Synthesis of fluoro-functionalized diaryl-λ 3 -iodonium salts and their cytotoxicity against human lymphoma U937 cells.

Conscious of the potential bioactivity of fluorine, an investigation was conducted using various fluorine-containing diaryliodonium salts in order to study and compare their biological activity against human lymphoma U937 cells. Most of the compounds tested are well-known reagents for fluoro-functionalized arylation reactions in synthetic organic chemistry, but their biological properties are not fully understood. Herein, after initially investigating 18 fluoro-functionalized reagents, we discovered that the ortho -fluoro-functionalized diaryliodonium salt reagents showed remarkable cytotoxicity in vitro. These results led us to synthesize more compounds, previously unknown sterically demanding diaryliodonium salts having a pentafluorosulfanyl (SF5 ) functional group at the ortho -position, that is, unsymmetrical ortho -SF5 phenylaryl-λ3 -iodonium salts. Newly synthesized mesityl(2-(pentafluoro-λ6 -sulfanyl)phenyl)iodonium exhibited the greatest potency in vitro against U937 cells. Evaluation of the cytotoxicity of selected phenylaryl-λ3 -iodonium salts against AGLCL (a normal human B cell line) was also examined.