In-Flow Generation of Thionyl Fluoride (SOF) Enables the Rapid and Efficient Synthesis of Acyl Fluorides from Carboxylic Acids.

Herein, we report an approach for generating thionyl fluoride (SOF) from the commodity chemicals thionyl chloride (SOCl) and potassium fluoride (KF). The methodology relies on a microfluidic device that can efficiently produce and dose this toxic gaseous reagent under extremely mild and safe conditions. Subsequently, the in situ-generated thionyl fluoride is reacted with an array of structurally and electronically differing carboxylic acids, leading to the direct and efficient synthesis of highly sought-after acyl fluorides.