New Chemical Transformations Involving SO2 F2 -Mediated Alcohol Activation

Sulfuryl fluoride is a gas produced on a multi-ton scale for its use as a fumigant. In the last decades, it has gained interest in organic synthesis as a reagent with unique properties in terms of stability and reactivity when compared to other sulfur-based reagents. Sulfuryl fluoride has not only been used for sulfur-fluoride exchange (SuFEx) chemistry but also encountered applications in classic organic synthesis as an efficient activator of both alcohols and phenols, forming a triflate surrogate, namely a fluorosulfonate. A long-standing industrial collaboration in our research group drove our work on the sulfuryl fluoride-mediated transformations that will be highlighted below. We will first describe recent works on metal-catalyzed transformations from aryl fluorosulfonates while emphasizing the one-pot processes from phenol derivatives. In a second section, nucleophilic substitution reactions on polyfluoroalkyl alcohols will be discussed and the value of polyfluoroalkyl fluorosulfonates in comparison to alternative triflate and halide reagents will be brought to light.

Traceless N-Polyfluoroalkylation of Weakly Nucleophilic Nitrogen Containing Compounds

Here we report an efficient access to high-value N-polyfluoroalkyl anilines, primary polyfluoroalkylamines and N,N-bis(polyfluoroalkyl)amines, via N-polyfluoroalkylation of sulfonamides and phthalimide derivatives using sulfuryl fluoride (SO2F2). The in situ formation of polyfluoroalkyl fluorosulfonates from commercially available fluorinated alcohols and economical sulfuryl fluoride is highly advantageous given that some polyfluoroalkyl halides are ozone-depleting substances (ODS) regulated by the Montreal protocol. This general method is applied to the polyfluoroalkylation of a variety of sulfonamides, N-sulfonyl carbamates and phthalimide with a wide tolerance of functional groups. The process thus provides viable access for industry to N-(polyfluoroalkyl)anilines as well as primary and secondary N-(polyfluoroalkyl)amines, which are very valuable but not easily accessible building blocks for life science applications.