsDownload as PowerPoint slide