Ex situ Generation of Thiazyl Trifluoride (NSF3) as a Gaseous SuFEx Hub**.

Sulfur(VI)‐fluoride exchange (SuFEx) chemistry, an all‐encompassing term for substitution events that replace fluoride at an electrophilic sulfur(VI), enables the rapid and flexible assembly of linkages around a SVI core. Although a myriad of nucleophiles and applications works very well with the SuFEx concept, the electrophile design has remained largely SO2‐based. Here, we introduce S≡N‐based fluorosulfur(VI) reagents to the realm of SuFEx chemistry. Thiazyl trifluoride (NSF3) gas is shown to serve as an excellent parent compound and SuFEx hub to efficiently synthesize mono‐ and disubstituted fluorothiazynes in an ex situ generation workflow. Gaseous NSF3 was evolved from commercial reagents in a nearly quantitative fashion at ambient conditions. Moreover, the mono‐substituted thiazynes could be extended further as SuFEx handles and be engaged in the synthesis of unsymmetrically disubstituted thiazynes. These results provide valuable insights into the versatility of these understudied sulfur functionalities paving the way for future applications. [ABSTRACT FROM AUTHOR]