In-flow generation of thionyl fluoride (SOF2) enables the rapid and efficient synthesis of acyl fluorides from carboxylic acids

31 January 2024, Version 1
This content is a preprint and has not undergone peer review at the time of posting.


Herein, we report an approach for generating thionyl fluoride (SOF2) from the commodity chemicals thionyl chloride (SOCl2) 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. Importantly, our investigation also highlights the inherent modularity of this flow-based platform. We demonstrate the adaptability of this approach by not only synthesizing acyl fluorides, but also directly converting carboxylic acids into a diverse array of valuable compounds such as esters, thioesters, amides, and ketones. This versatility showcases the potential of this approach for a wide range of synthetic applications, underscoring its significance in the realm of chemical synthesis.


flow chemistry
acyl fluoride
Multistep Synthesis
On demand generation
gaseous reagents

Supplementary materials

Supporting Information
Experimental procedures, additional optimization tables, spectroscopic analysis


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