(79-93% yields). Moreover, the reaction also took place when heteroaromatic (9-11) or ferrocenyl (12) derivatives were used (60-91% yields). Subsequently, we assessed the generality of the process in terms of alkyl carboxylic acids. Primary (13), secondary (14), and tertiary ( ) carboxylic compounds all yielded the corresponding acyl fluorides in good-to-excellent yields (78-95% yields). Similar success was observed when an α,β-unsaturated carboxylic acid was used (16, 81% yield). Moreover, several Boc-protected α-aminoacidic derivatives, such as glycine (17), alanine (18), leucine ( ), proline (20), and phenylalanine ( ), as well as nonnatural structures such as cyclovaline ( ) and azabicyclo[2.2.1]heptane-3-carboxylic acid (23) were smoothly converted into the targeted acyl fluoride derivatives (41-97% yield) with very little erosion of their enantiopurity (see SI). Finally, we demonstrated how the mild conditions of this approach make it suitable for the functionalization of structurally diverse bio-relevant compounds decorated with various functional groups, such as ibuprofen ( ), pinonic acid (25), biotin (26), dehydrocholic acid ( ), and gibberellic acid (28) (55-94% yields). Crucially, this method enables the exclusive formation of the acyl fluoride even in the presence of a ketone functionality (see 25 and 27), which would be rapidly converted into a difluorinated motif in the presence of other deoxyfluorinating reagents such as DAST or Deoxo-Fluor. After having found a set of optimal conditions to promote the formation of acyl fluorides and having assessed the generality of the scope, we embarked upon an endeavor to leverage the full potential of this class of compounds with this microfluidic device. As previously described, acyl fluorides are appealing intermediates to forge new carbon-carbon and carbon-heteroatom bonds. Exploiting the advantages offered by the modular flow chemistry approach, we envisioned a device comprising three sections (Scheme 3): the first module, in which SOCl2 is converted to SOF2 through Cl-F exchange; the second, in which the gaseous reagent is reacted with a carboxylic acid to yield the acyl fluoride; and the third, in which the acyl fluoride is finally mixed with a chosen nucleophile to furnish the target compound. This required re-optimization of the procedure (see the SI for details). Crucially, the equivalents of SOF2 were lowered to 1.1 to avoid subsequent undesired reaction with the nucleophilic component within the third module. This adjustment, in turn, mandated an extension of the residence time within the second module to 6 minutes to ensure optimal acyl fluoride formation. It is worth noting that the productive use of 1.1 equivalents of SOF2 in batch conditions would be extremely challenging to achieve, as the gas would inevitably evolve towards the headspace of the reactor. Under these finely tuned reaction conditions, our investigation was directed towards the exploration of potential coupling nucleophiles.