Direct Synthesis of Acyl Fluorides from Carboxylic Acids with the Bench-Stable Solid Reagent (Me 4 N)SCF 3 .

A convenient, highly efficient, and selective transformation of aliphatic and aromatic carboxylic acids to acyl fluorides is reported. In contrast to established approaches that require toxic or volatile additives and base and reaction control (i.e., cooling, slow addition), this protocol allows for a straightforward access to various R-COF entities upon direct reaction with the bench-stable, solid reagent (Me4 N)SCF3 at room temperature. The method is base- and additive-free, compatible with late-stage synthetic applications, high functional group tolerance, and facile target compound purification via filtration.