Synthesis of Pyridine-SF 4 -Isoxazolines Using the Functionality of trans -Tetrafluoro-λ 6 -sulfanyl Rodlike Linkers.

The tetrafluoro-λ ⁶ -sulfanyl (SF ₄ ) moiety has been relatively undeveloped since its discovery in the 1970s. In this study, we synthesized pyridine-SF ₄ -isoxazolines, in which the two heterocycles are connected by a rodlike trans -SF ₄ linker, via the regioselective 1,3-dipolar cycloaddition of pyridine-SF ₄ -alkynes and nitrones in the presence of triethylamine. SF ₄ linkers are a viable alternative to para-substituted benzenes, alkynes, and bicyclo[1.1.1]pentyl derivatives in drug design, and pyridine-SF ₄ -isoxazolines have potential applications in drug development.