Investigation of (Me4N)SCF3 as a Stable, Solid and Safe Reservoir for S = CF2 as a Surrogate for Thiophosgene

While thiophosgene finds widespread usage on a multi-ton scale, its fluorinated counterpart S=CF2 is essentially unexplored in synthesis. Using experimental reactivity tests, ReactIR and computational techniques, we herein showcase that the solid (Me4N)SCF3 functions as a safe reservoir for S=CF2. A key feature is that the reactive electrophile is not simply released over time, but instead is liberated under activation with a protic nucleophile. The reactivity of S=CF2 is mild, allowing large-scale and late-stage synthetic applications without special reaction control. The mechanism was fully elucidated, including a rationalization of the role of the Me4N cation and the origins of selectivity.