Fluorothiazynes as SuFEx Ambiphiles: Interconversion to Amino-sulfurdiimidoyl Fluorides

Sulfur(VI) functional groups are ubiquitous in medicinal chemistry, valued for their stability and ability to modulate molecular properties. While sulfonamides, sulfones, and sulfates dominate existing drug scaffolds, more complex, multidirectional sulfur(VI) cores remain underexplored. Here, we show a viable route from amino difluorothiazynes to aminosulfurdiimidoyl fluorides (ASDFs), via sequential alkylation and imination. Leveraging the ambiphilic character of fluorothiazynes-acting as both N-nucleophile and S-electrophile-we generate thiazynium intermediates that, upon trapping with primary amides, afford ASDFs in good yields. Additionally, the potential of ASDFs as SuFEx electrophiles is demonstrated by reaction with various nucleophiles. Notably, a sulfurdiimidamide derivative was generated, which is likely the first unsymmetrically substituted tetraimidosulfur species. This work expands the toolkit of azasulfur(VI) fluorides, introducing the first general route to ASDFs as stable, functionally diverse platforms for further chemical diversification.